2014 Long-Term Reliability 

Assessment

November 2014

Table of Contents

Preface .................................................................................................................................................i

Executive Summary.............................................................................................................................. 1

Key Reliability Findings ........................................................................................................................ 2

1. Reserve Margins in Several Assessment Areas Trend Downward, Despite Low Load Growth........................................... 2

2. Environmental Regulations Create Uncertainty and Require Assessment......................................................................... 8

3. A Changing Resource Mix Requires New Approaches for Assessing Reliability ............................................................... 18

Other Reliability Issues.............................................................................................................................................................. 30

Assessment Area Reliability Findings.................................................................................................. 33

FRCC .................................................................................................................................................. 36

MISO.................................................................................................................................................. 38

MRO-Manitoba Hydro........................................................................................................................ 42

MRO-MAPP........................................................................................................................................ 45

MRO-SaskPower ................................................................................................................................ 47

NPCC-Maritimes................................................................................................................................. 51

NPCC-New England ............................................................................................................................ 54

NPCC-New York.................................................................................................................................. 60

NPCC-Ontario..................................................................................................................................... 63

NPCC-Québec..................................................................................................................................... 68

PJM.................................................................................................................................................... 72

SERC .................................................................................................................................................. 78

SPP .................................................................................................................................................... 82

TRE-ERCOT......................................................................................................................................... 85

WECC................................................................................................................................................. 89

Appendix I: 2014LTRA Reference Case Data Summary........................................................................ 96

Appendix II: Reliability Assessment Glossary.................................................................................... 101

Appendix III: 2014 Polar Vortex Scenario Analysis............................................................................ 105
NERC | 2014 Long-Term Reliability Assessment | November 2014

i

Preface

The North American Electric Reliability Corporation (NERC) has prepared the following assessment in accordance with the 

Energy Policy Act of 2005, in which the United States Congress directed NERC to conduct periodic assessments of the 

reliability and adequacy of the bulk power system (BPS) in North America.1NERC operates under similar obligations in many 

Canadian provinces, as well as a portion of Baja California Norte, Mexico.

NERC is an international regulatory authority established to evaluate and improve the reliability of the BPS in North America. 

NERC develops and enforces Reliability Standards; annually assesses seasonal and long-term (10-year) reliability; monitors 

the BPS through system awareness; and educates, trains, and certifies industry personnel. NERC is the electric reliability 

organization (ERO) for North America, subject to oversight by the U.S. Federal Energy Regulatory Commission (FERC) and 

governmental authorities in Canada.2

Reliability Standards are the planning and operating rules that electric utilities follow to support and maintain a reliable 

electric system. These standards are developed by the industry using a balanced, open, fair, and inclusive process accredited 

by the American National Standards Institute (ANSI). While NERC does not have authority to set Reliability Standards for 

resource adequacy (e.g., Reserve Margin criteria) or to order the construction of resources or transmission, NERC can 

independently assess where reliability issues may arise and identify emerging risks. This information, along with NERC 

recommendations, is then made available to policy makers and federal, state, and provincial regulators to support decision 

making within the electric sector.

NERC prepares seasonal and long-term assessments to examine the current and future reliability, adequacy, and security of 

the North American BPS. For these assessments, the BPS is divided into 20 assessment areas,3 both within and across the 

eight Regional Entity boundaries, as shown in the corresponding table and maps below.

4 The preparation of these 

assessments involves NERC’s collection and consolidation of data from the Regional Entities. Reference case data includes 

projected on-peak demand and energy, Demand Response (DR), resource capacity, and transmission projects. Data and 

information from each NERC Region are also collected and used to identify notable trends, emerging issues, and potential 

concerns. This bottom-up approach captures virtually all electricity supplied in the United States, Canada, and a portion of 

Baja California Norte, Mexico. NERC’s reliability assessments are developed to inform industry, policy makers, and regulators 

and to aid NERC in achieving its mission—to ensure the reliability of the North American BPS.

 

1 H.R. 6 as approved by of the One Hundred Ninth Congress of the United States, the Energy Policy Act of 2005. The NERC Rules of Procedure, Section 800, 

further detail the Objectives, Scope, Data and Information requirements, and Reliability Assessment Process requiring annual seasonal and long-term 

reliability assessments.

2 As of June 18, 2007, FERC granted NERC the legal authority to enforce Reliability Standards with all U.S. users, owners, and operators of the BPS and 

made compliance with those standards mandatory and enforceable. Equivalent relationships have been sought and for the most part realized in Canada 

and Mexico. Prior to adoption of §215 in the United States, the provinces of Ontario (2002) and New Brunswick (2004) adopted all Reliability Standards 

that were approved by the NERC Board as mandatory and enforceable within their respective jurisdictions through market rules. Reliability legislation is 

in place or NERC has memoranda of understanding with provincial authorities in Ontario, New Brunswick, Nova Scotia, Québec, Manitoba, Saskatchewan, 

British Columbia, and Alberta, and with the National Energy Board of Canada (NEB). NERC standards are mandatory and enforceable in Ontario and New 

Brunswick as a matter of provincial law. Manitoba has adopted legislation, and standards are mandatory there. In addition, NERC has been designated as 

the “electric reliability organization” under Alberta’s Transportation Regulation, and certain Reliability Standards have been approved in that jurisdiction; 

others are pending. NERC standards are now mandatory in British Columbia and Nova Scotia. NERC and the Northeast Power Coordinating Council 

(NPCC) have been recognized as standards-setting bodies by the Régie de l’énergie of Québec, and Québec has the framework in place for Reliability 

Standards to become mandatory. NEB has made Reliability Standards mandatory for international power lines. In Mexico, the Comisión Federal de 

Electricidad (CFE) has signed WECC’s reliability management system agreement, which only applies to Baja California Norte.

3

The number of assessment areas has been reduced from 26 to 20 since the release of the 2013LTRA.

4 Maps created using Ventyx Velocity Suite.
Preface

NERC | 2014 Long-Term Reliability Assessment | November 2014

ii

NERC Regions and Assessment Areas

 

5

FRCC Region and Assessment Area boundaries are the same.

6

The MISO footprint is primarily located in the MRO Region, with smaller portions in the SERC and RF Regions. For NERC’s assessments, the MRO Region 

oversees the collection of data and information from MISO.

7

The PJM footprint is primarily located in the RF Region, with smaller portions in the SERC Region. For NERC’s assessments, the RF Region oversees the 

collection of data and information from PJM.

FRCC – Florida Reliability 

Coordinating Council

FRCC5

MRO – Midwest Reliability 

Organization

MISO6

MRO-Manitoba Hydro

MRO-MAPP

MRO-SaskPower

NPCC – Northeast Power 

Coordinating Council

NPCC-Maritimes:

NPCC-New England

NPCC-New York

NPCC-Ontario

NPCC-Québec

RF – ReliabilityFirst

PJM7

SERC – SERC Reliability 

Corporation

SERC-East

SERC-North

SERC-Southeast

SPP RE – Southwest Power 

Pool Regional Entity

SPP

TRE – Texas Reliability Entity

TRE-ERCOT

WECC – Western Electricity 

Coordinating Council

WECC-CA/MX

WECC-NWPP 

WECC-RMRG 

WECC-SRSG 
Preface

NERC | 2014 Long-Term Reliability Assessment | November 2014

iii

The North American Electric Reliability Corporation

Atlanta

3353 Peachtree Road NE, Suite 600 – North Tower

Atlanta, GA 30326

404-446-2560

Washington, D.C.

1325 G Street NW, Suite 600

Washington, DC 20005

202‐400‐3000

Assessment Data Questions

Please direct all data inquiries to NERC staff (assessments@nerc.net). References to the data and/or findings of the 

assessment are welcome with appropriate attribution of the source to the NERC 2014 Long-Term Reliability Assessment. 

However, extensive reproduction of tables and/or charts will require permission from NERC staff.

NERC Reliability Assessment Staff

Name Position

Mark Lauby Senior Vice President and Chief Reliability Officer

Thomas Burgess Vice President and Director, Reliability Assessment and Performance Analysis

John N. Moura Director, Reliability Assessment

Ganesh Velummylum Senior Manager, Reliability Assessment

Noha Abdel-Karim Senior Engineer, Reliability Assessment

Trinh C. Ly Engineer, Reliability Assessment

Michelle Marx Administrative Assistant, Reliability Assessment and Performance Analysis

Amir Najafzadeh Engineer, Reliability Assessment

Elliott J. Nethercutt Senior Technical Analyst, Reliability Assessment

Pooja Shah Senior Engineer, Reliability Assessment

NERC Reliability Assessment Subcommittee Roster

Name Position Region/Organization Name Position Region/Organization

Layne Brown Chair WECC* Paul D. Kure Member RF

Ryan Westphal Vice Chair MISO James Leigh-Kendall Member SMUD

Mohammed Ahmed Member AEP Ben Lewiski Member MRO

Salva R. Andiappan Member MRO Bob Mariotti Member DTE Energy

Bagan Bagen Member Manitoba Hydro Joel B. Mathewson Member SERC

Richard Becker Member FRCC* John G. Mosier Member NPCC

Gary S. Brinkworth Member TVA Maryam Naghsh-Nilchi Member MISO

K.R. Chakravarthi Member SERC/Southern Company Vince Ordax Member FRCC

Digaunto Chatterjee Member MISO Paul Roman Member NYISO

Lewis De La Rosa Member TRE* John Seidel Member MRO

Barbara A. Doland Member SERC* Travis Tate Member SERC

Philip A. Fedora Member NPCC* Alan C. Wahlstrom Member SPP RE*

Tim FryFogle Member RF* Paul Walter Member MRO*/ATC

Chris Haley Member SPP Inc. Peter Warnken Member ERCOT

Kevan L. Jefferies Member OPG Ryan Westphal† Member MISO

Srinivas Kappagantula Member PJM Peter Wong Member ISO-NE

Esam A.F. Khadr Member PSE&G Brad Woods Member TRE

William B. Kunkel Member MRO Hurbert C. Young Member Scana

Mark J. Kuras Member PJM

Daniel Brooks Observer EPRI Tina G. Ko Observer BPA

Micheal Courchesne Observer ISO-NE Denise Lam Observer FRCC

Maria Haney Observer SERC Louise Nutter Observer FERC

Maria A. Hanley Observer DOE-NETL Alan Phung Observer FERC

Patricia Hoffman Observer DOE Michael Milligan Observer DOE-NREL
Preface

NERC | 2014 Long-Term Reliability Assessment | November 2014

iv

Assessment Preparation and Design

The 2014 Long-Term Reliability Assessment (2014LTRA) is based on resource adequacy8information collected from the eight 

Regional Entities (Regions) that is used to independently assess the long-term reliability of the North American BPS while 

identifying trends, emerging issues, and potential risks. The LTRA is developed annually by NERC in accordance with the ERO’s 

Rules of Procedure,9 as well as Title 18, § 39.1110 of the Code of Federal Regulations,11 also referred to as Section 215 of the 

Federal Power Act, which instructs NERC to conduct periodic assessments of the North American BPS.12

This assessment is based on data and information collected by NERC from the Regions on an Assessment Area-basis as of 

September 2014. The Reliability Assessment Subcommittee (RAS), at the direction of the Planning Committee (PC), supports 

the LTRA development. Specifically, NERC and the RAS perform a thorough peer review that leverages the knowledge and 

experience of industry subject matter experts while providing a balance to ensure the validity of data and information 

provided by the Regions. Each Assessment Area section is peer reviewed by members from other Regions to achieve a 

comprehensive review that is verified by the RAS in open meetings. The review process ensures the accuracy and

completeness of the data and information provided by each Region. This assessment has been reviewed and endorsed by the 

PC. The NERC Board of Trustees also reviewed and approved this report.

The 2014LTRA reference case does not reflect impacts that may result from the D.C. Circuit Court’s mandate to vacate FERC 

Order No. 745,

13 nor the impacts that may arise from the EPA’s proposed Clean Power Plan (Clean Air Act–Section 111(d)), 

currently open for public comment through December 1, 2014. While NERC provides a summary of the EPA’s proposed Clean 

Power Plan, quantitative impacts from these developments will be considered for inclusion in future NERC assessments.

Data Concepts and Assumptions Guide

The table below explains data concepts and important assumptions used throughout this assessment.

Data Concepts and Assumptions Guide

General Assumptions

The Reserve Margin calculation is an important industry planning metric used to examine future resource adequacy. This deterministic 

approach examines the forecast peak demand (load) and projected availability of resources to serve the forecast peak demand for the 

summer and winter of the 10-year outlook (2015–2024).

All data in this assessment are based on existing federal, state, and provincial laws and regulations.

Demand Assumptions

Electricity demand projections, or load forecasts, are provided by each Assessment Area.

Load forecasts include peak hourly load,14 or Total Internal Demand, for the summer and winter of each year.15

Total Internal Demand projections are based on normal weather (50/50 distribution)16 and is provided on a coincident basis for most 

Assessment Areas.17

 

8 Adequacy means having sufficient resources to provide customers with a continuous supply of electricity at the proper voltage and frequency, virtually all 

of the time. Resources refer to a combination of electricity-generating and transmission facilities that produce and deliver electricity, and demandresponse programs that reduce customer demand for electricity. Adequacy requires System Operators and planners to account for scheduled and 

reasonably expected unscheduled outages of equipment, while maintaining a constant balance between supply and demand.

9 NERC Rules of Procedure - Section 803.

10 Section 39.11(b) of the U.S. FERC’s regulations provide: “The Electric Reliability Organization shall conduct assessments of the adequacy of the BulkPower System in North America and report its findings to the Commission, the Secretary of Energy, each Regional Entity, and each Regional Advisory 

Body annually or more frequently if so ordered by the Commission.”

11 Title 18, § 39.11 of the Code of Federal Regulations.

12 BPS reliability, as defined in the How NERC Defines BPS Reliability section of this report, does not include the reliability of the lower-voltage distribution 

systems, which systems use to account for 80 percent of all electricity supply interruptions to end-use customers.

13 United States Court of Appeals for the District of Columbia Circuit - No.11-1486.

14 Glossary of Terms Used in NERC Reliability Standards.

15 The summer season represents June–September and the winter season represents December–February.

16 Essentially, this means that there is a 50 percent probability that actual demand will be higher and a 50 percent probability that actual demand will be 

lower than the value provided for a given season/year.

17 Coincident: The sum of two or more peak loads that occur in the same hour. Noncoincident: The sum of two or more peak loads on individual systems 

that do not occur in the same time interval. Meaningful only when considering loads within a limited period of time, such as a day, a week, a month, a 

heating or cooling season, and usually for not more than one year. SERC and FRCC calculate Total Internal Demand on a noncoincidental basis.
Preface

NERC | 2014 Long-Term Reliability Assessment | November 2014

v

Total Internal Demand includes considerations for reduction in electricity use due to projected impacts of energy efficiency and

conservation programs.

Net Internal Demand, used in all Reserve Margin calculations, is equal to Total Internal Demand, reduced by the amount of Controllable 

and Dispatchable Demand Response projected to be available during the peak hour.

Resource Assumptions

NERC collects projections for the amount of existing and planned capacity, and net capacity transfers (between Assessment Areas) that 

will be available during the forecast hour of peak demand for the summer and winter seasons of each year. Resource planning methods 

vary throughout the North American BPS. NERC uses the following categories to provide a consistent approach for collecting and 

presenting resource adequacy:

Anticipated Resources

 Existing-Certain generating capacity: includes operable capacity expected to be available to serve load during the peak hour with 

Firm transmission.

 Tier 1 capacity additions: includes capacity that is either under construction or has received approved planning requirements.

 Firm Capacity Transfers (Imports minus Exports): transfers with Firm contracts.

Prospective Resources: Includes all Anticipated Resources, plus:

 Existing-Other capacity: includes operable capacity that could be available to serve load during the peak hour, but lacks Firm 

transmission and could be unavailable for a number of reasons.

 Tier 2 capacity additions: includes capacity that has been requested, but not received approval for planning requirements. Up to 

50 percent of total Tier 2 capacity is counted toward the Prospective Resources category.

 Expected (non-Firm) Capacity Transfers (Imports minus Exports): transfers without Firm contracts, but a high probability of 

future implementation. 

Adjusted-Potential Resources: Includes all Prospective Resources, plus:

 Tier 3 capacity additions: includes additional resources that do not meet Tier 2 requirements. Up to 10 percent of total Tier 3 

capacity is counted toward the Adjusted-Potential Resources category.

Reserve Margins

Reserve Margins: the primary metric used to measure resource adequacy, defined as the difference in resources (Anticipated, 

Prospective, or Adjusted-Potential) and Net Internal Demand, divided by Net Internal Demand, shown as a percentile.

Anticipated Reserve Margin =

(Anticipated Resources – Net Internal Demand)

Net Internal Demand

Prospective Reserve Margin = 

(Prospective Resources – Net Internal Demand)

Net Internal Demand

Adjusted-Potential Reserve Margin =

(Adjusted-Potential Resources – Net Internal Demand)

Net Internal Demand

Reference Margin Level: the assumptions of this metric vary by Assessment Area. Generally, the Reference Margin Level is typically 

based on load, generation, and transmission characteristics for each Assessment Area and, in some cases, the Reference Margin Level 

is a requirement implemented by the respective state(s), provincial authorities, ISO/RTO, or other regulatory bodies. If such a 

requirement exists, the respective Assessment Area generally adopts this requirement as the Reference Margin Level. In some cases, 

the Reference Margin Level will fluctuate over the duration of the assessment period, or may be different for the summer and winter 

seasons. If one is not provided by a given Assessment Area, NERC applies a 15 percent Reference Margin Level for predominately thermal 

systems and 10 percent for predominately hydro systems.

Fuel Types

NERC collects and presents data on the generation mix based on the general fuel type identified for each unit. The fuel type is based on 

the prime movers and primary fuel type codes identified in the Form EIA-860 and provided below:

18

Coal: Anthracite (ANT), Bituminous (BIT), Lignite (LIG), Subbituminous (SUB), Waste/Other (WC), Refined (RC)

Petroleum: Distillate Fuel Oil (DFO), Jet Fuel (JF), Kerosene (KER), Petroleum Coke (PC), Residual Fuel Oil (RFO), Waste/Other Oil (WO)

Natural Gas: Blast Furnace (BFG), Natural (NG), Other (OG), Propane (PG), Synthesis from Petroleum Coke Gas (SGP), Coal-Derived 

Synthesis Gas (SGC)

Biomass: Agricultural By-Products (AB) Municipal Solid Waste (MSW) Other Biomass Solids (OBS), Wood/Wood Waste Solids (WDS), 

Other Biomass Liquids (OBL), Sludge Waste (SLW), Black Liquor (BLQ), Wood Waste Liquids (WDL), Landfill Gas (LFG), Other Biomass Gas 

(OBG)

Renewables: Solar (SUN), Wind (WND), Geothermal (GEO), Hydroelectric (fuel type: WAT; primary mover: HY)

Pumped Storage: Pumped Storage (fuel type: WAT; primary mover: PS)

Nuclear: Nuclear (NUC)

 

18 Additional information on fuel codes and prime movers are available in the Form EIA-860.
NERC | 2014 Long-Term Reliability Assessment | November 2014

1

Executive Summary

The 2014 Long-Term Reliability Assessment (2014LTRA) is a report that provides a wide-area perspective on the adequacy of 

the generation, demand-side resources, and transmission systems necessary to meet system reliability needs over the next

decade. This assessment includes NERC’s independent identification of issues that may impact the reliability of the North 

American Bulk-Power System (BPS) to provide industry, regulators, and policy makers with adequate time to address or 

otherwise develop plans to mitigate potential reliability impacts caused by these issues. This assessment also documents 

current industry plans to maintain reliability during the next decade, advising regulators, policy makers, and the general public 

of existing and potential challenges, complexities, and interdependencies.

The electricity industry provided NERC with resource adequacy projections for the 2015–2024 assessment period. NERC 

independently assessed these projections and identified three key findings that will impact the long-term reliability of the 

North American BPS and materially change the way the system is planned and operated. These key findings are:

1. Reserve Margins in several Assessment Areas are trending downward, despite low load growth.

2. Environmental regulations create uncertainty and require assessment.

3. A changing resource mix requires new approaches for assessing reliability.

The on-peak resource mix has recently shifted to be predominately gas fired: now 40 percent, compared to 28 percent just 

five years ago.19 This trend is expected to continue, as retiring coal, petroleum, nuclear, and other conventional generation is 

largely being replaced by gas-fired capacity and variable energy resources (VERs).

20 The fundamental transformation of the 

resource mix—largely driven by environmental regulations, legislation, state and provincial incentives for additional VERs, 

and impacts of fuel prices, particularly for natural gas—presents new challenges for the electricity industry.

System planners should ensure System Operators have the tools and resources needed to maintain reliability in the midst of 

this transformation. For example, typical planning approaches focus on ensuring capacity is procured and available to meet 

the hour of peak demand for each season, perceived as the highest stress on the system. However, stresses during shoulder

periods or off-peak hours can introduce a different set of challenges, such as the management of overgeneration periods 

when generation exceeds demand; this is generally introduced by an excess of less-flexible resources. Additionally, gas

generation and other flexible resources need further study to ensure availability to balance load during off-peak and shoulder 

periods.

These changes also provide opportunities to the industry as more responsive gas-fired generators can provide System

Operators with needed flexibility to address additional VERs, such as wind and solar resources, on the system. Similarly, the 

application of energy storage and Demand-Side Management (DSM) technologies has the potential to offer approaches to 

meeting demand and balancing it with greater efficiency. New technologies (e.g., smart grid devices and applications, phasor 

measurement units (PMU), remedial action schemes, new forecasting capabilities, greater system awareness, etc.) can also 

advance the industry’s ability to dynamically control grid facilities and improve coordination between System Operators, grid 

resources, and the consumer.

In preparing this assessment, NERC examined key reliability indicators of resource adequacy projections, including load 

forecasts, projected resources, and transmission enhancements. Based on these projections and input from the industry, 

NERC identified three key reliability findings that each include a subset of issues that will impact resource adequacy, 

transmission adequacy, or system operations during the next decade. These findings are cross-cutting and interdependent,

as many of the issues present unique challenges to the electricity industry.

 

19 NERC 2009 Long-Term Reliability Assessment.

20 NERC IVGTF Reports.
NERC | 2014 Long-Term Reliability Assessment | November 2014

2

Key Reliability Findings

This section provides an overview of each key finding as well as the potential reliability impacts and corresponding importance 

of ERO-wide coordination in addressing them. Observations and recommendations will also be included for NERC, industry, 

and policy makers.

1. Reserve Margins in Several Assessment Areas Are Trending Downward, Despite Low Load Growth 

Planning Reserve Margins are the primary metric used in this assessment to consistently examine future resource adequacy 

and raise industry awareness of potential resource adequacy concerns.21

Declining Demand Growth and Projected Capacity Additions

According to the 2014LTRA reference case, the NERC-wide annual demand growth rate is 1.05 percent for the summer and 

0.97 percent for the winter, which are the lowest growth rates on record for both seasons.22 With lower rates of demand 

growth, the contribution of Demand Response (DR) has also plateaued in recent years, with minimal additional program 

growth projected in the reference case.23

NERC-Wide Demand: 10-Year Growth Rates (Summer and Winter) at Lowest Levels on Record

*Prior to the 2011LTRA, the initial year of the 10-year assessment period is the report year (e.g., the 10-year assessment period for the 1990LTRA 

is 1990–1999). The 2011LTRA and subsequent LTRAs examine the initial year of the assessment period as one year out (e.g., the 10-year assessment 

period for the 2011LTRA is 2012–2023).

Most Assessment Areas attribute stagnant demand growth to the ongoing projected economic indicators (typically based on 

either employment levels or gross domestic product (GDP)) in the residential, commercial, and industrial sectors. Energy 

efficiency and conservation programs, as well as time-of-use rate programs in many areas continue to drive lower energy 

growth, and in some cases, the correlation between economic growth and load growth is no longer positive. Distributed 

generation (distributed energy resources) in NPCC-Ontario (-0.09 percent load growth) and WECC-CA/MX (0.25 percent load 

growth) has also reduced end-use or grid-supplied electricity demand. The following map includes peak season demand 

growth rates for each Assessment Area.

 

21 Reserve Margin projections are presented in Appendix I.

22 Compound annual growth rate (CAGR) provides the year-over-year growth rate over the duration of the assessment period. It is derived as follows: 

CAGR = (Year 10 / Year 1)^(1 / 9) – 1.

23 When examining the peak season for each Assessment Area, NERC-wide Controllable and Dispatchable DR is projected to grow by 1.7 GW (increasing 

from 38.9 GW in 2015 to 40.6 GW in 2024).

0.97%

1.05%

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

0.0%

0.2%

0.4%

0.6%

0.8%

1.0%

1.2%

1.4%

1.6%

1.8%

2.0%

2.2%

2.4%

Gigawatt

Compound Annual Growth Rate (CAGR)

NERC LTRA

10-Year Summer Growth 10-Year Winter Growth Winter CAGR Summer CAGR
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

3

10-Year Compound Annual Growth Rate (Peak Season) Below 2 Percent for Most Assessment Areas

Decline 0-1% Growth 1-2% Growth >2% Growth

Total capacity additions have paralleled the ongoing declines in load growth, with only 99.6 GW (66.9 GW on peak) of Tier 1 

capacity additions projected during the next decade, compared to 150 GW projected in the 2011LTRA reference case. 

Additionally, 39 GW of capacity has retired since 2011, with another 44.6 GW24 of retirements projected by 2024.

NERC-Wide 10-Year Projected Capacity Additions Declining Since 201125

Considering the ongoing decline in load growth, fewer capacity additions are necessary to maintain adequate planning 

reserves. However, Anticipated Reserve Marginsforseveral Assessment Areas have been showing declining trends, especially 

when examining short-term projections in the prior three LTRA reference cases. 

 

24 Includes 21.7 GW of coal, 15.8 GW of natural gas, 4.5 GW of nuclear, 2 GW of petroleum, and 0.5 GW of other capacity retirements (summer ratings).

25 2011, 2012, and 2013LTRA data includes Future-Planned capacity additions. The 2014LTRA data includes Tier 1 capacity additions.

60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155

2014LTRA

2013LTRA

2012LTRA

2011LTRA

Gigawatts

On-Peak Nameplate
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

4

Short-Term (Year 2 Forecast) Anticipated Reserve Margins Show Declining Trends for Some Assessment Areas

*Due to changes to the WECC subregional boundaries, resulting in four subregions instead of nine, the 2014 Anticipated Reserve Margins are not 

shown for WECC-BASN and WECC-ROCK for this comparison.

In recent long-term assessments, NERC highlighted resource adequacy concerns, particularly in ERCOT, NPCC-New York, and 

MISO, as projections continued to reflect declining Anticipated Reserve Margins that fell below each area’s Reference Margin 

Level during the short term (1-5 years).

TRE-ERCOT: Recent Capacity Additions Elevate Planning Reserve Margins through 2018

Since ERCOT initially identified potential resource adequacy concerns in 2012, the RTO responded by incentivizing additional

participation in Demand Response (DR) and energy efficiency programs. More recently, new gas-fired resources totaling 2,112 

MW (summer rating) were added during the 2014 summer, which elevates ERCOT’s Anticipated Reserve Margin to 14.3 

percent in 2015. It will remain above the Reference Margin Level (13.75 percent) untilsummer 2018. Assuming the availability 

of less-certain Prospective Resources, including Tier 2 capacity additions, ERCOT will meet the Reference Margin Level for all 

years of the assessment period.

TRE-ERCOT Reserve Margins (Left) and Capacity Shortfall below the Reference Margin Level (Right)

26

 

26 The Frontera power plant (three natural-gas-fired units totaling 524 MW) is assumed to be available to serve peak load for all years in the 2014LTRA 

Reference Case. However, the plant’s owner recently announced plans to begin exporting 170 MW of capacity to Mexico as soon as 2015, and the entire 

524 MW in 2016 with the completion of certain transmission projects. ERCOT and the Frontera Facility’s owners have agreed on the reliability safeguards 

for ensuring the plant will be available if needed in an emergency and have filed those conditions with the U.S. Department of Energy as part of the 

plant’s export authorization.

0%

5%

10%

15%

20%

25%

30%

35%

40%

11 12 13 14 11 12 13 14 11 12 13 14 11 12 13 14 11 12 13 14 11 12 13 14 11 12 13 14 11 12 13 14 11 12 13 14

MISO MAPP NPCC-New

England

NPCC-New

York

NPCC-Ontario SERC-E SERC-N WECC-BASN* WECC-ROCK*

LTRA Year by Assessment Area

0%

3%

6%

9%

12%

15%

18%

21%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

0.1

1.9 3.0 3.7 5.0 5.8 6.9

0.00%

13.75%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Reserve Margin (%) Capacity Shortfall (GW)
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

5

TRE-ERCOT Capacity Additions and Retirements

Capacity Additions 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Cumulative Tier 1 Additions 2,801 3,724 4,528 5,410 5,650 5,650 5,650 5,650 5,650 5,650

Cumulative Tier 2 Additions 4,369 14,027 21,360 25,814 25,814 25,814 25,814 25,814 25,814 25,814

Retirements 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Cumulative Retirements -2,311 -2,430 -2,430 -2,430 -2,430 -3,270 -3,270 -3,270 -3,270 -3,270

Net Capacity Change 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Tier 1 Additions, Less Retirements 490 1,294 2,098 2,980 3,220 2,380 2,380 2,380 2,380 2,380

Tier 1 & Tier 2 Additions, Less Retirements 4,859 15,320 23,458 28,794 29,034 28,194 28,194 28,194 28,194 28,194

Additional Tier 1 capacity in TRE-ERCOT totals over 5.6 GW during the 10-year outlook, with an additional 25.8 GW of Tier 2 

additions, while projected retirements total 2.3 GW (including unit suspensions and mothballs).

It is also important to note the impacts of recent modifications to ERCOT’s load forecast method, which incorporates a neural 

network model to forecast daily energy. Additionally, ERCOT is now incorporating regional growth forecasts for each

customer class (residential, commercial, and industrial) instead of observing only non-farm employment as the economic 

driver. These new assumptions result in a compound annual growth rate (CAGR) of 1.29 percent for the 10-year summer 

demand projections in the 2014LTRA reference case—substantially lower than the 2.35 and 1.38 percent CAGRs reflected in 

the 2012LTRA and 2013LTRA reference cases, respectively.

MISO: Generator Retirements, Transfer Limitations, and Resource Procurement Contribute to Deficit Margins in 2016

MISO’s Anticipated Reserve Margin will drop below the Reference Margin Level (14.8 percent) in 2016, declining to 5.23 

percent by 2024. The Reference Margin Level for MISO is based on a 14.8 percent requirement as determined by the 1-dayin-10-year Loss of Load Expectation (LOLE) (MISO criteria). Accordingly, in 2016, MISO projects it will operate at the reliability 

level of approximately 2-days-in-10-year LOLE, increasing the likelihood that resources will not be sufficient to serve peak 

demand. The number of expected days-per-year of an LOLE is projected to increase throughout the assessment period.

Potential environmental regulations could further exacerbate resource adequacy concerns in the MISO footprint unless 

additional replacement capacity is built in a timely fashion.

MISO Reserve Margins (Left) and Capacity Shortfall below the Reference Margin Level (Right)

As MISO starts to operate at or near its Reference Margin Level, there is a higher likelihood that System Operators will call

Emergency Operating Procedures more frequently to access Emergency-Only resources, load-modifying resources, and 

behind-the-meter generation (BTMG). The contributing factors driving the projected deficit include:

 Increased retirements and suspensions (temporary mothballing) due to Environmental Protection Agency (EPA)

regulations and market forces and low natural gas prices

 Exclusion of low-certainty resources that were identified in the Resource Adequacy survey

0%

3%

6%

9%

12%

15%

18%

21%

24%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

2.3 1.5 3.6 4.9 6.0

8.8 10.2 12.3 13.8

0.0%

14.8%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Reserve Margin (%) Capacity Shortfall (GW)
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

6

 Exclusion of surplus of capacity in MISO South above the 1,000 MW transfer from the Planning Reserve Margin 

requirement (PRMR)

27

 Increased exports to PJM and the removal of non-Firm imports28

 Inadequate Tier 1 capacity additions 29

Considering the 8.6 GW of low-certainty resources captured in MISO’s generator survey, the projected 10.8 GW of 

retirements far exceed Tier 1 capacity additions of 3.6 GW. Even when taking into account Tier 2 capacity additions, more 

resources will be needed to address the ongoing load growth of 0.82 percent annually.

MISO Capacity Additions and Retirements

Capacity Additions 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Cumulative Tier 1 Additions 1,167 1,636 2,982 3,528 3,579 3,579 3,579 3,579 3,579 3,579

Cumulative Tier 2 Additions 626 642 642 642 642 642 642 642 642 642

Retirements 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Cumulative Retirements -3,867 -4,824 -6,424 -6,424 -7,224 -7,524 -9,124 -9,424 -10,524 -10,824

Net Capacity Change 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Tier 1 Additions, Less Retirements -2,699 -3,188 -3,442 -2,896 -3,645 -3,945 -5,545 -5,845 -6,945 -7,245

Tier 1 & Tier 2 Additions, Less Retirements -2,073 -2,546 -2,800 -2,254 -3,003 -3,303 -4,903 -5,203 -6,303 -6,603

NPCC-New York: Capacity Retirements and Limited Tier 1 Capacity Additions Result in the Anticipated Reserve Margin 

Falling Below the Reference Margin Level in 2017

The New York Independent System Operator (NYISO) currently has an Installed Reserve Margin (IRM) requirement of 17 

percent that extends from May 2014 to April 2015. However, because this requirement expires prior to the 2015 summer, a 

15 percent Reference Margin Level is applied for all seasons and years of the assessment period. While the Anticipated 

Reserve Margin for NPCC-New York falls below the 15 percent Reference Margin Level in 2017, the Prospective Reserve

Margin remains above for all seasons and years of the assessment period. NYISO reports inadequate capacity concerns in 

southeast New York beginning as soon as 2019.30 Future transmission reliability issues were identified in four regions of the 

state with ongoing capacity retirements and continued demand growth.

NPCC-New York Reserve Margins (Left) and Capacity Shortfall below the Reference Margin Level (Right)

Projected Tier 1 capacity additions in New York, based on the NYISO planning criteria, include only one 19 MW biomass unit, 

expected to be in service by the 2016 summer. As demand continues to grow at an average rate of 0.79 percent each year, 

 

27 For this assessment, 1,000 MW of capacity is transferred from the MISO South to the MISO North/Central Region pending the outcome of regulatory 

issues currently under FERC review.

28 Capacity sales (imports and exports) in MISO depend on decisions of the respective resource owners, assuming that the tariff requirements are met 

(including planning of necessary transmission of both the buying and selling areas). Regarding the removal of non-Firm imports, the MISO market 

monitor double-counted non-Firm imports in the 2013LTRA reference case. These imports are accounted for in the Reference Margin Level (PRMR).

29 In the MISO footprint, 91 percent of the load is served by utilities with an obligation to serve customers reliably and at a reasonable cost. Resource 

planning and investment in resources are part of state and locally jurisdictional integrated resource plans that only become certain upon the receipt of a 

Certificate of Public Convenience and Necessity (CPCN).

30 NYISO 2014 Reliability Needs Assessment.

0%

3%

6%

9%

12%

15%

18%

21%

24%

27%

30%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

0.6 1.0 1.4 1.7 1.9 2.2 2.5 2.7

0.0%

15.0%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Reserve Margin (%) Capacity Shortfall (GW)
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

7

planned retirements of natural gas, oil, and coal units during the initial years of the assessment period result in declining 

margins. The availability of Tier 2 capacity additions (3,688 MW) can help offset declining margins and alleviate resource 

adequacy concerns.

NPCC-New York Capacity Additions and Retirements

Capacity Additions 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Cumulative Tier 1 Additions 0 19 19 19 19 19 19 19 19 19

Cumulative Tier 2 Additions 88 2,002 2,653 3,682 3,688 3,688 3,688 3,688 3,688 3,688

Retirements 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Cumulative Retirements -422 -422 -771 -771 -771 -771 -771 -771 -771 -771

Net Capacity Change 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Tier 1 Additions, Less Retirements -422 -403 -752 -752 -752 -752 -752 -752 -752 -752

Tier 1 & Tier 2 Additions, Less Retirements -334 1,599 1,901 2,930 2,936 2,936 2,936 2,936 2,936 2,936

Key Reliability Finding #1

Reserve Margins in Several Assessment Areas Trend Downward, Despite Low Load Growth

Observations

The near-term impacts of the Mercury and Air Toxics Standard (MATS), recently finalized by the EPA, are factored into this assessment. 

However, uncertainty remains for a large amount of existing conventional generation that may be vulnerable to retirement resulting 

from additional pending regulations—particularly EPA’s recently proposed Clean Power Plan (section 111(d) of the Clean Air Act). 

These impacts are discussed in detail in Key Reliability Finding #2.

NERC does not have authority to set Reliability Standards for resource adequacy (e.g., reserve margin criteria) or order the 

construction of resources or transmission. However, NERC has the responsibility to independently assess where BPS reliability issues 

may arise and to identify emerging risks to resource adequacy.

Recommendations

Continued Heightened Awareness: NERC should continue to raise awareness of resource adequacy issues by coordinating regularly 

with involved parties (state regulators and public utility commissions), and support ongoing initiatives to effectively address declining 

reserve margins.

Further Assessment Using Probabilistic Analysis: NERC should leverage the 2014 Probabilistic Assessment (based on 2014LTRA

reference case data; scheduled for release in March 2015) to provide further insights on the resource adequacy concerns in MISO, 

ERCOT, and NPCC-New York. This probabilistic approach will examine resource adequacy from an energy perspective, offering a more 

in-depth understanding of the interplay between resource availability (with considerations for transmission constraints) and 

projected hourly demand. Additional information on these new approaches is provided in Key Reliability Finding #3.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

8

2. Environmental Regulations Create Uncertainty and Require Assessment

Environmental regulations at the state, provincial, and federal levels continue to be the primary drivers of ongoing 

retirements—primarily fossil-fired capacity. System planners are responding by aligning generation portfolios to comply with 

limits on cross-state air emissions, surface water regulation, and renewable portfolio standards. Accordingly, NERC continues 

to examine and report the corresponding resource adequacy implications and potential reliability concerns associated with 

these developments. 

The accelerated retirement of fossil-fired generation is expected, due to increasing costs for compliance with environmental 

regulations. Coal-fired power plants are especially vulnerable to the impacts of declining revenues due to lower prices of 

natural gas (i.e., because natural gas often is the marginal fuel and thus sets prices in RTO/ISO markets, and natural gas 

influences wholesale electricity prices in non-RTO markets, the current trend of lower natural gas prices tends to reduce 

electricity prices and corresponding electricity payments received by all generators).

31 Concurrent increases in the operating 

costs of coal plants are often related to the required installation of environmental control technologies. Before these capital 

investments are made, plant owners must consider the future life of the unit(s), current and future fuel costs and revenues 

compared to other fuel types, and the impacts of additional environmental regulations. Accordingly, 20.2 GW of mostly 

smaller coal-fired units were retired between 2011 and 2013, while an additional 20.8 GW are projected to retire by 2024.

32

NERC-wide, 10.3 GW of natural-gas-fired and 5 GW of petroleum-fired capacity—primarily less-efficient units that have 

reached the end of their lifespan—were retired between 2011 and 2013 and typically replaced with newer natural gas 

combined-cycle (NGCC) power plants.33 Additionally, five nuclear units totaling 4.3 GW have retired since 2011, including four 

units in the US and one unit in Canada34 despite the relatively lower fuel costs of nuclear compared to coal and natural gas, 

operations and maintenance costs.

35 The nuclear fleet in North America is projected to continue providing critical baseload 

capacity during the next decade, but operations and maintenance costs will continue to impact the economic viability of 

certain plants—particularly those that are smaller or older.

Cumulative Fossil-Fuel and Nuclear Retirements between 2011 and 2024 Total 83 GW

 

31 EIA Annual Energy Outlook - Issues in Focus: Implications of accelerated power plant retirements. 

32 Data for actual retirements (from 2011 to 2013) based on EIA Electric Power Monthly – February 2014 and Ventyx Velocity Suite. Capacity is based on 

the net summer rating. Projected retirements (2014-2024) are based on the 2014LTRA Reference Case.

33 IBID.

34 IBID.

35 NEI - Nuclear Energy in 2014: Status and Outlook. 

0

10

20

30

40

50

60

70

80

90

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Actual 2014 LTRA Reference Case

Gigawatts

Coal Natural Gas Nuclear Petroleum
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

9

According to the 2014LTRA reference case, an additional 44.2 GW of fossil-fired and nuclear capacity is projected to retire 

between 2014 and 2024.36 These projections are based on the assumption that current environmental regulations will remain 

unchanged; it does not include potential impacts of EPA’s recently proposed Clean Power Plan (section 111(d) of the Clean 

Air Act). An in-depth examination of the plan is provided in the next section, while the current status of existing environmental 

regulations is provided below.

Status of Existing Regulations

Mercury and Air Toxics Standards (MATS)

The EPA issued a rule in December 201137 to reduce emissions of toxic air pollutants from power plants. MATS was designed 

to reduce emissions from existing and planned coal- and oil-fired generators by requiring the installation of environmental 

controls. These controls typically involve the addition of dry sorbent injection systems and/or sulfur dioxide (SO2) scrubbers. 

Other environmental controls (such as fabric filters) are also considered as technologies that remove or limit heavy metal 

particulate emissions. However, the final rule allows for upgrades to existing electrostatic precipitators, potentially negating 

the need for expensive retrofits.

The MATS rule in its current form includes important modifications, such as the ability to apply for a one-year extension 

(beyond the 2015 deadline) to alleviate potential impacts to system reliability and to allow generator owners to install needed 

compliance equipment. Since the rule was implemented, over 107 applications have been submitted, and 98 have been 

granted.38 In the coming years, affected generation owners will continue to comply either by closing plants or investing in 

environmental controls and technologies to ensure compliance with all regulations.

Cross-State Air Pollution Rule (CSAPR) / Clean Air Interstate Rule (CAIR)

CSAPR was vacated in August 2012 by the U.S. Court of Appeals for the District of Columbia Circuit, at which point CAIR was 

reinstated. CAIR is designed as a cap-and-trade program aimed at reducing emissions of SO2 and nitrogen oxides (NOX) from 

fossil-fired units with capacities greater than 25 MW in 27 eastern states and the District of Columbia. The emissions caps 

went into effect in 2009 for NOX and in 2010 for SO2, and both caps are scheduled to be tightened in 2015. 

The flue-gas desulfurization scrubbers or dry sorbent injection systems required to comply with MATS will ultimately result 

in SO2 emissions falling to levels lower than the CAIR cap. Therefore, power plant emission controls that meet the SO2

emission requirement of MATS will also fall in compliance with the cap established by CAIR.

In April 2014, the U.S. Supreme Court reversed the D.C. Circuit’s judgment and remanded the case. In June 2014, the U.S. 

government filed a motion with the U.S. Court of Appeals for the D.C. Circuit to lift the stay of the CSAPR, which was accepted 

on October 23, 2014.

39

Clean Water Act (CWA) – Section 316(b)

Cooling water intake operation and structures are regulated under Section 316(b) of the CWA.40 The 316(b) rule is 

implemented by the state water permitting agencies through the National Pollution Discharge Elimination System (NPDES) 

permit program of the CWA. EPA provides state permitting agencies with regulatory guidance and standards to determine

the best technology available to protect aquatic life from impingement (being trapped against the intake screen) and 

entrainment (passing through the screens and into the plant’s cooling water system). Section 316(b) of the federal CWA 

requires that the location, design, construction, and capacity of cooling water intake structures for facilities reflect the best 

technology available for minimizing adverse environmental impact. The final rule was signed in May 2014 and released in 

 

36 While the assessment period for the 2014LTRA is 2015-2024, projected retirements for 2014 are included in this analysis.

37MATS was challenged in the U.S. Court of Appeals for the District of Columbia Circuit in White Stallion Energy Center et al. v. U.S. EPA. The case was 

heard in December 2013, and a decision was made in April 2014 to uphold the rule.

38 As of September 2014.

39 CSAPR - Motion to Lift Stay

40 33 U.S.C. section 1326.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

10

August 2014 in the Federal Register.

41 Section 316(b) and resulting impacts to existing and future resources will depend on 

how the rule is implemented in each state.

Coal Combustion Residuals (CCRs)

The CCRs proposed EPA rule would regulate coal ash to address the disposal risks from waste generated by electric utilities 

and independent power producers. The EPA is considering two possible options for public comment regarding the 

management of coal ash. Under the first proposal, the EPA would list these residuals as special wastes subject to regulation 

under subtitle C of the Resource Conservation and Recovery Act (RCRA) when destined for disposal in landfills or surface 

impoundments. Under the second proposal, the EPA would regulate coal ash under subtitle D of RCRA, the section for

nonhazardous wastes.42

Canadian Provincial Regulations

Canadian regulations for CO2 emissions were finalized in September 2012, establishing regulations to reduce emissions by 

requiring stringent performance standards for new coal-fired electricity generation units and to coal-fired units that have 

reached the end of their economic life. Additional impacts are expected as the rule comes into effect in July 2015, and units 

commissioned prior to 1975 will have reached the end life after 50 years, or by 2019 (whichever comes first, depending on 

whether some units adopt carbon capture and sequestration technology). Other provincial regulations have been or continue 

to be developed with coordination between the provincial and federal governments. 

Saskatchewan (MRO-SaskPower) is seeking greater flexibility to meet GHG regulations by working with the provincial and 

federal governments to develop an equivalency agreement. Development and finalization of federal regulations to limit CO2

from natural-gas-based electricity generation could cause Saskatchewan to modify operational use of existing gas units in 

order to remain compliant. Pending federal natural gas rules for electricity generation will impact the timing and nature of 

capital projects and potential retirements, and of replacement/new energy decisions. These regulations are constantly 

monitored and are included in resource adequacy assessments. Saskatchewan plans to include sufficient time to perform 

retrofits or replacements to meet required regulations. Saskatchewan has not yet experienced any reliability issues related 

to GHG regulations and is expected to effectively mitigate any that arise.

Ontario (NPCC-Ontario) was the first Canadian province to phase out coal-fired capacity in 2014, while adding replacement 

capacity including nuclear, natural-gas, and variety of renewable resources. Similarly, MRO-Manitoba Hydro, which is 

predominately hydro, has one smaller coal unit remaining that will be impacted by the Manitoba Climate Change and

Emissions Reduction Act and the Reduction of Carbon Dioxide Emissions from Coal-Fired Generation of Electricity 

Regulations.

43 This unit is already regulated such that it can only be operated to provide for emergency operations.

Overview of EPA’s Proposed Clean Power Plan44

The EPA proposed draft rule released in June 2014 is aimed at reducing carbon dioxide emission from power plants to 30 

percent below the 2005 levels by 2030.

45 According to the EPA analysis of the proposed plan, between 108 and 134 GW of 

fossil-fired and nuclear retirements would occur by 2020 (depending on the state of regional implementations of Options 1 

or 2).

46 The proposed plan would apply to all fossil-fired generating units that meet four combined qualification criteria: (1) 

 

41 Federal Register Notice - August 15, 2014.

42 EPA: Coal Combustion Residuals - Proposed Rule.

43 Reduction of Carbon Dioxide Emissions from Coal-Fired Generation of Electricity Regulations. 

44 Additional information and analysis of the proposed CPP was performed by Energy Ventures Analysis, Inc. (EVA) and provided to NERC in September 

2014 for use in this assessment.

45 EPA: Clean Power Plan Overview.

46 Regional implementation of Option 2 assumes 108 GW of retirements (includes CC, Coal, CT, Nuclear, O/G, and IGCC) by 2020. State implementation of 

Option 1 assumes 134 GW of retirements (includes CC, Coal, CT, Nuclear, O/G, and IGCC) by 2020. For additional information, see Regulatory Impacts 

Analysis for the Proposed Carbon Pollution Guidelines for Existing Power Plants and Emission Standards for Modified and Reconstructed Power Plants 

(June 2014) and supporting IPM Model documentation and data.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

11

units that commenced construction prior to January 8, 2014;47 (2) units with design heat input of more than 250 MMBtu/hour, 

(3) units that supply over one-third of their potential output onto the power grid, and (4) units that supply more than 219,000 

MWh/year on a three-year rolling average to the power grid.

48 Given these criteria, NERC estimates that nearly all U.S. fossilfired power plants will be subject to the rule. The timeline of the proposed plan is provided below.

EPA Proposed Clean Power Plan Timeline

Within one year of finalizing the rule—expected in June 2015—state environmental agencies must submit implementation 

plans to the EPA for approval. Submitted state-specific plans, due in June 2016, must outline requirements and enforceable 

limitations for affected generating units to meet the rule’s average CO2 emission rate goal for each state within two 

compliance periods: (1) an initial 10-year average interim emission rate limit for the period 2020–2029, and (2) a final annual 

emission rate limit starting in 2030.

The EPA provides states with an option to convert CO2 emission rate limitation into an annual mass-based limitation. It is 

likely that most states will elect to pursue this option due to the challenges state permitting agencies have in developing unitspecific emission rate limitations. The simpler mass-based 

CO2 emission cap program also negates the need for state 

legislative action to authorize agencies to limit plant output 

and enact an enforceable program for compliance with 

average emission rates.

The EPA would have one year to review and approve 

implementation plans for each state in June 2017. Under 

this schedule, impacted generating units would have two

and a half years to develop respective compliance strategies 

and potentially permit, finance, and build needed 

replacement capacity and transmission. In its current form, 

this implementation schedule would be a challenge for 

states to implement and for affected sources to comply 

with, especially given the expected legal challenges to both 

the EPA and state rules. In recognition of these challenges, 

the EPA would provide states with a one-year compliance 

extension to June 2017 if justification is provided and a twoyear extension (June 2018) for states that elect to develop

 

47 All sources starting construction after January 8, 2014, would be subject to new source performance standards and exempt from the EPA Clean Power 

Plan requirements.

48 Federal Register Proposed Rule - June 18, 2014.

EPA’s Proposed Clean Power Plan: Options 1 & 2

The EPA is proposing a best system of emission reduction (BSER) 

goal approach, referred to as Option 1, and is taking comment 

on a second approach referred to as Option 2.

Option 1: involves higher deployment of emission reduction but 

allows a longer time frame to comply (2030).

Option 2: has a lower deployment of emission reductions over 

a shorter time frame (2025) by each state. The proposed 

guidelines would also allow states to collaborate and to 

demonstrate emission performance on a multi-state basis, in 

recognition that electricity is transmitted across state lines.

The BSER is not intended to impact resource planning and does 

not dictate retirements, additions, or operating practices for 

individual units. Instead, it would provide state emission rate 

limits that would shape the future resource mix through state 

and market processes in subsequent years as SIPs and multistate plans are developed and implemented.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

12

multi-state (regional) programs (e.g., Regional Greenhouse Gas Initiative (RGGI)). While the EPA extensions apply to state 

plan submissions, the January 1, 2020, program start date for affected sources would not be extended. Therefore, the 

impacted fossil-fired units may be left with as little as six months to develop and implement compliance plans. Considering 

the number and variety of outcomes for each of the proposed rule scenarios, the industry should initiate planning

immediately upon approval of the final rule.

Based on EPA analysis of historical data about emissions and the power sector, the proposed Clean Power Plan is to create a 

consistent national formula for reductions, reflecting their building block assumptions. The formula applies the four building 

blocks to each state’s specific information, yielding a carbon intensity rate for each state.49 

Reliability Considerations for EPA’s Proposed Clean Power Plan

To comply with the proposed Clean Power Plan, states are expected to select the mass-based limitation approach over the 

emission rate approach due to its greater flexibility and ease to enforce and implement. While the power industry has been 

successful in complying with prior mass-based emission cap and trade programs (e.g., Acid Rain program, Clean Air Interstate 

Rule, and RGGI) without creating major electric grid reliability problems, the proposed Clean Power Plan impacts a larger 

amount of capacity (over 700,000 MW) in a relatively short time frame, potentially posing greater grid reliability impacts

compared to prior environmental compliance programs. Changes in generation resources, dispatch, and delivery require 

comprehensive local and regional reliability assessments. These assessments are needed to identify necessary transmission 

system enhancements to provide for reliable delivery, system stability, voltage support, and other system reliability needs. 

Accordingly, the following reliability challenges warrant further consideration by policy makers:

EPA Assumptions Require Accelerated Coal-Fired Reduction beyond the 2014LTRA Reference Case

Although the Clean Power Plan may not become enforceable until 2020, its effect may overshadow and change large retrofit 

capital decisions needed to comply with earlier EPA regulations—primarily the Mercury and Air Toxics Standards (MATS). 

EPA’s base case projections, with existing regulations, indicate that total coal-fired capacity will decline rapidly from

approximately 310 GW in 2012 to just 245 GW by 2016 and 243 GW by 2025. The EPA’s base case—including existing 

 

49 EPA Fact Sheet: Clean Power Plan - National Framework for States.

EPA’s Proposed Clean Power Plan: Four Building Blocks

The EPA projects that by 2030, compliance with the objectives will reduce U.S. power industry CO2 emissions to 30 percent below 

2005 levels. The EPA developed state-specific CO2 emission rates by applying the following four “best system of emission reduction” 

approaches and assumptions:

Make fossil fuel power plants more efficient by implementing a 6 percent (on average) unit heat rate improvement for all affected 

coal-fired units. The EPA suggests that some plants could further improve process efficiency by 4 percent through the adoption of 

best operational practices, and an additional 2 percent through capital upgrade investments. 

Use low-emitting power sources more by re-dispatching existing NGCC units before the coal and older oil/gas steam units. EPA draft 

rate limitations include CO2 reduction assumptions from the ongoing increases in the use of NGCC capacity (with up to a 70 percent 

capacity factor). This additional NGCC capacity (440 TWh/year) displaces coal (376 TWh/year) and oil/gas steam generation (64

TWh/year) by 2020, compared to 2012 levels.

Use more zero- and low-emitting power sources through building capacity by adding both non-hydro renewable generation and five 

planned nuclear units. EPA calculations assume qualifying non-hydro renewable generation can grow rapidly from 218 TWh/year in 

2012 to 281 TWh/year by 2020, to reach 523 TWh/year by 2030.

Use electricity more efficiently by significantly expanding state-driven Energy Efficiency programs to improve annual electricity 

savings by up to 1.5 percent of retail sales per year. The calculation assumes the states and industry can rapidly expand Energy 

Efficiency programs to increase savings from 22 TWh/year in 2012, to 108 TWh/year in 2020, and to 380 TWh/year by 2029. 

Ultimately, EPA energy efficiency assumptions suggest that electric power savings will outpace electricity demand growth, resulting 

in declining electricity usage from 2020 through 2030.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

13

regulations, but excluding potential impacts of the proposed Clean Power Plan—assumes a significant reduction in coal-fired 

capacity by 2016: 27.2 GW beyond what is projected in the 2014LTRA reference case.

The EPA released a report titled Regulatory Impacts Analysis for the Proposed Carbon Pollution Guidelines for Existing Power 

Plants and Emission Standards for Modified and Reconstructed Power Plants. According to this analysis, the state 

implementation of Option 1 would result in the largest reduction in coal to 193 GW by 2025, while the regional 

implementation of Option 2 would result in the smallest reduction in coal to 214 GW by 2025.

50 These two options are shown 

in the table and chart below, along with the 2014LTRA reference case (total on-peak contribution for all coal-fired units in 

the United States).

Coal Projections: 2014LTRA Reference Case & EPA Clean Power Plan Assumptions

NERC 2014LTRA Reference Case - Total On-Peak Capacity (GW) 2016 2018 2020 2025*

Total Coal (Existing-Certain and Tier 1 Capacity Additions) 271.8 266.4 264.9 261.3

EPA Analysis of the Proposed Clean Power Plan - Total Coal Generating Capacity (GW) 2016 2018 2020 2025

Base Case 244.6 243.3 243.6 243.3

Option 1 (Regional Implementation) 217.5 207.8 198.0 197.2

Option 1 (State Implementation) 219.7 210.4 195.1 193.1

Option 2 (Regional Implementation) 225.0 217.3 214.3 214.3

Option 2 (State Implementation) 227.8 219.6 210.6 210.6

EPA Assumed Coal Reduction Beyond NERC 2014LTRA Reference Case (GW) 2016 2018 2020 2025

Base Case 27.2 23.1 21.3 18.0

Option 1 (Regional Implementation) 54.3 58.6 66.9 64.1

Option 1 (State Implementation) 52.1 56.0 69.8 68.2

Option 2 (Regional Implementation) 46.8 49.1 50.6 47.0

Option 2 (State Implementation) 44.0 46.8 54.3 50.7

*The 2014LTRA Reference Case includes data projections through 2024. 2024 projections were applied for 2025.

Ongoing Coal Retirements Contribute to Increased Dependence on Natural Gas

The EPA’s proposed Clean Power Plan will accelerate the shift in the generation mix from coal to natural gas. The EPA projects 

that the natural gas market portion of total U.S. power generation will grow from 29 percent (energy) in 2013 to 33–34 

percent between 2020 and 2030. A recent study conducted by Energy Ventures Analysis (EVA) indicates that natural gas 

generation will increase by an additional 400–450 TWh/year due to impacts of the proposed Clean Power Plan. This will result 

 

50 Regulatory Impacts Analysis for the Proposed Carbon Pollution Guidelines for Existing Power Plants and Emission Standards for Modified and 

Reconstructed Power Plants (June 2014) and supporting IPM Model documentation and data.

190

200

210

220

230

240

250

260

270

280

290

300

310

2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

Gigawatts

2014LTRA Reference Case* EPA Base Case

 Option 1 (State Implementation) Option 2 (Regional Implementation)
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

14

in an increase in the contribution of gas-fired generation in the energy market to a share of 35 percent in 2020, 39 percent in 

2030, and 49 percent in 2040.

51

With this shift toward more natural gas consumption in the power sector, the power industry will become increasingly 

vulnerable to risks from natural gas supply and transportation issues. Impacts due to extreme conditions should be integrated 

in planning scenarios to ensure a suitable generating fleet is available to maintain BPS reliability. Adverse winter weather,

such as the 2014 polar vortex, provided an example of the potential impacts to supply and transportation.

52 While several gas 

pipeline construction projects are underway to address deliverability issues in the Northeast, the shift toward additional 

natural gas consumption, as outlined in the proposed Clean Power Plan, would create additional pipeline needs. Sufficient 

lead times (more than three years) will be needed to plan and build new pipelines. This calls for a careful and deliberate 

review of the way in which natural gas is currently delivered and used by the electricity industry, so adjustments can be made

to support enhanced reliability of both the gas and electric systems. 

Increases in Variable Generation Are Creating Operational and Planning Challenges

The EPA Clean Power Program would provide states and developers additional incentives to rapidly expand their non-hydro 

renewable capacity to displace existing coal generation. The incremental increases in renewable generation would consist 

primarily of new wind and solar capacity.

To support such variable generating capacity increases, the power industry would need to invest heavily to expand 

transmission capacity to access more remote areas with high-quality wind resources. This further highlights the need for a 

resource mix with sufficient essential reliability services53 that support integration and reliable operation. Given the natural 

wind variability in remote locations, these incremental wind project resources would have relatively low capacity factors that 

would require substantial new transmission. 

Large penetration of VERs will also require maintaining a sufficient amount of reactive support, and ramping capability. More 

frequent ramping needed to provide this capability could increase cycling on conventional generation. This could contribute 

to increased maintenance hours and/or higher forced outage rates, potentially increasing the reserve requirements. Storage 

technologies can also support ramping needs and allow VERs to be more easily dispatched. While large-scale energy storage 

is not yet commercially viable,

54 the development of these technologies will enhance the industry’s ability to balance load 

and resources as more VERs are added to the system.

Based on industry studies and prior NERC assessments,

55 as the penetration of variable generation increases, maintaining 

system voltage stability can become more challenging. Additional studies will be needed to further understand potential 

challenges that may indirectly result from the proposed Clean Power Plan. Additional information on the integration of VERs

is included in the next section of this report.

Higher Retail Electricity Prices Could Cause a Sharp Increase in Distributed Energy Resources (DERs)

The EPA projects that retail electricity prices will increase by $1/MWh to $18/MWh under the Clean Power Plan56 resulting 

from a combination of higher natural gas prices and the implementation of new carbon penalties on impacted fossil-fired 

 

51 Energy Ventures Analysis: FuelCast – The Long-Term Outlook 2014, October 2014. Some information and analysis of the proposed CPP was performed by 

Energy Ventures Analysis, Inc. (EVA) and provided to NERC in September 2014 for use in this assessment.

52 NERC Polar Vortex Review (September 2014).

53 For additional information, see the NERC Essential Reliability Services Task Force.

54 Pumped storage offers tremendous ramping capabilities to the BPS; however, increases in this technology are not likely, due to land restrictions, 

permitting limitations, and environmental opposition. Less than 1 GW of new pumped storage capacity is projected over the next 10 years.

55 NERC-CAISO Joint Report: Maintaining Bulk Power System Reliability While Integrating Variable Energy Resources – CAISO Approach; other industry 

reports include those developed by the Integration of Variable Generation Task Force (IVGTF); Integrating Variable Renewable Energy in Electric Power 

Markets: Best Practices from International Experience (Appendix D).

56 Regulatory Impacts Analysis for the Proposed Carbon Pollution Guidelines for Existing Power Plants and Emission Standards for Modified and 

Reconstructed Power Plants (June 2014) and supporting IPM Model documentation and data.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

15

generators.57 As retail power prices rise, some existing customers may resort to the installation of renewable DERs, when 

economically advantageous—especially in locations with prominent solar and wind resources. Depending on the price 

advantage, the market penetration of DERs could be substantial, creating potential reliability impacts for grid operators that 

don’t have direct control of these resources. In some cases, resources without the direct control of the System Operator fall 

outside the jurisdiction of state utility regulators. A potential risk in additional DERs is the temporary displacement of utilityprovided service, which could create additional planning challenges, considering utilities must act as a secondary supplier of 

electricity. This is particularly the case during periods when variable DERs are experiencing high levels of intermittency. This 

issue does not exist for utility-scale wind energy, which offers ride-through capabilities and other essential reliability services.

Generation variability over different periods(seconds, minutes, hours) and the uncertainty associated with forecasting errors 

are operational characteristics of wind and solar resources. Similarly, large onsets of non-dispatchable resources have been 

shown to create the potential for operational challenges in California (particularly for solar),58 as well as Germany (particularly 

for wind). Additional information on DERs is included in the Other Reliability Issues section of this report.

EPA’s Assumed Substantial Increases in Energy Efficiency Programs Exceed Recent Trends and Projections

The EPA assumes up to a 1.5 percent annual retail sales goal for its incremental growth in energy efficiency savings in its rate 

calculation for best practices by state that will be triggered by the carbon regulation. The EPA assumes that the states and 

industry would rapidly expand energy efficiency savings programs from 22 TWh/year in 2012, to 108 TWh/year in 2020, and 

reach 380 TWh/year by 2029. With such aggressive energy efficiency expansion, the EPA assumes that energy efficiency will 

grow faster than electricity demand, with total electricity demand shrinking beyond 2020. The implications of this assumption

are complex. If the EPA-assumed energy efficiency growth rates cannot be attained, additional carbon reduction measures 

would be required, primarily through reduced fossil-fired generation in applicable states. More low-emitting and/or new 

generating capacity (not regulated under EPA Clean Power Plan) would need to be built. Construction of new replacement 

capacity would take time to plan, permit, finance, and build. If these needs are not identified at an early enough stage, either 

grid reliability or state CO2 emission goals could be compromised.

NERC collects on-peak energy efficiency data with reductions that are already reflected in the load forecasts for each 

Assessment Area. Based on the EPA’s projections for energy efficiency growth, a 1.5 percent annual increase is substantially 

above what has been examined in current and prior LTRA reference cases. Projected (on-peak) annual energy efficiency

growth as a portion of Total Internal Demand since 2011 has ranged from only 0.12 to 0.15 percent, as shown in the table 

below. 

2011-2014 LTRA Energy Efficiency Growth

LTRA

10-Year Growth of 

Energy Efficiency (%)

Portion of Total Internal Demand (%) Annual Growth in Relation

Year 1 Year 10 to Total Internal Demand (%)

2011 10.7 0.59 1.63 0.12

2012 12.2 0.72 1.88 0.13

2013 11.6 0.92 2.02 0.12

2014 13.4 0.87 2.25 0.15

 

57 According to EIA’s 2014 Annual Energy Outlook, closing coal plants will drive up natural gas prices by 150 percent over 2012 levels by 2040. This cost 

increase will cause electricity prices to jump 7 percent by 2025 and 22 percent by 2040. This is because natural gas prices are a key determinant of 

wholesale electricity prices, which in turn are a significant component of retail electricity prices. Accordingly, the cases with the highest delivered natural 

gas prices also show the highest retail electricity prices.

58 NERC-CAISO Joint Report: Maintaining Bulk Power System Reliability While Integrating Variable Energy Resources – CAISO Approach; other industry 

reports include those developed by the Integration of Variable Generation Task Force (IVGTF); Integrating Variable Renewable Energy in Electric Power 

Markets: Best Practices from International Experience (Appendix D).
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

16

Transmission Considerations

The EPA assumes that adequate transmission capacity will be available to deliver any resources located in or transferred to a 

given area.

59 However, given the significant changes occurring in the resource mix, it is likely that additional new transmission, 

or enhancements to existing transmission, will be needed in some areas, particularly those with existing and planned resource 

additions that include higher penetration of renewable generation. Additionally, as replacement generation is constructed, 

new transmission will be needed to interconnect this capacity. The designing, engineering, and contracting requirements for 

these new lines, as well as siting, permitting, and various federal, state, provincial, and municipal approvals often require 

more than five years to complete. Thus, industry should consider the long lead times required for new transmission. 

 

59 Regulatory Impacts Analysis for the Proposed Carbon Pollution Guidelines for Existing Power Plants and Emission Standards for Modified and 

Reconstructed Power Plants (June 2014) and supporting IPM Model documentation and data.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

17

Key Reliability Finding #2

Environmental Regulations Create Uncertainty and Require Assessment

Recommendations and Next Steps

NERC Board of Trustees Endorsed Assessment Plan: The NERC Board of Trustees endorsed a plan to review and assess the reliability 

impacts of the EPA proposal at its August 2014 Board meeting. This plan included a preliminary review of the assumptions and 

potential major reliability impacts resulting from the implementation of the EPA’s notice of proposed rulemaking under Section 

111(d). With the EPA scheduled to finalize its rule by June 2015, NERC will develop a reliability assessment that will focus on a more 

detailed analysis of the respective reliability impacts.

Phased Approach: An initial review of the EPA’s proposed Clean Power Plan is included within this assessment. NERC will release an 

initial high-level reliability review based on the assumptions used in the proposed rule in November 2014. Subsequently, NERC will 

conduct a special reliability assessment to be released in phases. The first phase, expected to be released in April 2015, will be a 

detailed assessment to evaluate generation and transmission adequacy and leverage industry studies, prior to rule finalization. The 

second phase, with a target release date in December 2015, will incorporate the final rule prior to states submitting implementation 

plans to the EPA in June 2016. Additionally, a Phase III approach is tentatively planned for December 2016, which will examine 

finalized state implementation plans. A proposed timeline of these activities is provided below. Additionally, NERC will address 

reliability constraints identified and incorporated into transmission expansion plans for future long-term and seasonal assessments.

The NERC Steering Groups and Ongoing Stakeholder Involvement: Industry members should participate in steering groups to 

provide ongoing input on the EPA’s proposed Clean Power Plan. NERC will also utilize its stakeholder process through the MRC and 

PC to solicit input and collaborate to identify and address potential reliability impacts due to the proposed rule.

November 

2014

April

2015

December

2016

December

2015

Special Reliability 

Assessment: 

Phase III

• Placeholder for assessment 

completed once a selection 

of SIPs are developed 

(some single state, some 

multi-state)

Initial Reliability Review 

of EPA’s Proposed Clean 

Power Plan

• High-level reliability 

considerations

• Assessment of EPA’s 

rule assumptions

Special Reliability Assessment: 

Phase II

• Additional assessment of 

emerging SIPs

• Reflects final rule

• Conventional reliability 

assessment based on known 

requirements 

• Complete before states 

submit plans (SIPs)

Special Reliability Assessment:

Phase I

• Evaluation of generation and 

transmission adequacy; 

• Sensitivity analysis used to provide 

range of potential outcomes

• Leverage industry studies and 

initiatives
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

18

3. A Changing Resource Mix Requires New Approaches for Assessing Reliability

North America’s resource mix is undergoing a significant transformation at an accelerated pace with ongoing retirements of 

fossil-fired and nuclear capacity and growth in natural gas, wind, and solar resources. This shift is caused by several drivers,

primarily existing and proposed federal, state, and provincial environmental regulations. Other drivers include lower natural 

gas prices due to abundant supply, along with policies incentivizing the movement from conventional energy resources

toward ongoing integration of both distributed and utility-scale renewable resources. The convergence of these resource mix 

changes is directly impacting the behavior of the North American BPS. These developments will have important implications 

on industry planning and operations, as well as how NERC assesses reliability.

NERC-Wide Tier 1 and 2 Additions (2015–2024)60

Increased Dependence on Natural Gas Due to Ongoing Decline in Coal-Fired Capacity

Natural-gas-fired capacity continues to be the replacement capacity of choice for resource planners as other fossil-fired units 

are retired. This trend is expected to continue with the addition of 44.6 GW of gas-fired capacity, accounting for nearly half 

of all Tier 1 nameplate capacity additions during the next decade. By 2024, natural gas will contribute 42 percent of the onpeak resource mix, compared to 40 percent in 2015.

A variety of drivers makes natural-gas-fired capacity an attractive resource. Most impactful is the price of natural gas, which

is projected to remain low (relative to other fuels), with abundant supplies from shale formations throughout North 

America.61 Additionally, the emergence of more efficient NGCC generating technology requires lower engineering, 

procurement, and construction costs. The shorter build times for NGCC plants can help resource planners avoid procurement 

challenges that exist with other options. Perhaps the most impactful benefit is the environmental advantage of lower carbon 

emissions when compared to coal-fired power plants without carbon capture and sequestration. Finally, natural-gas-fired 

units can provide System Operators with needed flexibility to address additional variability as VERs account for a larger 

portion of the resource mix in certain areas.

 

60 Tier 1 includes capacity additions that are either under construction or have received approved planning requirements. Tier 2 includes capacity additions 

that have requested but not received approval for planning requirements.

61 EIA Annual Energy Outlook 2014. 

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140

Geothermal

Pumped Storage

Biomass

Coal

Solar

Hydro

Nuclear

Wind

Natural Gas

Gigawatts

Tier 1 Tier 2
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

19

2008–2014 LTRA 10-Year Net Change Indicates Ongoing Declines in Coal and Growth in Gas

As planners rely more on natural gas for both baseload and on-peak capacity, it is important to also examine potential risks 

associated with increased dependence on a single fuel type. Currently, natural-gas-fired capacity accounts for large portions 

of both the total and on-peak generation mix in several Assessment Areas for both existing capacity and planned additions.

Assessment Areas with Natural-Gas-Fired Capacity Accounting for Over One-Third of Existing Nameplate Capacity

Nameplate Capacity (GW) On-Peak Capacity (GW) 10-Year Nameplate Capacity Additions (GW)

Assessment Area Gas-Fired Portion of Total Gas-Fired Portion of Total Tier 1 Tier 2 Tier 3

FRCC 40.2 64% 33.9 63% 10.1 0.0 0.0 

MISO 69.0 39% 58.7 41% 2.8 0.0 10.0 

NPCC-New England 18.6 54% 13.3 43% 1.1 3.3 0.0 

NPCC-New York 21.0 55% 14.2 40% 0.0 3.5 0.0 

PJM 80.0 43% 56.5 32% 10.0 47.5 0.0 

SERC-SE 31.2 47% 28.4 46% 0.0 0.0 2.6 

SPP 32.3 40% 30.2 47% 1.1 0.7 5.7 

TRE-ERCOT 48.4 54% 45.2 63% 4.9 21.5 0.0 

WECC-CA/MX 47.7 61% 43.9 70% 5.5 6.2 0.9 

WECC-RMRG 7.2 36% 6.2 41% 1.2 0.0 0.0 

WECC-SRSG 19.5 47% 16.3 50% 0.6 1.0 3.0 

Higher Reliance on Natural Gas Further Exposes BPS to Impacts from Fuel Transportation Disruptions

The electricity sector’s growing reliance on natural gas raises concerns regarding the electricity infrastructure’s ability to 

maintain BPS reliability when facing constraints on the natural gas pipeline system. The extent of these concerns from 

Independent System Operators (ISOs), Regional Transmission Organizations (RTOs), electricity market participants, industrial 

consumers, national and regional regulatory bodies, and other government officials varies throughout North America; 

however, concerns are most acute in areas where power generators rely on non-Firm pipeline transportation as natural gas 

used for power generation continues to rapidly grow.

Natural gas supply and transportation infrastructure adequacy concerns, particularly in certain parts of North America, are 

causing NERC, industry, and policymakers to refocus attention on the interdependency between natural gas and electricity 

industries. System Operators and resource planners continue to make considerable progress to consider fuel supply and 

transportation adequacy as a formal part of reliability assessment.

Under average annual operating conditions, most pipelines have some level of capacity that is not used by Firm customers 

and is therefore available for non-Firm (interruptible) loads, including natural gas generators with non-Firm contracts. If the 

requirements for non-Firm deliveries are communicated to the pipeline within the nomination cycle timeline, the pipeline 

can use facilities to enable delivery of natural gas requested up to its allowed physical capabilities. This is the normal 

procedure for interruptible transportation service or capacity release from Firm shippers. In some power markets or areas

225

250

275

300

325

350

375

400

425

450

475

2008 2009 2010 2011 2012 2013 2014

Gigawatts

Gas (Year 1) Gas (Year 10) Coal (Year 1) Coal (Year 10)
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

20

where there is excess natural gas pipeline capacity available, these low-capacity-factor units can rely upon interruptible 

service with a reasonable degree of certainty that service will be available.

However, as growth in natural gas demand increases, pipeline transportation constraints will have a greater impact on 

natural-gas-fired generation, making units with non-Firm service vulnerable to more frequent interruption. If a generator 

served by interruptible service has no secondary fuel source, then that generating capacity could be unavailable during peak 

periods. While coordination efforts between the gas and electric industries continue to improve, the potential still exists for 

a mismatch between the availability of natural gas delivery and natural gas demand for electricity generation. This can be 

particularly challenging in areas where a significant amount of the capacity—or more importantly, reserve capacity—is 

susceptible to natural gas transportation interruptions, potentially resulting in more frequent generator outages.

What Does the 2014 Polar Vortex Tell Us about the Future?

As more generating capacity is natural gas fired, additional 

assessment of Firm pipeline transportation is needed to 

ensure sufficient gas is available during both normal 

operation and periods of high stress, as exemplified by the 

polar vortex event.62

Overdependence on a single fuel type increases the risk of 

common-mode disruptions as experienced during recent 

extreme weather events. Disruptions in natural gas 

transportation to power generators have prompted the gas 

and electric industries to further examine reliability 

implications associated with increasing natural-gas-fired 

generation. 

As highlighted in this assessment, most new capacity 

additions are natural gas fired. Over the past two years, both 

industries have made significant progress to better link the 

operations of these vastly different industries. 

The gas and electric industries operate under different 

regulatory structures and rules that affect how infrastructure 

is planned, built, maintained, and ultimately operated. As the 

dependence on natural-gas-fired generation increases in 

North America, the natural gas and electricity industries 

continue coordination efforts. The relationship between 

natural-gas-fired generation availability and low 

temperatures further challenges the industry’s ability to 

manage extreme weather conditions, particularly when 

conditions affect a wide area and there is less support 

available from within an interconnection. These extreme 

weather events should serve as early indicators of more 

frequent impacts if natural gas supply and transportation is 

outstripped by the demand from new natural-gas-fired units 

continue to rely on interruptible gas.

 

62 For additional information, see NERC’s Polar Vortex Review (September 2014).

2014 Polar Vortex

NERC Scenario: Considerations for Long-Term Planning

The 2014 polar vortex, impacting a majority of the midwestern

and northeastern United States and southern Canada, tested 

the resilience of the North American BPS. This event served as 

an example of how extended periods of cold temperatures have

direct impacts on fuel availability, especially for natural-gasfired capacity. Higher-than-expected forced outages were 

observed during the polar vortex, particularly for natural-gasfired generators, as well as higher-than-forecast peak demand. 

The following impacts were caused by fuel delivery challenges 

and extended periods of low temperatures:

Fuel Delivery

 Natural gas interruptions: supply injection, compressor 

outages, and one pipeline explosion

 Oil delivery problems

 Inability to procure gas

 Fuel oil gelling 

Low Temperatures

 Low temperature limits for wind turbines

 Icing on hydro units

 Failed auxiliary equipment

 Stress of extended run times

 Frozen instrumentation (drum level sensors, control 

valves, and flow and pressure sensors

To examine the potential impacts of a similar event in the 

future, NERC ran scenarios on select Assessment Areas (SERC-E, 

PJM, MISO, and TRE-ERCOT) that experienced significant loss of 

generation during the 2014 polar vortex event. Actual forced 

outage data were applied as derates to existing and projected 

(Tier 1) capacity projections using the 2014LTRA reference case. 

Load was assumed to be consistent with the extreme loads that 

were observed.

Based on this NERC scenario, projected reserve margins 

combined with the projected increased dependence on natural 

gas will increase the adverse impacts to BPS reliability if similar 

extreme weather events occur in the future.

The complete scenario is included as Appendix III.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

21

Summer Considerations for Natural Gas

While gas-electric supply and transportation issues are especially important during the winter season, the summer season 

presents a separate set of potential reliability impacts that requires ongoing attention. Specifically, the electricity industry 

must be aware of pipeline maintenance schedules and promote ongoing coordination to ensure individual generators do not 

face supply shortages—principally those that can be resolved through coordination—during peak conditions.

Recent and Planned Industry Initiatives to Address Increasing Dependence on Natural Gas for Electric Power

The gas and electric industries have recently made substantial progress to enhance coordination and develop new strategies 

to address system reliability due to fuel supply and transportation concerns. These efforts helped to reduce the severity of 

impacts experienced during the 2014 polar vortex event. These developments are presented below for Assessment Areas 

with gas-fired capacity that accounts for over one-third of their existing generation mix.

FRCC

FRCC performs an annual review of natural gasinfrastructure and maintains a Generating Capacity Shortage Plan that outlines 

communications, environmental, and political procedures in the event of a fuel shortage.

MISO

MISO developed procedures to facilitate communication between power plant operators and natural gas transportation 

service providers under which MISO is notified of all operational flow orders and other information to raise awareness of 

potential issues that may impact generation capacity.

The MISO Electric and Natural Gas Coordination Task Force (ENGCTF)63 has also developed comprehensive examinations of 

three key gas-electric coordination challenges: (1) addressing gas-electric scheduling and market timeline misalignment, (2) 

capturing fuel risk in the resource adequacy construct, and (3) strengthening gas-electric communications. Recent ENGCTF 

developments include:

 Natural gas infrastructure displays in control rooms

 An online platform to consolidate natural gas pipeline operational flow orders and critical notices

 A database linking natural gas generators to their fuel supply sources, as well as to operational flow orders and 

critical notices

 A preliminary LOLE study, focusing on the concern of increased probability of load loss resulting from gas-fired 

generators’ inability to access fuel during peak energy operating conditions

Additional topics are currently being explored by the ENGCTF:

 Polar vortex experiences (natural gas availability and enhanced RTO/pipeline communications)

 Potential competition between generator demand and upcoming gas storage injection

 Process and timeline considerations for natural gas infrastructure build-out

NPCC-New England

After the “cold-snap” of January 2004, ISO New England and the Northeast Gas Association (NGA) established the ElectricGas Operations Committee (EGOC),64 which meets quarterly to discuss issues common to both gas and electric sectors. ISONE also participates in the following activities: (1) coordinated studies with NYISO, PJM, Ontario, TVA, and MISO; (2) multiregional static/transient hydraulic natural gas analyses; (3) NERC/NPCC natural gas assessments; and (4) the Eastern 

Interconnection Planning Collaborative (EIPC) Gas-Electric System Interface Study.65 ISO-NE has also performed internal 

studies to evaluate regional pipeline capacity and local distribution company (LDC) operations, dual-fuel capability, 

environmental issues of generators, liquid fuel availability, and regional storage capability. Recent operational changes

include: (1) moving forward the scheduled timelines of participant bid submittals; (2) processing and publishing the day-

 

63 MISO Electric and Natural Gas Coordination Task Force. 

64 ISO-New England Electric/Gas Operations Committee. 

65 EIPC Gas-Electric Study. 
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

22

ahead market results; (3) implementing a participant re-offer period; and (4) completing the resource adequacy assessment 

in order to provide startup notification to long-lead time resources that are needed to operate the next day to ensure system 

or sub-area reliability or transmission security.

NPCC-New York

NPCC-New York developed a cold weather procedure to monitor gas nominations, oil inventories, and expected oil 

replenishment schedules for all dual-fuel, gas-fired, and oil-fired generators prior to each cold day. NPCC-New York also 

conducts an annual survey each fall that requests information on gas transportation arrangements, oil inventory, and oil 

replenishment capability from the same generators and uses this fuel information to monitor a generator’s capability to meet 

the day-ahead electricity schedules. NYISO is also working to increase awareness of the gas system in the control room in 

order to provide greater visibility into gas pipeline system conditions and generator fuel capability. This includes the ability 

to monitor the actual fuel capability of units. This will provide additional real-time information to help operations maintain 

electric system reliability—particularly during periods of the more restrictive hourly operational flow orders. Finally, NYISO is 

coordinating efforts with the interstate, intrastate, and LDC pipelines to incorporate gas pipeline outage scheduling with 

electric system outage scheduling.

PJM

PJM recently formed the Gas Electric Senior Task Force (GESTF)66 to help identify and examine gas-electric issues and develop 

solutions. PJM continues to participate in both the EIPC Gas Electric System Interface study and the North American Energy 

Standards Board (NAESB) process to explore consensus development with the gas industry on market coordination issues.

PJM also coordinates with other ISO/RTOs to improve and standardize communication practices with the gas pipelines. 

Increased coordination between gas pipelines and generator owners is a priority to ensure sufficient availability of resources, 

particularly during the 2014 polar vortex. PJM is addressing differences between the timing of generators’ required natural 

gas purchase commitments and PJM’s day-ahead energy market commitment.

SERC

In SERC, many plants are covered by tolling agreements that include Firm pipeline transportation. The entity identified in the 

tolling agreement performs planning and operational procedures and coordination activities. Several entities individually 

perform these activities. Entities also coordinate activities surrounding facility startups and shutdowns, pipeline warnings,

and pipeline outages or restrictions. Larger entities in SERC have a centralized unit commitment planning function that 

includes gas trading and power trading functions, as well as the generation dispatch function. Entities are also communicating

with the pipeline operators to determine any potential issues in the development of contingency plans as required, including

the acquisition of additional Firm transportation and storage capacity to meet projected demands. 

SERC entities continue to work closely with FERC and NAESB from both a policy and business standards perspective on gaselectric coordination. Larger entities address gas supply and transportation issues during extreme weather events through 

conference calls. These calls are held to coordinate real-time contingency plans with key stakeholders including generator 

operators, transmission operators, and fuel providers. Firm natural gas pipeline agreements, Firm delivered fuel agreements, 

investments in gas storage, enabling agreements with multiple gas suppliers, and back-up fuel sources are all in place to 

ensure reliable fuel delivery in extreme weather events. Many entities within SERC use natural gas only for boiler startup, 

typically only a few times per year or for any forced outages that may occur.

SPP

In 2013, SPP formed the Gas Electric Coordination Task Force (GECTF)67 to provide a greater operational awareness of the gas 

fuel supply. The GECTF recently created the Weather Operational Plan to improve communication between major gas 

suppliers and SPP grid operations (this plan was executed four times during the 2013–2014 winter season).

 

66 PJM Gas Electric Senior Task Force. 

67 SPP Gas Electric Coordination Task Force. 
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

23

TRE-ERCOT

In ERCOT, the Black Start Working Group (BSWG)68 coordinates efforts with the natural gas industry (the supply of gas to 

blackstart units in ERCOT is particularly important in the event of a total system restoration, which has been made evident 

after an examination of ERCOT’s restoration system plans). The BSWG (including major gas pipeline operators and the electric 

transmission operators within ERCOT) is working to identify priority loads that need to be restored for gas facilities to continue 

to transport gas in the event of a total system restoration. Currently, the transmission operators are working to include these 

priority loads in their respective restoration plans. Initiatives continue with major pipelines to improve communications 

between the gas and electric industries and develop confidentiality agreements with involved entities. This will allow for the 

exchange of operational information to facilitate improved real-time decision making by informing parties of unit 

commitment and overall operations in times of stress on either system.

WECC

WECC subregions are involved in the FERC NOPR (RM14-2-000) process to better coordinate the scheduling of natural gas 

and electricity markets in light of increased reliance on natural gas for electric generation. During extreme weather events,

daily calls occur between the generating resources and gas supply and transportation companies. These calls are done so that 

the generating units know the status of both gas supply and deliverability with the end goal of maintaining overall reliable 

operations of the BPS.

 

68 ERCOT Black Start Working Group. 
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

24

Ongoing Growth in Wind and Solar Resources Requires More System Flexibility

NERC-wide, 32 continental states and the District of Columbia have implemented renewable portfolio standards (RPSs),

69

with similar policies in several Canadian provinces. These policies mandate or otherwise establish goals for electricity 

producers to supply a specified portion of electricity from eligible renewable energy sources (typically wind, solar, biomass, 

geothermal, and some hydroelectric).70 Additionally, greenhouse gas emission regulations (notably CO2) and continually 

declining costs of renewable resources further incentivize construction of renewable resources throughout North America. 

The continued growth of renewable generation offers benefits such as newer generation resources, fuel diversification, and 

greenhouse gas reductions. However, to maintain BPS reliability, challenges presented by additional variable resources as a 

result of renewable energy policies need to be properly addressed.

NERC-Wide 10-Year Additions of Wind and Solar

Wind and solar will account for a large portion of Tier 1 nameplate capacity additions during the next decade, with 29 GW 

(1.7 GW on-peak) and 4.4 GW (3.2 GW on-peak), respectively. When examining Tier 1 and 2 capacity additions, up to 74.2 

GW of wind additions and 14.3 GW of solar additions are projected by 2024. While VERs account for a growing portion of the 

total energy contribution, resource planners are relying on smaller amounts of wind and solar when examining resource 

availability during the hours of peak demand. 

Nameplate additions of over 11 GW were projected in the 

2013LTRA, primarily in the southeastern subregions of the 

WECC Interconnection. In the 2014LTRA reference case, 3.3 

GW of Tier 1 and 8.5 GW of Tier 2 additions are planned by 

2024.

High levels of wind and solar resources can create 

challenges for grid operators due to the inherent swings, or 

ramps, in power output. In certain Assessment Areas—

particularly WECC-CA/MX and WECC-RMRG—the on-peak 

portion of VERs is projected to supply up to 9.7 and 6.7 

percent of the 2015 Total Internal Demand. System 

planners in areas with higher concentrations of VERs must 

accommodate added variability by increasing the amount 

of available regulating reserves and carrying additional 

operating reserves. Because weather plays a key factor in 

determining wind and solar output, enhancing regional 

forecasting systems can provide more accurate generation 

projections. Other methods include curtailment and 

limitation procedures used when generation exceeds the 

 

69 Also referred to as renewable electricity standard or a renewable energy standard.

70 Database of State Incentives for Renewables & Efficiency.

0 10 20 30 40 50 60 70 80

Solar Tier 1 & Tier 2

Wind Tier 1 & Tier 2

Solar Tier 1

Wind Tier 1

Gigawatts

On-Peak Wind Derated Wind On-Peak Solar Derated Solar

Transmission Considerations with Additional VERs

Reliably integrating the projected 30.8 GW of additional wind 

and solar resources will require additional transmission. VERs 

are often built in parts of North America that are distant from 

the point of interconnection to the transmission system. In 

many cases, the location of these variable resources only meets 

the minimum voltage support requirements. According to the 

2014LTRA reference case, 16 percent of new transmission 

projects (under construction, planned, or conceptual) identify 

variable resource integration as a primary driver.

New Transmission Project Drivers

Other 

Drivers

84%

Variable 

Integration

16%
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

25

available regulating resources. In this respect, operating criteria, forecasting, commitment, scheduling, dispatch and 

balancing practices, procedures, and tools must be enhanced to assist operators in maintaining BPS reliability.

Several Assessment Areas with High Existing VER Penetration (Nameplate) as a Portion of the 2015 Generation Mix

Assessment Area

Existing 

Nameplate 

(MW)

Existing On-Peak 

Contribution 

(MW)

Existing On-Peak 

Contribution (%)

Existing 

Nameplate 

(MW)

Existing On-Peak 

Contribution 

(MW)

Existing On-Peak 

Contribution (%)

FRCC 0 0 0.0% 56 7 0.0%

MISO 16,383 1,060 6.5% 0 0 0.0%

MRO-Manitoba Hydro 259 0 0.0% 0 0 0.0%

MRO-MAPP 1,114 260 23.6% 0 0 0.0%

MRO-SaskPower 198 40 19.8% 0 0 0.0%

NPCC-Maritimes 1,101 271 24.7% 0 0 0.0%

NPCC-New England 788 101 12.7% 0 99 0.0%

NPCC-New York 1,708 249 14.6% 212 11 5.2%

NPCC-Ontario 1,695 270 15.9% 32 0 0.0%

NPCC-Québec 2,400 0 0.0% 0 689 0.0%

PJM 5,824 908 15.7% 238 92 38.4%

SERC-E 0 0 0.0% 29 28 98.9%

SERC-N 179 28 15.3% 0 0 0.0%

SERC-SE 0 0 0.0% 4 4 100.0%

SPP 6986 242 3.5% 50 5 10.0%

TRE-ERCOT 11,093 996 8.7% 123 123 100.0%

WECC-CAMX 6,422 2,345 36.6% 4,297 1,565 36.4%

WECC-NWPP 11,167 3,258 29.1% 378 0 0.0%

WECC-RMRG 2,420 718 29.9% 127 54 42.8%

WECC-SRSG 789 155 19.3% 1,004 361 35.9%

NERC TOTAL 70,540 10,901 15.5% 6,551 3,037 46.4%
Key Reliability Findings

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26

Planning Considerations for VERs in Long-Term Planning

Most Assessment Areas account for a small portion the total nameplate capacity of wind and solar resources when planning. 

MISO and ERCOT, for example, use a probabilistic basis for determining this factor. The Effective Load Carrying Capability 

(ELCC) establishes a percentage of total nameplate wind or solar capacity that is relied on for planning purposes. ERCOT 

currently employs an ELCC of 8.7 percent for all wind resources, meaning that 8.7 percent of the approximately 11 GW of 

wind is applied toward the Existing-Certain capacity category and included in the Anticipated Resources and Reserve Margin.

According to the 2014LTRA reference case, NERC-wide Tier 1 nameplate wind and solar additions amount to 29 GW and 4 

GW, respectively, during the next decade. However, the on-peak contribution will increase by only 1.4 GW for wind and 0.4 

GW for solar, based on current methods and assumptions values for planning variable capacity additions.

NERC-Wide 10-Year Wind (Left) and Solar (Right) Tier 1 Capacity Additions

0

3

6

9

12

15

18

21

24

27

30

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

On-Peak Derate

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

On-Peak Derate
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

27

Key Reliability Finding #3

A Changing Resource Mix Requires New Approaches for Assessing Reliability

Observations

Effects of environmental regulations, a less diverse resource mix, and an increase in VERs will result in greater dependence on natural 

gas for electric power generation in the future. With the demand for natural gas for power generation increasing, greater 

engagement among both sectors is needed to ensure sufficient resource allocation for reliable operation of the electric system.

Recommendations

Expanded Gas-Electric Planning and Coordination: Thorough harmonized efforts between electric and gas sectors are needed in 

order to meet future infrastructure needs to supply and transport fuel. System planners in certain areas (with high levels of naturalgas-fired resources) should examine system reliability needs to determine if more Firm fuel transportation or units with dual-fuel 

capability are needed. Additionally, fuel availability and deliverability should be specifically considered and integrated into resource 

adequacy and other planning assessments.

Operational Coordination Strategies between Gas and Electric Industries: System Operators should develop or enhance 

coordination strategies to address potential fuel interruptions, especially prior to anticipated extreme weather events. Generator 

owners should consider securing on-site secondary fuel in the event that non-Firm gas service is curtailed.

Variable Energy Resource Considerations: Because each system within the North American BPS is unique, detailed studies and 

investigations must be completed to understand how changes to the resource mix in certain areas, particularly those with a large 

onset of VERs, will impact their systems, particularly essential reliability services. The Essential Reliability Services Task Force (ERSTF) 

recently developed a concept paper that examines three building blocks that system planners should consider for maintaining 

reliability in the ongoing shift to systems with more variable resources:

 Balance of Load and Resources: The BPS should be planned and operated with the continued ability to raise and lower 

generation or load automatically or manually under normal and post-contingency conditions (i.e., ramping capabilities).

 Voltage Support: This is required to maintain system level voltages on the BPS within established limits, under pre- and 

post-contingency situations, thus preventing voltage collapse or system instability.

 Frequency Support: This is required to maintain stable frequency on the synchronized BPS by employing automatic 

response functions of a resource in response to deviations from normal operating frequency.

Essential Reliability Services: NERC urges the continued efforts of the ERSTF to develop additional metrics for measuring the 

reliability impacts of a resource mix that is increasingly dependent on variable resources.

The Need for Flexibility: Based on previous NERC assessments and analyses, as the level of VERs increases, more flexibility will be 

needed from the system. In the past decade, manufacturers have made significant advancements in control methods that can make 

VER power output more responsive to grid-level controls, including frequency response and down regulation. Industry should 

continue to examine how wind and solar plants can contribute to frequency response and work toward interconnection 

requirements that ensure System Operators will continue to maintain essential reliability services.

The Need for New Reliability Assessment Approaches: As part of its assessment of long-term reliability, NERC should consider using 

new approaches to evaluate the changing behavior of the BPS. These additional approaches should consider ERS, probabilistic, and 

transmission adequacy assessments—in conjunction with the existing Reserve Margin metric—to address and evaluate potential 

reliability issues in the future. Additional detail on these efforts can be found in the next section.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

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New Approaches for Assessing Reliability

The North American generation mix is primarily comprised of conventional generation (hydroelectric, coal, petroleum, 

nuclear, and natural gas). With this generation mix, the use of a Reserve Margin continues to be an effective approach for 

assessing resource adequacy. Reserve Margins measure the amount of generation capacity available to meet expected 

demand during the planning horizon and have been a surrogate metric for examining and planning for resource adequacy 

and system reliability. Based on the premise of this metric, a system should be able to supply resources to meet the projected 

normal weather electricity demand (given some explicit 

amount of reserve capacity), with a high degree of certainty 

that the system can manage generator outages and modest 

deviations from the annual demand forecast. The Reference 

Margin Level guideline does not evaluate the effects of unit 

size or performance, the size of the system, or the strength 

of its interconnections in each Assessment Area. In North 

America, given the static measure of generation reliability, 

Reference Margin Levels are reviewed and, if necessary, 

revised as significant system changes occur.

The one-event-in-ten-year (0.1 events per year) LOLE is 

produced from this type of analysis. This industry guideline 

requires an electric system to maintain sufficient generation 

and Demand Response resources such that system peak 

load is likely to exceed available supply once in a ten-year 

period. Utilities, System Operators, and regulators across 

North America rely on variations of the one-event-in-tenyear guideline for ensuring and maintaining resource 

adequacy.

Although Reserve Margins offer insight into the relative ability of a system to serve load based on existing and planned 

resources, this metric does not fully capture important reliability attributes essential for ensuring BPS reliability. The

Reference Margin Level assumes that various types of operating reserves are available (e.g., regulating reserves, spinning 

reserves, non-spinning reserves, and load-following reserves) to balance load and supply in real time and enable System 

Operators to quickly and reliably respond to a system contingency.

71 In contrast to an operating reserve requirement, which 

applies during real-time system operations (irrespective of load levels or generator availability), the Reserve Margin metric is 

developed to ensure that sufficient resources are available to address reliability challenges due to differences between: (1) 

short-term or medium-term peak load forecasts (reflecting normal weather) and typical generation outages; and (2) actual 

peak loads (which can exceed reflected weather-related discrepancies in load) and spikes in generation outages.

In addition, the Reserve Margin metric assumes that generator fuel availability is not correlated with load levels or weather. 

However, recent extreme weather events have caused an increased number of forced outages due to fuel unavailability,

particularly natural gas. Assumptions of the Reserve Margin metric may be understating these risks. For VERs, a proxy for fuel 

availability is used to adjust installed or seasonally rated capacity values—with installed or nameplate capacity derated in 

Reserve Margin calculations. This approach fails to provide an evaluation of the reliability of VERs during off-peak hours or 

during extreme weather events.

 

71 Defined as a sudden failure of an electrical facility, such as a transmission line, breaker, transformer, or generation unit.

Current Reserve Margin Method

The Reserve Margin and LOLE statistics are related. As shown 

the example below, as the reserve margin decreases, the 

likelihood of a supply deficit—or "reliability event"—increases.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

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Essential Reliability Services

In June 2014, NERC commissioned ERSTF to reconcile a collection of analytical approaches for understanding potential 

reliability impacts as a result of increasing variable resources and how these impacts can affect system configuration, 

composition, operation and the need for increased ERSs. The ERSTF identified three reliability attributes or building blocks to 

help define ERSs. These services represent the operating characteristics and reliability functions that are vital to ensuring BPS 

reliability. The ERS building blocks have three components: (1) load and resource balance, (2) voltage support, and (3) 

frequency support. In order to maintain reliability, the BPS must maintain sufficient levels of ERSs. While ERSs are technology 

neutral and must be provided regardless of the resource mix composition, gaps in ERSs can lead to adverse impacts on 

reliability. ERSs can be addressed with appropriate policies and standards. 

While some VERs are capable of providing components of ERSs, the variability of these weather-dependent resources makes

them difficult for System Operators to depend on. One of the reliability concerns presented by higher percentages of variable 

resources is the displacement of resources that have the ability to arrest and stabilize system frequency following a grid 

disturbance or the sudden loss of a large generator. Photovoltaic solar resources offer no inertia or frequency response. Wind 

resources can offer inertia and frequency response, depending on the design attributes of a given wind plant. However, by 

causing conventional generators to have their output dispatched down, wind and solar generation can increase generator 

headroom and, therefore, the amount of total frequency response being provided. Other potential approaches include the

use of probabilistic methods to more accurately quantify the potential for challenges balancing resources with load.

Probabilistic Assessments

Reliability outcomes depend on a host of complex and interdependent factors, such as the projected resource mix, generator 

availability, and weather uncertainty. Evaluating these factors requires a probabilistic approach to provide a more robust 

understanding of resource adequacy. This requires statistically characterizing the following: (1) uncertainty in load forecasts;

(2) output of the generation fleet; (3) inclusion of variable resources; (4) availability of imports; and a number of other factors 

that may impact the ability of a system’s resources to contribute to reliability. Accordingly, NERC started conducting biannual

probabilistic assessments to supplement the Long-Term Reliability Assessment.

72 These supplemental reports are released 

on even years, typically in March, to provide a common set of probabilistic reliability indices and recommendations. 

Probabilistic metrics used in the assessment include: (1) annual Loss-of Load Hours (LOLH), (2) Expected Unserved Energy 

(EUE), and (3) Expected Unserved Energy as a percentage of Net Energy for Load (normalized EUE) for two common forecast 

years (year 2 and year 5 of the LTRA assessment projections). Scenario analysis is also performed to help identify sensitivities 

and off-normal circumstances.

Additional Consideration for Transmission Adequacy

Because of the downward trend in the Reserve Marginsfor several Assessment Areas, combined with ongoing changes to the 

characteristics of the system, resources planners should consider more comprehensive assessments of transfer capabilities 

with neighboring areas. These assessments should include future plans for resources and transmission, such as potential unit 

retirements and capacity additions, particularly for wind and solar. Integrating these plans into operations and planning 

models will yield more accurate powerflow and dynamic studies. The results of these improved studies should also be shared 

between neighboring systems.

New approaches for assessing reliability should include adequate collaboration between two or more BAs to support reliable 

BPS planning. Depending on the unique characteristics of each BA, transmission adequacy studies should include the 

following: (1) the use of powerflow models that contain a common economic generator dispatch that all parties accept; (2) 

the evaluation of non-BES elements that could potentially impact the BPS; and (3) the projection and evaluation of the 

potential system impacts from external contingencies on their systems. If contingencies are identified that would impact 

neighboring systems, the adequacy studies should be shared among all impacted parties.

 

72 The 2014 Probabilistic Assessment uses 2014LTRA reference case data. NERC’s Probabilistic Assessments are released biannually (even years).
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

30

Other Reliability Issues

In addition to the three key findings above, NERC also continues to examine the ongoing impacts of several other issues. 

NERC will continue to monitor these issues to determine if additional evaluation or special assessments are needed.

Load Forecasting Uncertainties

Despite slower load growth projections, the electric industry continues to face several challenges in forecasting electricity

demand. Specifically, conservation programs, smart grid technologies, and DERs have complicated traditional load forecasting 

methods that were traditionally functions of weather conditions, economic cycles, and population growth.

In addition to other variables, there is sufficient empirical evidence to suggest that correlations between load growth and 

economic outlook—a critical input for most load forecasts—have diminished. As new variables are introduced to load 

forecasting models, further analysis will be necessary to gain a better understanding of the actual impacts and appropriately 

integrate them into short‐ and long‐term load forecasting methods. New technologies, like advanced metering infrastructure, 

plug-in hybrid electric vehicles, and real‐time pricing, may provide better quality load data to utilities. However, in the near 

term (one-to-five years), these technologies may further contribute to the uncertainty, due to changing residential customer 

behavior. Moreover, the benefits of these new technologies will not be realized until several years of baseline data has been 

collected and used to establish accurate residential profiles that can be relied upon for future forecasting.

Energy Efficiency and Conservation Programs

The recent growth of energy efficiency and conservation programs has had a substantial impact on the rate of load growth. 

Incorporating the impact of these programs into the load forecast requires special attention to consumer behavior, impacts 

of current and future economic conditions, and the overall effectiveness of a given program—all three of which are difficult 

to measure. The growth of energy efficiency programs depends on the behavioral response of participants (or consumers), 

which is impacted by a variety of circumstances, including the program’s structure and the overall economic conditions.

Ultimately, overestimating the impacts of these programs could result in inaccurate load forecasts, potentially impacting 

reliability.

System Behavior Impacts Due to Changing System Resource Mix and Load Compositions

Resource Mix: This includes generation characteristics, frequency response, and inertia requirements. Robust and riskoriented planning and modeling approaches will be needed to address transmission and operating reliability. Incorrect 

assumptions and methods can lead to incorrect decision making for system reinforcement, resources, transmission, flexibility, 

and operational needs.

Load Composition: Continued increases in energy-efficient products (including newer air conditioners, compact fluorescent 

and LED lighting, plasma, LCD and LED televisions, and other electronically coupled loads) are significantly changing the 

characteristics and behavior of system load, particularly during system disturbances. Preliminary studies indicate that such 

changes may exacerbate emerging problems, such as fault-induced delayed voltage recovery (FIDVR). An immediate gap is 

the inability of current load-modeling methods to predict system behavior with the integration of new electronically coupled 

loads. The changing nature of the load requires immediate improvements and additional sophistication in load modeling to 

properly analyze potential system performance issues.

High Levels of Distributed Energy Resources Create New Operational and Planning Challenges

Large amounts of DERs on the system could result in under-voltage or under-frequency tripping due to contingencies that

could potentially impact BPS stability. Because frequency is a wide-area phenomena, resources set to allow minimal tolerance 

for frequency deviations (i.e., current solar PV units connected at the distribution level) can significantly impact BPS reliability, 

particularly when sharing identical trip points.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

31

As an example, Germany has an installed capacity of over 10,000 MW of distributed PV and has recognized the need to 

integrate DERs into their network’s dynamic support; they have proposed the following:

1. Prevent DERs from disconnecting from the system due to faults on the system;

2. Require DERs to support the network voltage during faults by providing reactive power into the system; and

3. Require DERs to consume the same or less reactive power after the fault clearance as prior to the fault.

Distributing generation resources throughout the power system can also have a beneficial effect if the generation has the 

ability to supply reactive power and is coordinated by the System Operator. Without this ability to control reactive power 

output, performance of the transmission and distribution system can be degraded. Given the growing penetration of 

distribution-connected variable generation, there is an increasing need to understand its characteristics and overall 

contribution to ERSs.

Potential Operational Risks Associated with Interaction of Special Protection Systems and Remedial Action Schemes

Special Protection Systems (SPSs) and Remedial Action Schemes (RASs) provide alternatives to the addition of new 

transmission facilities. System Operators need to be aware and informed of SPS and RAS devices in service, as well as the 

corresponding impacts associated with these devices. The lack of modeling requirements and real-time analysis capabilities 

of an SPS/RAS reduces the planners’ and operators’ capability to evaluate the reliability impact of installing these tools on 

the system. These tools also had important implications during the Southwest outage in September 2011.73

Regional/Interconnection-Wide Modeling

Examining interconnection-wide phenomena is necessary for industry to more effectively address frequency response, 

inertial response, small-signal stability, extreme contingency impacts, and geomagnetic disturbances. To support improved 

system performance and planning, validated models should accurately represent actual equipment performance in 

simulations. All devices and equipment attached to the electric grid must be modeled to accurately capture how that 

equipment performs under static and system disturbance conditions. Models provided for equipment must be open-source 

and shareable across the industry to support reliability.

System modeling issues have been identified in several significant system events during the past two decades (the latest 

being the Arizona-Southern California Outages74). Issues cover the full range of systems (i.e., transmission, generation, loads,

and protection) and, more importantly, the interaction between all components. NERC has advanced the development of 

appropriate modeling standards, and the industry as a whole has begun addressing various pieces and parts of the modeling 

issues. 

While the industry has made significant improvements in modeling practices, it continues to address issues and future system 

modeling needs, such as the following:

 Standardized component models (to gain consistency in static and dynamic models used for power system 

studies).

 Consistency in model parameters (to eliminate discrepancies between real-time contingency analysis and planning 

models).

 Benchmarking static and dynamic models (to close the gap between study results with real-world behavior of the 

power system network).

 Modeling a greater array of system components (to ensure greater accuracy in real-time and off-line studies).

Transmission Siting, Permitting, and Other Right-of-Way Issues

According to the 2014LTRA reference case, transmission additions during the 10-year period include 7,400 circuit miles of 

lines currently under construction, 20,622 circuit miles of planned lines, and 7,360 miles of conceptual lines. NERC continues 

 

73 NERC Southwest Blackout Event Reports.

74 Arizona-Southern California Outages.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

32

to monitor the progress of transmission projects across North America, and while transmission planning is dynamic (i.e., a 

planned project can later be deemed unnecessary due to reasons such as a reduction in load growth), resource planners 

should recognize the typical planning periods required to build transmission.

Workforce Transformation

Projected retirements in the electricity industry during the next decade will require a well-trained industry workforce 

(primarily engineers). Workers entering the power industry will be tasked with understanding and implementing a variety of 

new technologies with smarter systems and devices as the BPS continues to rapidly evolve. The electric power industry is 

addressing this issue by creating partnerships between academia and the industry through internship and training programs. 

Aging Infrastructure

Reliable operation of the electric system relies on an interconnected system of generation transmission and local distribution 

elements. The North American BPS was built over the course of a century and therefore, the age of the infrastructure varies

widely. Maintaining the transmission system has many challenges, such as the unavailability of spare parts, the obsolescence 

of older equipment, the potential inability to maintain system reliability due to outage scheduling restrictions, as well as 

reliably integrating new technologies. Investment in new transmission infrastructure in the United States by investor-owned 

utilities has increased substantially over the past 15 years but varies significantly across NERC Regions.

75 The implementation 

of any replacement strategy and in-depth training programs requires additional capital investment, engineering and design 

resources, and construction labor resources, all of which are in relatively short supply. The electricity industry is committed 

to continual upgrade and maintenance of the electricity infrastructure.

 

75 EIA: Today in Energy - Electricity Transmission Investments Vary by Region.
Key Reliability Findings

NERC | 2014 Long-Term Reliability Assessment | November 2014

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Assessment Area Reliability Findings

FRCC

Localized Gas Supply Reduction in Extreme Events

Weather events in the Gulf of Mexico could potentially have an impact on the availability and transportation of natural gas. 

However, dual-fuel capability and on-shore gas resources (with the use of fracking technologies) would mitigate any natural 

gas transportation and supply issues in extreme weather events, such as hurricanes.

MISO

Risks Associated with Potential Generation Retirements and Addition of Natural Gas Resources

Studies have shown that with EPA MATS regulations, MISO could lose 23,000 MW of coal capacity and subsequently increase 

their natural gas generation within MISO’s footprint. MISO has a number of available tools as an ISO/RTO to minimize the 

potential long-term reliability impacts of fuel supply and transportation constraints. If necessary, MISO may need to modify 

their tariff to minimize potential reliability impacts of growing demand and supply/transportation constraints of natural gas.

MRO-Manitoba Hydro

Increase in Variable Resource (Decrease in System Inertia) in Neighboring Systems

Manitoba Hydro is monitoring potential changes to renewable portfolio standards in neighboring areas, especially Minnesota. 

Renewable portfolio standards have the potential to cause a reduction in system inertia, which can impact the operation of 

Manitoba’s HVdc converters or cause other potential reliability concerns, like activation of under-frequency load shedding

relays for single contingencies. Southern Manitoba is quite sensitive to inertia changes due to the relatively large amount of 

HVdc converters connected and sensitive UFLS settings.

MRO-MAPP

High Load Growth Projections

MAPP’s projection of 2.77 percent load growth is partially due to localized growth in northwestern North Dakota and in 

Rochester, Minnesota. The potential for minor instability issues is currently being studied; however, the MAPP Assessment 

Area does not foresee any reliability or resource adequacy issues during the assessment period.

MRO-SaskPower

Impacts of Retirement of Thermal Generation and Addition of Variable Resources

The requirement to reduce emissions for thermal generating facilities will require ongoing resource planning to ensure that 

retrofitting or the addition of new emission control equipment is done in a timely manner. Saskatchewan is working with 

both the provincial and federal governments on emission regulations and equivalency agreements. Saskatchewan will have 

an increase in wind integration in the near-term and long-term planning horizons. The inclusion of more intermittent 

resources may have operational impacts that need to be studied to determine the power system effects to both 

Saskatchewan and neighboring jurisdictions. Depending on the make-up of the future generation resources, intermittent 

resources may need to be curtailed, or other generation sources may be required before coming on-line to allow for the 

sudden changes in output.

NPCC-Maritimes

Increase in Renewable Resources with Retirement of Coal-Fired Generation

Parts of the Maritimes Area are seeking to displace significant amounts of fossil-fueled generation with renewable resources. 

Increasing amounts of renewable resources could affect BPS reliability if variable- or low-mass slow-speed units are added 

without considering (1) the impact of frequency response after system contingencies, or (2) the need for transmission 

enhancements to address and prevent the potential for voltage or overload problems.
Key Reliability Findings

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NPCC-New England

Increase in PV Resources

In New England, there has been significant growth of DERs, especially PV resources that constitute the largest portion 

throughout the area. Therefore, ISO-NE’s analysis of DERs focuses exclusively on the impact of projected PV. To help address 

the interrelated questions of exactly how much additional PV is expected in the ISO’s 10-year planning horizon and what 

impact this future PV could have on the regional power grid, the ISO, in conjunction with stakeholders, endeavored to create 

a forecast of all future PV resources.

NPCC-New York

Environmental Regulations

State and federal regulatory initiatives cumulatively will require considerable investment by the owners of New York’s existing 

thermal power plants, and as much as 33,200 MW in the existing fleet will have some level of exposure to the new regulations.

NPCC-Ontario

Aging Infrastructure

Asset renewal is a systematic approach for the continuous modernization of aging energy infrastructure. Much of the current 

power system infrastructure in generation, transmission, or distribution equipment is aging and needs to be refurbished, 

replaced, or upgraded to comply with new standards and meet demand. A long-term energy plan has been developed to 

coordinate the renewal of infrastructure to manage reliability, environmental, and cost impacts.

NPCC-Québec

Increase in Wind Generation

With the increasing amount of wind on the system, there is a potential for impacts on system management. Main topics 

under study include: (1) wind generation variability on system load and interconnection ramping, (2) frequency and voltage 

regulation, (3) increase of start-ups/shutdowns of hydroelectric units due to load following coupled with wind variability, (4)

efficiency losses in generating units, and (5) reduction of low-load operation flexibility due to low inertia response of wind 

generation coupled with must-run hydroelectric generation.

PJM

Extreme Weather Natural Gas Supply/Transportation

PJM is investigating gas supply and transportation risk by considering the potential correlation with extreme weather (and 

high winter loads) and the potential for the loss of multiple units due to gas transportation disruptions. Gas supply and 

transportation risks are captured in PJM’s resource planning studies to the extent they impact generator forced outage rates. 

All forced outages, whether outside management control or not, are included in the calculations used in planning studies. 

PJM currently assumes all forced outage rates are random across all seasons and independent of each other. 

SERC

RTO Integration Operational Management Challenges 

Within this expanded MISO Balancing Area, market dispatches that result in power transfers between the midwest and south 

portions of the system can result in significant unscheduled power flows through neighboring systems (Tennessee Valley 

Authority (TVA), Associated Electric Cooperative, Inc. (AECI), Louisville Gas & Electric Company and Kentucky Utilities 

Company (LG&E/KU), Power South, Southwest Power Pool, Inc. (SPP), and Southern Company). To date, no long-term joint 

planning studies have been conducted to determine long-term transmission system impacts and any consequent reliability

impacts. MISO and the neighboring systems have initiated discussions surrounding coordinated long-term planning studies.

In addition, SERC regional study groups are assessing and refining SERC modeling and reliability assessments to better reflect 

the expanded MISO BA in regional long-term planning and operational planning assessments.
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SPP

RTO Integration Operational Management Challenges 

SPP, along with other joint parties in the Region and MISO, is currently managing reliability concerns from MISO’s recent 

operational changes under the provisions of the Operations Reliability Coordination Agreement (ORCA). SPP and MISO have 

recently agreed to improvements to the method for accounting for the flow impacts of import and export transactions used 

in the congestion management process. Both parties are continuing to discuss additional improvements to ensure all sources 

of flows are properly accounted for within and between RTOs.

TRE-ERCOT

Weather-Related Resource Adequacy

Multi-year droughts in Texas continue to represent a reliability concern. Much of central Texas and the panhandle are 

currently under “exceptional” or “extreme” drought conditions. If drought conditions extend into 2015, there is the risk of 

multiple resources being taken off-line due to the lack of cooling water, with resource adequacy becoming an issue if 

operational restrictions extend over peak load periods.

WECC

Impacts of Retirement of Thermal Generation and Addition of Variable Resources and Natural Gas Units

In 2013, more than 4,700 MW of thermal generation (2,250 MW of nuclear, 909 MW of coal-fired, and 1,588 MW of gasfired) was retired, and 9,500 MW was added (including 5,200 MW of variable resources such as wind and solar, and 3,162 

MW of gas-fired). WECC is studying the impacts of potential planning and operational reliability impacts associated with the 

retirement of large thermal generating units alongside the impacts from higher levels of variable resources and natural gas 

supply and transportation conditions.
NERC | 2014 Long-Term Reliability Assessment | November 2014

36

FRCC

Assessment Area Overview

The Florida Reliability Coordinating Council’s (FRCC) membership includes 30 Regional Entity Division members and 23 Member Services 

Division members composed of investor-owned utilities (IOUs), cooperative systems, municipal utilities, power marketers, and 

independent power producers. FRCC is divided into 10 Balancing Authorities with 70 registered entities (both members and nonmembers) 

performing the functions identified in the NERC Reliability Functional Model and defined in the NERC Reliability Standards. The Region 

contains a population of over 16 million people and has a geographic coverage of about 50,000 square miles over Florida.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

The Florida Public Service Commission’s 15 percent reserve margin 

criteria for non-IOUs is applied as the Reference Margin Level.

Load Forecast Method

Noncoincident, based on individual LSE forecasts

Peak Season

Summer

Planning Considerations for Wind Resources

No wind capacity; no formalized method

Planning Considerations for Solar Resources

Small amount of solar capacity; no formalized method

Footprint Changes

Region is the Assessment Area footprint; no recent changes

Peak Season Demand, Resources, and Reserve Margins76

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 46,719 47,615 48,501 49,147 49,852 50,554 51,263 52,049 52,981 52,981

Demand Response 3,140 3,173 3,242 3,288 3,373 3,427 3,461 3,491 3,523 3,523

Net Internal Demand 43,579 44,442 45,259 45,859 46,479 47,127 47,802 48,558 49,458 49,458

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 55,520 55,858 56,022 56,081 57,312 57,638 58,783 60,214 61,370 60,794

Prospective 57,311 57,827 58,036 58,110 59,874 60,202 61,806 63,237 64,393 63,988

Adjusted-Potential 57,311 57,827 58,036 58,110 59,874 60,202 61,806 63,237 64,393 63,988

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 27.40% 25.69% 23.78% 22.29% 23.31% 22.30% 22.97% 24.00% 24.09% 22.92%

Prospective 31.51% 30.12% 28.23% 26.71% 28.82% 27.74% 29.30% 30.23% 30.20% 29.38%

Adjusted-Potential 31.51% 30.12% 28.23% 26.71% 28.82% 27.74% 29.30% 30.23% 30.20% 29.38%

Reference Margin Level 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 5,404 4,750 3,974 3,343 3,861 3,442 3,811 4,372 4,493 3,917 

Prospective 7,195 6,718 5,988 5,372 6,423 6,006 6,833 7,395 7,516 7,111 

Adjusted-Potential 7,195 6,718 5,988 5,372 6,423 6,006 6,833 7,395 7,516 7,111 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

 

76 The FRCC plans through 2023.

10%

15%

20%

25%

30%

35%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-2

-1

0

1

2

3

4

5

6

7

8

9

10

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Petroleum Natural Gas Nuclear Renewables
FRCC

NERC | 2014 Long-Term Reliability Assessment | November 2014

37

Demand, Resources, and Planning Reserve Margins

Based on the expected load and generation capacity, all three the Anticipated, Prospective, or Adjusted-Potential Reserve

Margins are above 22 percent for the FRCC Assessment Area for all seasons during the assessment period. Compared to the 

2013LTRA, FRCC projects a small decrease in the 2015 summer net peak demand; it then returns to historical weathernormalized demand growth levels similar to last year’s projections for the same time period. The winter net peak demands 

are projected to be approximately 3.9 percent lower compared to the 2013 projections for the same time period. This is 

attributed to revisions to the winter peak projections that remove the overestimation of the impact of past cold weather.

Demand Response (DR) from interruptible and load management programs within FRCC is treated as a load modifier and is 

projected to be relatively constant at approximately 6.6 percent of the summer and winter total peak demands for all years 

of the planning horizon. In 2014, Florida is setting DSM goals for the years 2015–2024 in the Demand-Side Management goals 

docket with the Florida Public Service Commission, which is held every five years. New DSM goals for both DR and energy 

efficiency will be set in this docket; a decision is expected in the fourth quarter of 2014. A key reason for the proposed 

reduction is a significant decrease in the cost-effectiveness of DSM. Since the DSM goals were set in 2009, fuel price forecasts

have dropped by approximately 50 percent, and projected environmental compliance costs, particularly for CO2 emissions,

have dropped. These changes result in a significant lowering of the projected DSM benefits from kWh reductions. These 

factors result in both fewer DSM options being cost-effective, and a lowering of incentive payments to DSM participants for 

other DSM options for them to remain cost-effective, which reduces the number of DSM participating customers. In addition, 

the projected impact of federal and state energy efficiency codes and standards has deferred a number of utility DSM 

programs that would have addressed the electrical equipment affected by these codes and standards, effectively reducing 

market potential for utility DSM programs. However, the projected impact of these codes and standards is accounted for in 

the utilities’ load forecasts, thus reducing projected resource needs in an identical way as would occur if these impacts were 

delivered by utility DSM programs.

FRCC projects 12,613 MW (summer) and 13,608 MW (winter) of additional generation to come on-line during the assessment 

period. The proposed generation additions are studied by the Interconnecting Transmission Owner, as well as by the FRCC 

Transmission Working Group (TWG) through the FRCC’s Transmission Service and Generator Interconnection Service Request 

Regional Deliverability Evaluation Process. FRCC projects 3,391 MW (summer) and 3,619 MW (winter) generation to be 

retired through the assessment period. FRCC is not anticipating any reliability impacts resulting from these unit retirements. 

The unit retirements are being studied as part of the FRCC Long-Range Study process performed annually by the TWG and 

the Resource Working Group (RWG) to mitigate potential reliability impacts to the grid and the FRCC reserve margin criteria.

Entities within FRCC have generation under Firm contract available to be imported into the Assessment Area from SERC. In 

addition, approximately 840 MW of FRCC member-owned generation is dynamically dispatched out of the SERC Assessment 

Area. These purchases have Firm transmission service to ensure deliverability into the FRCC Assessment Area.

In 2013, FRCC conducted a study identifying the impacts of the retirement of two coal-generating units (915 MW) starting 

April 2015 as an option to comply with MATS. These two units, combined with the recent retirement of an 825 MW unit at 

the same site, result in a total generation reduction of 1,740 MW from this site. The Assessment Area study determined that 

the proposed retirements of the two coal plants would have an impact on the BES transmission system; however, the plants 

have received an extension of the retirement date. The extension provides sufficient time to modify the plants, then construct 

transmission projects and the replacement of natural-gas-fired units to maintain the reliability of the BES within FRCC.

The FRCC Fuel Reliability Working Group (FRWG) has recently completed a natural gas pipeline study evaluating the loss of 

key compressor stations in the Assessment Area and the gas supply impacts resulting from an offshore hurricane. The results 

of these studies indicated that the FRCC Assessment Area would not have a large-scale impact from extreme events. Some 

localized gas reduction could occur; however, dual-fuel capability could be utilized if additional generation is required. 

Because of the expanded use of fracking technology, more gas is coming from on-shore sources rather than offshore sources, 

further reducing potential impacts from hurricanes in the Gulf of Mexico.
NERC | 2014 Long-Term Reliability Assessment | November 2014

38

MISO

Assessment Area Overview

The Midcontinent Independent System Operator, Inc. (MISO) is a not-for-profit, member-based organization administering wholesale 

electricity markets that provide customers with valued service, reliable, cost-effective systems and operations, dependable and transparent 

prices, open access to markets, and planning for long-term efficiency. MISO manages energy, reliability, and operating reserves markets 

that consist of 36 local Balancing Authorities and 394 market participants, serving approximately 42 million customers. The MAPP portion 

of the MISO Reliability Coordination Area is reported separately in the MRO-MAPP section of this report. Although parts of the MISO fall in 

three NERC Regions, MRO is responsible for coordinating data and information submitted for NERC’s reliability assessments.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

For planning year 2014–2015, MISO’s System-Installed Generation 

Planning Reserve Margin requirement (PRMR) is 14.8 percent, 

which is applied as the Reference Margin Level for all 10 years.

Load Forecast Method

Coincident

Peak Season

Summer

Planning Considerations for Wind Resources

Effective Load-Carrying Capability (ELCC); varies by wind node

Planning Considerations for Solar Resources

No utility-scale solar resources in MISO

Footprint Changes

December 2013: Integration of the MISO South resulted in an 

expanded footprint.

77

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 128,571 130,101 131,242 132,376 133,470 134,509 135,526 136,460 137,377 138,433

Demand Response 4,743 4,755 4,766 4,779 4,791 4,803 4,815 4,827 4,839 4,851

Net Internal Demand 123,828 125,345 126,475 127,598 128,679 129,707 130,711 131,633 132,538 133,582

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 144,893 141,510 143,669 143,225 142,852 142,889 141,221 140,921 139,821 139,521

Prospective 150,055 147,380 149,538 150,694 151,121 153,246 153,178 153,178 153,178 153,178

Adjusted-Potential 150,258 147,754 150,075 151,374 151,917 154,134 154,086 154,181 154,317 154,317

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 17.01% 12.90% 13.59% 12.25% 11.01% 10.16% 8.04% 7.06% 5.50% 4.45%

Prospective 21.18% 17.58% 18.23% 18.10% 17.44% 18.15% 17.19% 16.37% 15.57% 14.67%

Adjusted-Potential 21.34% 17.88% 18.66% 18.63% 18.06% 18.83% 17.88% 17.13% 16.43% 15.52%

Reference Margin Level 14.80% 14.80% 14.80% 14.80% 14.80% 14.80% 14.80% 14.80% 14.80% 14.80%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 2,739 (2,387) (1,525) (3,258) (4,871) (6,014) (8,835) (10,193) (12,332) (13,831)

Prospective 7,901 3,484 4,344 4,211 3,398 4,343 3,122 2,064 1,025 (174)

Adjusted-Potential 8,104 3,857 4,882 4,892 4,193 5,231 4,030 3,066 2,164 965 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

 

77 Includes Entergy Arkansas, Inc., Entergy Texas, Inc., Entergy Mississippi, Inc., Entergy Louisiana, LLC, Entergy Gulf States Louisiana, L.L.C., Entergy New 

Orleans, Inc., Cleco Power LLC, Lafayette Utilities System, Louisiana Energy & Power Authority, South Mississippi Electric Power Authority, and Louisiana 

Generating, LLC.

0%

3%

6%

9%

12%

15%

18%

21%

24%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-6

-5

-4

-3

-2

-1

0

1

2

3

4

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Petroleum Natural Gas

Renewables Pumped Storage Hydro
MISO

NERC | 2014 Long-Term Reliability Assessment | November 2014

39

Demand, Resources, and Planning Reserve Margins

For planning year 2014–2015, MISO’s System-Installed Generation Planning Reserve Margin requirement (PRMR) on a MISO 

coincident load basis is 14.8 percent, 0.6 percentage points higher than the 2013–2014 requirement. However, the PRMR for 

zone 8 (primarily covering the state of Arkansas) was set by the Local Clearing Requirement for zone 8, because the local 1-

day-in-10 reliability criteria was higher than the system requirement. This resulted in a higher PRMR for zone 8. The major 

drivers of the change include: the MISO South integration, the adjustment to the amount of external support that can be 

used in time of need, and the ongoing improvement of MISO’s load forecast uncertainty values. MISO performs out-year LOLE

studies but only has a PRMR for the current planning year. For this assessment, the current planning year PRMR of 14.8 

percent is used for the entire 10-year period.

MISO projects that the Anticipated Reserve Margin will drop below the 14.8 requirement in 2016 and stay below the 

Reference Margin Level for the remainder of the assessment period. The 14.8 requirement is determined by the 1-day-in-10-

year LOLE criteria. Dropping below the Reference Margin Level (planning reserve margin requirement) means that the MISO 

system will have an increased chance of an LOLE; in 2016, MISO projects it will operate at the reliability level of approximately 

2-days-in-10-year LOLE. As MISO starts to operate at or near the Reference Margin Level, there is a higher likelihood that 

System Operators will call Emergency Operating Procedures more frequently to access Emergency-Only resources, loadmodifying resources, and BTMG. The contributing factors driving the projected deficit include:

 Increased retirements and suspensions (temporary mothballing) due to Environmental Protection Agency (EPA)

regulations and market forces and low natural gas prices

 Exclusion of low-certainty resources that were identified in the Resource Adequacy survey

 Exclusion of surplus of capacity in MISO South above the 1,000 MW transfer from the Planning Reserve Margin 

requirement (PRMR)

78

 Increased exports to PJM and the removal of non-Firm imports79

 Inadequate Tier 1 capacity additions 80

MISO recently completed a Resource Adequacy survey in 2014 with assistance from load-serving entities (LSEs) and the 

Organization of MISO States (OMS). This survey provided additional visibility on the resource adequacy outlook to help 

address falling below the Reference Margin Level.

81 The survey also identified resources that had a low certainty of being 

available for each planning year. This assessment excludes these low-certainty resources from the Anticipated Resources and 

corresponding Reserve Margin.82

As a result of the risk associated with falling below the Reference Margin Level, MISO is conducting a study of the unused 

capacity that does not currently qualify as planning resources in MISO’s planning resource auction.83 The unused capacity 

comes from two places: (1) generators with generator-verification-tested capacity that is higher than the Total 

Interconnection Service; and (2) energy-only portions of generators. With the completion of this study, projects will be 

identified that would allow those resources to qualify as a planning resource, eligible for participation in the planning resource 

auction.

 

78 For this assessment, 1,000 MW of capacity is transferred from the MISO South to the MISO North/Central Region pending the outcome of regulatory 

issues currently under FERC review.

79 Capacity sales (imports and exports) in MISO depend on decisions of the respective resource owners, assuming that the tariff requirements are met 

(including planning of necessary transmission of both the buying and selling areas). Regarding the removal of non-Firm imports, the MISO market 

monitor double-counted non-Firm imports in the 2013LTRA reference case. These imports are accounted for in the Reference Margin Level (PRMR).

80 In the MISO footprint, 91 percent of the load is served by utilities with an obligation to serve customers reliably and at a reasonable cost. Resource 

planning and investment in resources are part of state and locally jurisdictional integrated resource plans that only become certain upon the receipt of a 

Certificate of Public Convenience and Necessity (CPCN).

81 Synonymous with the MISO term, “Planning Reserve Margin Requirement.”

82 Low-certainty resources identified in the survey are included in the Prospective Resources and corresponding reserve margin.

83 MISO Resource Adequacy.
MISO

NERC | 2014 Long-Term Reliability Assessment | November 2014

40

The Prospective and Adjusted-Potential Reserve Margins remain above the 14.8 percent Reference Margin Level for the entire 

assessment period. Prospective Resources include low-certainty resources identified in the resource adequacy survey, 

Existing-Other capacity, and 50 percent of all Tier 2 capacity additions,84 while the Adjusted-Potential resources includes 10 

percent of additional Tier 3 capacity additions.85 Although the Anticipated Reserve Margin is projected to fall below the 

Reference Margin Level in 2016, MISO fully expects that the Reference Margin Level shortfall will change significantly once 

LSEs and state commissions within the footprint solidify future capacity plans, as reflected in the Prospective and AdjustedPotential Margins.

MISO forecasts the coincident Total Internal Demand to peak at 128,571 MW during the 2015 summer season. The major 

driver for the increased demand, compared to the 2013LTRA reference case, is the integration of the MISO South entities. 

MISO projects the summer coincident peak demand to grow at an average annual rate of 0.85 percent.

MISO projects between 4,743 MW and 4,851 MW of DR86 to be available during the 10-year outlook. Additionally, 4,300 MW 

of BTMG is assumed to be available throughout the assessment period, included as Existing-Certain capacity. No growth in

BTMG is projected at this time.

Firm imports into the MISO footprint amount to 3,157 MW. These imports are unable to be recalled by the source 

Transmission Service Provider (TSP) and were designated to serve load within MISO through the Module E process for summer 

2014. The 3,157 MW of imports apply for the entire assessment period. MISO also assumes 2,044 MW of Firm exports to the 

PJM footprint for 2015, based on the cleared results of the PJM Base Residual Auction. Exports are projected to increase to 

4,135 MW in 2016 and remain at that level for the remainder of the assessment period.

For this assessment, transfers between MISO South and MISO North/Central are limited to 1,000 MW, pending the resolution 

of the ongoing dispute regarding the MISO-SPP Joint Operating Agreement, which is currently under review at FERC. Any 

surplus capacity in MISO South beyond the 1,000 MW transfer and the MISO South PRMR is treated as Transmission-Limited 

Resources (TLR) for the purpose of this assessment. The amount of TLRs declines each year until reaching zero in the summer 

of 2021 due to a combination of load growth in MISO South, increasing capacity exports, and minimal capacity retirements.

Transmission Outlook and System Enhancements

The MISO Transmission Expansion Plan proposes transmission projects to maintain a reliable electric grid and deliver the 

lowest-cost energy to customers in the footprint. As part of the 2013 MISO Transmission Expansion Plan,

87 MISO staff 

recommends $1.48 billion of new transmission expansion expenses through 2023, as described in Appendix A, to the MISO 

Board of Directors for review, approval, and subsequent construction. The table below shows notable transmission projects 

approved as part of the 2013 MISO Transmission Expansion Plan:

 Petersburg – Francis Creek – Hanna Line 345 kV Line Rating Increase (Indianapolis Power and Light): May 2014

 Overton Transformer Replacement (Ameren Missouri): June 2014

 Straits Power Flow Control (American Transmission Company): July 2014

 Lafayette 230kV Substation Bus Modernization – Phase 1 (Duke Indiana): December 2014

 Stone Lake – Edgewater 161 kV (Xcel Energy): December 2014

 Pottawattamie County Substation and Po. County – Sub 701 161kV (MidAmerican Energy): December 2014

 Monroe County – Council Creek 161 kV (American Transmission Company): March 2015

 Lenawee 345/138 kV station (Michigan Electric Transmission Company): April 2015

 Turkey Hill – Cahokia and Cahokia Substation Upgrade (Ameren Illinois): June 2015

 Kokomo Highland Park to Tipton West 230 kV Line Rebuild (Duke Indiana): June 2015

 

84 Resources currently under study in the MISO interconnection queue awaiting signed Interconnection Agreements.

85 Resources that were identified in the Resource Adequacy survey but are not currently in the MISO interconnection queue.

86 MISO’s Demand Response Programs consist of Direct Control Load Management (DCLM) and Interruptible Load (IL).

87 The MISO Transmission Expansion Plan for 2013.
MISO

NERC | 2014 Long-Term Reliability Assessment | November 2014

41

 Bland 345/138 kV Substation (Ameren Missouri): December 2015

 Battle Creek – Island Road 138 kV Rebuild (Michigan Electric Transmission Company): December, 2015

 Five Points 230kV Substation Upgrade – Phase I (Duke Indiana): December 2015

 Marshall – Blackstone 138 kV Rebuild (Michigan Electric Transmission Company): December 2015

 Toll Road (ITC Transmission): December 2015

 Lafayette 230kV Substation Bus Modernization – Phase 2 (Duke Indiana): December 2016

 North Appleton – Morgan 345+138 kV, Holmes – 18th Road 138 kV (American Transmission Company): December 

2016

Long-Term Reliability Issues

There continues to be significant risk associated with potential retirements during the assessment period. Previous studies 

have shown that considering all EPA regulations, MISO would potentially retire 23 GW of coal-fired capacity. Without final 

regulations, excluding MATS, final retirement decisions continue to be far below the 23 GW of potential retirements.

The early-2014 polar vortex brought extreme weather conditions to the MISO Region that introduced significant challenges 

to the reliable operation of the power grid. The effects were far reaching, spanning from the Canadian province of Manitoba 

to the Gulf Coast. MISO will perform a comprehensive review of this event and identify any lessons learned. Initial findings 

include the realized benefits of improved coordination with the gas pipeline operators, as well as the risk mitigation efforts 

achieved by proactive staff planning. The substantial variation in DSM availability between seasons was also noted, which 

MISO will study further with continued efforts targeted at improving the visibility and management of these resources. 

To maximize preparedness for repeated extreme weather events, MISO will continue efforts to improve coordination 

between the electric and gas industries through the Electric-Natural Gas Coordination Task Force (ENGCTF).

88 Ongoing efforts

include the continuation of field trials with the pipelines to identify improvement opportunities and establish best practices.

MISO has a number of available tools as an ISO/RTO to minimize the potential long-term reliability impacts of fuel supply

and/or transportation constraints. Tools include modifying the MISO tariff. The extent that MISO will need to use these tools, 

(i.e., will need to modify market, planning, and operational constructs) is an ongoing conversation with our stakeholders. To 

address this question in the context of growing demand for natural gas, MISO’s ENGCTF focused on the following objectives: 

(1) educate and build a common knowledge base between the gas and electric industries; (2) identify gas-electric coordination 

challenges and issues; (3) educate MISO entities on this issue; (4) develop potential solutions to these issues; and (5) 

thoroughly evaluate how all stakeholder groups could be impacted by these solutions. Before implementing any initiatives, 

MISO considers potential costs and benefits, as well as the reliable and efficient operation of the transmission system.

Specific initiatives from the ENGCTF include: (1) enhancing system awareness through control room improvements, such as 

the introduction of an overlay display for natural gas and transmission, an online platform for notices from all pipelines in the 

MISO footprint, and a database linking generators to their fuel sources; (2) improving cross-industry communicationsthrough 

MISO’s six-month Coordination Field Trial with two major interstate pipeline companies, which has been extended through 

2014; (3) scheduling monthly and as-needed conference calls between MISO Operation and Planning staff and natural gas 

pipeline operations staff; and (4) examining system impacts of interdependency.

89

 

88 MISO Electric and Natural Gas Coordination Task Force. 

89 For example, the 2014 Issue Summary Papers on the impacts of the polar vortex and the potential for competition between NG storage injection and 

power burn demand.
NERC | 2014 Long-Term Reliability Assessment | November 2014

42

MRO-Manitoba Hydro

Assessment Area Overview

Manitoba Hydro is a Provincial Crown Corporation that provides electricity to 548,000 customers throughout Manitoba and natural gas 

service to 270,000 customers in various communities throughout southern Manitoba. The Province of Manitoba is 250,946 square miles. 

Manitoba Hydro is winter peaking. No change in the footprint area is expected during the assessment period. Manitoba Hydro is its own 

Planning Coordinator and Balancing Authority and is a coordinating member of the Midcontinent Independent System Operator (MISO). 

MISO is the Reliability Coordinator for Manitoba Hydro.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

The capacity criterion, as determined by Manitoba Hydro, requires 

a minimum 12 percent Planning Reserve Margin, applied as the 

Reference Margin Level in this assessment.

Load Forecast Method

Coincident

Peak Season

Winter

Planning Considerations for Wind Resources

Effective Load-Carrying Capability (ELCC) of 14.1 percent for the 

summer; wind is derated entirely for the winter season.

Planning Considerations for Solar Resources

No utility-scale solar resources

Footprint Changes

N/A

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 4,652 4,713 4,663 4,705 4,761 4,854 4,931 4,997 5,066 5,136

Demand Response 243 244 244 244 244 244 244 244 244 244

Net Internal Demand 4,409 4,469 4,419 4,461 4,517 4,610 4,687 4,753 4,822 4,892

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 5,637 5,521 5,521 5,671 5,847 6,257 6,365 6,365 6,365 6,365

Prospective 5,901 5,785 5,785 5,935 6,111 6,271 6,154 6,179 6,179 6,179

Adjusted-Potential 5,901 5,785 5,785 5,935 6,111 6,271 6,154 6,179 6,179 6,179

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 27.85% 23.54% 24.93% 27.14% 29.44% 35.71% 35.78% 33.91% 32.00% 30.11%

Prospective 33.83% 29.44% 30.90% 33.05% 35.28% 36.01% 31.28% 29.99% 28.13% 26.30%

Adjusted-Potential 33.83% 29.44% 30.90% 33.05% 35.28% 36.01% 31.28% 29.99% 28.13% 26.30%

Reference Margin Level 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 699 516 572 675 788 1,093 1,115 1,041 964 886 

Prospective 963 780 835 939 1,051 1,107 904 855 778 700 

Adjusted-Potential 963 780 835 939 1,051 1,107 904 855 778 700 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

9%

12%

15%

18%

21%

24%

27%

30%

33%

36%

39%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Hydro
MRO-Manitoba Hydro

NERC | 2014 Long-Term Reliability Assessment | November 2014

43

Demand, Resources, and Reserve Margins

As a predominately hydro assessment area, Manitoba Hydro has both an energy criterion and a capacity criterion. Manitoba 

Hydro is projecting Anticipated, Prospective, and Adjusted-Potential Reserve Margins to remain above the Reference Margin 

Level for the entire period of the assessment.

At this time, Manitoba Hydro’s long-term resource plans do not include operation of the sole coal generating unit in the 

Manitoba Hydro system (Unit 5, approximately 95 MW and located in Brandon, Manitoba) beyond 2019. Manitoba Hydro 

plans to mothball the unit in 2020 unless directed by the Province of Manitoba to retire the unit at that time. As new 

generating resources are expected to be in service in the 2019 time frame, discontinued operation of Brandon Unit 5 is not 

expected to have a reliability impact.

Manitoba Hydro also anticipates that the first units (270 MW) of the total 630 MW of net capacity addition from the Keeyask 

Hydroelectric Generating Station will begin coming into service in late 2019. This projected in-service date is several years 

ahead of projected needs within Manitoba and allows for flexibility, should there be regulatory or construction delays in the 

project.

Manitoba Hydro has recently updated its energy efficiency and conservation plan. The 2014 Power Smart Plan includes higher 

forecast energy and demand savings as compared with the 2013 Power Smart Plan. These 15-year savings from the 2014 

Power Smart Plan are approximately 2.3 times higher for demand savings and 2.6 times higher for energy savings. The 

increased savings are the result of enhancements to existing programs and the addition of new programs based on 

opportunities identified in the market. Energy efficiency and conservation from the 2013 Power Smart Plan is used in this 

assessment, which is consistent with the values included in the current long-term resource plans. 

All of Manitoba Hydro’s dependable exports and imports are backed by contracts. Manitoba Hydro has up to 825 MW of Firm 

or Expected on-peak transfers (capacity exports) during the winter, up to 550 MW of Firm or Expected on-peak transfers 

(capacity imports) during the winter, and up to 1,425 MW of Firm or Expected on-peak exports in the summer, and associated 

Firm transmission reservations over the 2015–2024 assessment period. Manitoba Hydro does not have any capacity imports 

during the summer. These contractual agreements have Firm transmission reservations with staggered terms associated with 

them. Manitoba Hydro does not have any capacity transactions beyond the contract terms. Some Expected Transfers (Exports 

are contingent upon additional resources being built within the assessment time frame.

Long-Term Reliability Issues

Severe weather events can include tornados and ice storms, for example. These events can occur at any time, but the 

consequence is most severe at or near the system peak load in winter. Loss of a major station or corridor can impact delivery

of generation from hydro generation located in the northern portion of the area, which will impact resource adequacy. 

Manitoba Hydro is planning on adding a major new 500 kV HVdc transmission line and new Riel switching station in order to 

mitigate the loss of the Dorsey converter station and the loss of the Bipole I/II transmission corridor. These facilities are 

planned to be in service by 2017 and are included in the reference case. Transmission siting and permitting issues have the 

potential to delay the in-service date, which will increase Manitoba Hydro’s exposure to the loss of load risk.

Manitoba Hydro is not anticipating any reliability impacts from increased variable resources in Manitoba. However, Manitoba 

is monitoring potential changes to renewable portfolio standards in neighboring areas, especially Minnesota. Renewable 

portfolio standards, resulting in additional VERs, have the potential to cause a reduction in system inertia, which can impact 

the operation of Manitoba’s HVdc converters or cause other potential reliability concerns, including activation of underfrequency load shed relays for single contingencies. Southern Manitoba is quite sensitive to inertia changes due to the 

relatively large amount of HVdc converters connected and sensitive UFLS settings. Manitoba does not have a legislated, 

renewable mandate such as an RPS, and no legislation is currently anticipated. The resource mix in Manitoba is already over 

95 percent renewable under typical inflow conditions.
MRO-Manitoba Hydro

NERC | 2014 Long-Term Reliability Assessment | November 2014

44

Manitoba Hydro is not planning to increase or decrease Demand Response programs and does not foresee any reliability 

impacts associated with the Demand Response loads. There are not significant levels of distributed and BTMG in Manitoba,

and this is not expected to change over the next 10 years. Therefore, no reliability impacts are expected from distributed and 

BTMG.

Manitoba Hydro’s system is predominately hydro, and the operating flexibility of the hydro resource is adequate to meet 

operating requirements during the shoulder (off-peak) periods.

The only remaining coal unit, Brandon Unit 5 (95 MW), is impacted by the Manitoba Climate Change and Emissions Reduction 

Act and the Canadian Federal Coal-Fired Electricity Regulations. This unit is regulated such that it can only be operated to 

provide for emergency operations. At this time, no pending regulations are expected to impact existing gas and hydro 

generation in Manitoba.

The Manitoba Hydro system is predominately hydro and is designed and operated to serve all Firm load requirements under 

the worst inflow conditions on record coincident with high winter load conditions. Manitoba Hydro also accounts for the 

possibility of a drought in its operations planning processes. The largest gas generators in Manitoba, the Brandon Unit 6 and 

7 combustion turbines (119 MW and 118 MW, respectively), are dual fueled natural gas fired with diesel backup.

The adequacy of natural gas pipeline capacity and natural gas generator performance in the Midwest during extreme events, 

and the resulting impact on Manitoba, is being monitored. At this time, no short- or long-term impacts on resource adequacy 

in Manitoba are anticipated.
NPCC-Québec

NERC | 2014 Long-Term Reliability Assessment | November 2014

45

MRO-MAPP

Assessment Area Overview

The Mid-Continent Area Power Pool (MAPP) is an association of electric utilities and other electric industry participants operating in all or 

parts of Iowa, Minnesota, Montana, North Dakota, and South Dakota. Currently, the MAPP Planning Coordinator includes entities in two 

BAs and 13 LSEs. The MAPP covers an area of approximately 200,000 square miles and serves a population of about 3.5 million. MAPP 

typically experiences its annual peak demand in summer, but recently started projecting peak internal demand during the winter seasons.

For this long-term outlook, MAPP is considered a summer-peaking area. However, depending on the load forecasts, MAPP may shift to a 

winter-peaking area in future long-term assessments. There have not been any changes to the MAPP Assessment Area footprint in the last 

two years, and no changes are expected in the future.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

MAPP members use a range of reserve margin targets depending 

on each individual member’s system. However, MAPP provides a 

15 percent Reference Margin Level.

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Summer; however, recent projections indicate higher Total 

Internal Demand during the winter seasons.

Planning Considerations for Wind Resources

Historical data

Planning Considerations for Solar Resources

No utility-scale solar resources

Footprint Changes

The Minnesota Municipal Utilities Association (MMUA) and Ames 

Municipal Utilities (AMES) are now reported in the MISO footprint.

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 5,028 5,374 5,500 5,690 5,810 5,927 6,038 6,145 6,257 6,427

Demand Response 96 98 94 96 98 100 102 104 106 108

Net Internal Demand 4,932 5,276 5,406 5,594 5,712 5,827 5,936 6,041 6,150 6,319

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 6,379 6,505 6,598 6,607 6,599 6,612 6,599 6,621 6,628 6,661

Prospective 6,379 6,535 6,628 6,642 6,599 6,612 6,599 6,621 6,628 6,661

Adjusted-Potential 6,379 6,535 6,628 6,642 6,599 6,612 6,599 6,621 6,628 6,661

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 29.35% 23.30% 22.05% 18.11% 15.52% 13.48% 11.17% 9.60% 7.76% 5.41%

Prospective 29.35% 23.86% 22.61% 18.74% 15.52% 13.48% 11.17% 9.60% 7.76% 5.41%

Adjusted-Potential 29.35% 23.86% 22.61% 18.74% 15.52% 13.48% 11.17% 9.60% 7.76% 5.41%

Reference Margin Level 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 708 438 381 174 30 (89) (227) (326) (445) (606)

Prospective 708 468 411 209 30 (89) (227) (326) (445) (606)

Adjusted-Potential 708 468 411 209 30 (89) (227) (326) (445) (606)

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

0%

3%

6%

9%

12%

15%

18%

21%

24%

27%

30%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-0.2

-0.1

0.0

0.1

0.2

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Natural Gas Renewables
MRO-MAPP

NERC | 2014 Long-Term Reliability Assessment | November 2014

46

Demand, Resources, and Reserve Margins

The Anticipated, Prospective, and Adjusted-Potential Reserve Margins for MAPP are below the Reference Margin Level of 15 

percent beginning in 2020 and remain below it through 2024. MAPP has traditionally always met its target reserve margin 

through the mid-term planning horizon, and beyond that time frame, Firm contracts or capacity additions may be currently 

unknown. The long-term resource adequacy outlook for MAPP will be updated with load projections and the execution of 

long-term contracts, and new capacity additions are planned.

High forecast load growth in Rochester and Minnesota, as well as the ongoing growth of oil and gas development in the 

Bakken Formation in western North Dakota and eastern Montana, has contributed to a Total Internal Demand annual growth 

rate of nearly 3 percent. With Minnesota Municipal Utilities Association (MMUA) and Ames Municipal Utilities (AMES) now 

submitting data through MISO, MAPP demand growth is expected to be lower in the near term, compared to what was 

forecast in the 2013LTRA.

Since the 2013LTRA, the Rochester Public Utilities’ (RPU) Silver Lake Plant (85.2 MW) was decommissioned, while 226 MW of 

capacity was added, of which 146 MW were wind resources. MAPP is projecting 349 MW of imports and 1,289 MW of exports, 

retaining the status of a net exporting Assessment Area with a net export of 940 MW. For these transfers, Firm contracts exist 

for both the capacity and the transmission service. MAPP forecasts meet the various reserve margin targets without needing 

to include energy-only, uncertain, or transmission-limited resources.

Transmission Outlook and System Enhancements

Several transmission projects are projected to be completed during the assessment period, all of which are intended to 

increase the reliability of the MAPP transmission system. RPU is a joint owner of the Hampton – North Rochester – LaCrosse 

portion of the CAPX2020 project; this portion is expected to be in service by 2016. Although it has experienced some delays, 

Minnkota Power Cooperative’s Center – Grand Forks line was scheduled to be completed by July 2014, which will improve 

reliability with additional wind resources coming online.

Long-Term Reliability Issues

The integration of variable resources presents new challenges in the Assessment Area, changing the nature of how the BPS 

is operated. There is expected high load growth in the northwestern North Dakota area and greater load growth projected in

Rochester, Minnesota. There is some minor instability that is currently being studied, and the MAPP assessment area does 

not foresee any reliability or capacity issues becoming problematic during the long-term assessment period.
NERC | 2014 Long-Term Reliability Assessment | November 2014

47

MRO-SaskPower

Assessment Area Overview

Saskatchewan is a province of Canada and comprises a geographic area of 651,900 square kilometers with approximately 1.1 million people. 

Peak demand is experienced in the winter. The Saskatchewan Power Corporation (SaskPower) is the Planning Coordinator and Reliability 

Coordinator for the province of Saskatchewan and is the principal supplier of electricity in the province. SaskPower is a Provincial Crown 

Corporation and under provincial legislation is responsible for the reliability oversight of the Saskatchewan bulk electric system and its 

interconnections.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

Saskatchewan uses an Expected Unserved Energy (EUE) analysis to 

project its Planning Reserve Margins and as the criterion for adding 

new generation resources. This 11 percent margin is applied as the 

Reference Margin Level for this assessment.

Load Forecast Method

Coincident, 50/50 forecast

Peak Season

Winter

Planning Considerations for Wind Resources

10 percent of nameplate (summer); 20 percent of nameplate 

(winter)

Planning Considerations for Solar Resources

No utility-scale solar resources

Footprint Changes

N/A

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 3,557 3,647 3,722 3,846 3,957 3,984 4,029 4,077 4,116 4,141

Demand Response 86 86 86 86 86 86 86 86 86 86

Net Internal Demand 3,471 3,561 3,636 3,760 3,871 3,898 3,943 3,991 4,030 4,055

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 4,309 4,383 4,387 4,437 4,737 4,659 4,540 4,779 4,829 4,829

Prospective 4,309 4,383 4,387 4,437 4,737 4,659 4,540 4,779 4,829 4,829

Adjusted-Potential 4,309 4,383 4,387 4,437 4,737 4,659 4,540 4,779 4,829 4,829

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 24.15% 23.08% 20.65% 18.00% 22.36% 19.52% 15.14% 19.74% 19.82% 19.08%

Prospective 24.15% 23.08% 20.65% 18.00% 22.36% 19.52% 15.14% 19.74% 19.82% 19.08%

Adjusted-Potential 24.15% 23.08% 20.65% 18.00% 22.36% 19.52% 15.14% 19.74% 19.82% 19.08%

Reference Margin Level 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 457 430 351 263 440 332 163 349 355 328 

Prospective 457 430 351 263 440 332 163 349 355 328 

Adjusted-Potential 457 430 351 263 440 332 163 349 355 328 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

8%

10%

12%

14%

16%

18%

20%

22%

24%

26%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Natural Gas Renewables Hydro
MRO-SaskPower

NERC | 2014 Long-Term Reliability Assessment | November 2014

48

Demand, Resources, and Reserve Margins

Saskatchewan plans to meet projected load with Anticipated Resources throughout the assessment period. Based on the 

deterministic calculation made within this assessment, Saskatchewan’s Anticipated Reserve Margin ranges between 13 and 

24 percent, remaining above the Reference Margin Level of 11 percent throughout the assessment period.

Saskatchewan does not anticipate any challenges that would lead to significant detractions of its Planning Reserve Margin 

projections. Greenhouse gas regulations are expected to become an issue as specific federal and provincial regulations are 

introduced and clarified. The consequence of such regulations is expected to have a low impact on reliability, because it is 

expected that sufficient lead time will be given to allow for appropriate mitigation.

The forecast growth rate for Total Internal Demand is 1.7 percent during the winter seasons of the assessment period. Since 

last year’s assessment, the forecast growth in internal demand has decreased slightly, primarily due to reduced economic 

growth forecast.

An upswing in the economy could lead to an increase in electricity usage and cause a spike to the overall demand. 

Saskatchewan has plans in place to meet resource reliability requirements, should a sudden economic change cause a need 

for new capacity. Load growth in Saskatchewan is primarily due to economic growth in the industrial sector and in general is 

spread throughout the province.

It is expected that 170 MW of DSM will be available during the first year of the assessment and 253 MW of DSM will be 

available during year 10 of the assessment period. Projected annual growth in energy efficiency and conservation declines 

throughout the assessment period, ranging from 12 percent per year in year 1 to 6 percent growth in year 10. The primary 

driver for DSM programs in Saskatchewan is the economic incentive or the difference in cost between providing the DSM 

program and the cost of serving the load. Increases in DSM will come from growth of existing and new programs. DSM savings 

are counted as a load modifier and are netted from the load forecast. Saskatchewan considers DR to be a capacity resource 

used for peak shaving and has energy-limited contracts in place with a number of customers to provide this service.

Saskatchewan will continue to initiate new economically viable DSM programs and will monitor and expand (if required) the 

DR programs.

The primary sources of fuel in Saskatchewan are coal, hydro, and natural gas. Throughout the assessment period, a total 

capacity of 1,631 MW (nameplate) of Future‐Planned resources are projected to come on‐line. This total consists of 250 MW 

of refurbished coal, 765 MW of gas, 530 MW (nameplate) of wind, 36 MW of biomass resources, and 50 MW of additional 

hydro resources. Projected unit retirements during the long-term planning horizon include a 79 MW natural gas facility, two 

139 MW coal facilities, an 11 MW wind facility, and a 95 MW natural gas facility. Saskatchewan manages unit retirements 

and negative impacts to capacity within its resource planning process and allows adequate time for new supply resources to 

be put in service to meet the reliability requirements during the assessment period.

Saskatchewan plans for 10 percent of wind nameplate capacity to be available to meet summer peak demand and 20 percent 

of wind nameplate capacity to be available to meet winter peak demand. The wind available to meet peak requirements is 

based on the historical actual wind generation over a four‐hour period during the peak for each day for the entire year. 

Historical data was used for each wind installation from the time it was first in service. On‐peak expected values for hydro 

assume nameplate net generation less expected seasonal derates due to water conditions. Saskatchewan plans for 100 

percent of biomass nameplate capacity to be available to meet demand, based on a base‐load contract. 

Saskatchewan has not identified any impacts on operational procedures due to integrating variable resources over the 

assessment period. Saskatchewan performs reviews of operational procedures when planning to integrate variable resources. 

The addition of VERs in the future may require System Operators to be able to curtail these resources, or to have additional 

fast-ramping capacity available from other resources to follow the intermittency of the variable resource. 
MRO-SaskPower

NERC | 2014 Long-Term Reliability Assessment | November 2014

49

Saskatchewan does not rely on capacity transactions for reliability assessments unless there is a Firm contract for both the 

supply source and transmission. Saskatchewan anticipates having a Firm import contract for 25 MW from winter 2015 to 

spring 2022. There are no Firm exports planned for the assessment period. Saskatchewan does not rely on emergency imports 

to meet its demand.

Transmission Outlook and System Enhancements

The following are the top transmission projects that relate to the maintenance of or enhancement to reliability during the 

near-term planning horizon of the assessment period for Saskatchewan: 

 Approximately 300 km of 138 kV transmission line in the northern region of Saskatchewan.

 Approximately 110 km of 230 kV transmission line in the east-central region of Saskatchewan.

 Approximately 225 km of 230 kV transmission, 225 km of 138 kV transmission, and salvage of 135 km of 138 kV line 

in the southwest region of Saskatchewan.

 Approximately 100 km of 230 kV transmission line in the southeast region of Saskatchewan.

 Seven new 230-138 kV auto-transformers in the southeast region of Saskatchewan.

These projects are heavily dependent on load growth. Delays are assessed when indicated, and interim measures (if required) 

are implemented to ensure system reliability is not impacted

For the assessment period, Saskpower has been identified that the local Swift Current area (southwest region of

Saskatchewan) is reactive power-limited in the long term. To address this, a static var system (SVS) is planned in the nearterm planning horizon.

One under-voltage load shedding (UVLS) scheme is planned in the near-term planning horizon, in the Tantallon area in the 

southeastern region of the province. This scheme will be installed to mitigate potential low voltages under certain generation 

dispatch scenarios caused by local N-1 outages (until planned transmission reinforcements into Tantallon are in place) and a 

few local N-2 outages in the southeastern region of the province. The planned UVLS scheme targets less than 100 MVA of 

load to be shed in stages. A new 230 kV transmission line is proposed in the near-term planning horizon that will reinforce 

the Tantallon-area voltage. The UVLS scheme will then be used to mitigate potential low voltages for N-1-1 and N-2 outages 

under certain generation dispatch scenarios.

The following conceptual Special Protection Systems (SPS) in Saskatchewan address potential generation deliverability 

concerns in the near-term planning horizon in the local area caused by N-2 outages. Once local area system reinforcements 

are installed to mitigate the N-2 contingency concerns, these protection systems may still remain installed to address more 

extreme operating scenarios:

 Estevan Area (southeastern region): This protection system is planned to be temporary until projected industrial 

load growth in the region materializes.

 Nipawin Area (east-central region): This protection system is planned to be permanent for the assessment period.

 Melfort Area (east-central region): This protection system is planned to be temporary until a planned 110 km, 230 

kV transmission line is in service in the region.

Long-Term Reliability Issues

Resource adequacy and operational concerns can apply for various reasons, including extreme weather events, hydro 

conditions, standards, Demand Response programs, variable generation, and other unit conditions. 

Operation of the Saskatchewan system would be performed on a best-effort basis under extreme weather events. Demand 

would be offset by planning reserves and external markets. If necessary, operational measures include Demand Response, 

Interruptible Load contracts, public appeals, and rotating outages.
MRO-SaskPower

NERC | 2014 Long-Term Reliability Assessment | November 2014

50

Saskatchewan hydro resource planning is based on median flow conditions utilizing historical data. Most of Saskatchewan’s 

hydro facilities have some form of storage and are capable of achieving near-full-load output for some period of time under 

most operating conditions.

Demand Response (DR) programs are contracted on an as-needed basis. If additional DR programs are required, 

Saskatchewan will actively solicit additional DR customers.

One of the largest factors for operational concerns is the addition of variable resources,such as wind and solar. Saskatchewan 

performs wind integration studies and is in the process of developing a 10-year wind power strategy. The amount of load that 

is offset by DERs or BTMG is reflected in the load forecast used for reliability assessments. It is not anticipated that 

Saskatchewan will encounter any long-term reliability impacts due to DERs or BTMG.

Typically, a significant amount of unit maintenance (partial and total unit outages) is planned for the shoulder periods in 

Saskatchewan. If reliability issues are identified during a shoulder period, unit maintenance will be rescheduled. Fuel 

disruptions are minimized as much as possible by system design practices, and Saskatchewan has a diverse energy mix of 

resources. Coal resources have Firm contracts and are mine-to-mouth, and stockpiles are maintained at each facility in the 

event that mine operations are unable to meet the required demand of the generating facility. Natural gas resources have 

Firm transportation contracts with large natural gas storage facilities located within the province backing those contracts up.

Hydro facilities/reservoirs are fully controlled by Saskatchewan, and long-term hydrological conditions are monitored.

Canadian federal regulations for CO2 emissions have been finalized and lay out the requirements and timelines for existing 

coal-fired generation for the reduction of GHG. These regulations could impact the direction taken on carbon capture and 

storage technology and new natural gas generation. These impacts will have a cascading effect on many other significant 

areas, including current and projected contracts for future supply of coal and natural gas. Provincial regulations are currently 

being developed, and an equivalency agreement between the provincial and federal governments may be created to allow 

greater flexibility to meet GHG regulations. Saskatchewan is working with the provincial government in developing the 

equivalency agreement.

Development and finalization of federal regulations to limit CO2 from natural-gas-based electricity generation could cause 

Saskatchewan to modify operational use of existing gas units in order to remain compliant. Pending federal natural gas rules 

for electricity generation will impact the timing and nature of capital projects, potential retirements, or new energy decisions.

These regulations are constantly monitored and are included in resource adequacy assessments. Saskatchewan plans to 

include sufficient time to perform retrofits or replacement to meet required regulations. Saskatchewan has not yet 

experienced any reliability issues related to GHG regulations and is expected to effectively mitigate any future issues related 

to them.

The requirement to reduce NOx, SO2, and CO2 emissions for both coal and natural gas facilities will require ongoing resource 

planning to ensure that retrofitting or the addition of new emission control equipment is done in a timely manner. The 

parasitic load for emission equipment is substantial. It must be included in determining net outputs from generation facilities 

and is dependent on the intensity limits for emission reductions. Saskatchewan is working with both the provincial and federal 

governments on emission regulations and equivalency agreements.

Saskatchewan will have approximately 8.5 percent (capacity) of wind integration by 2017 and is looking at adding more in 

the long term. The addition of VERs may have operational impacts that need to be studied to determine the power system 

effects to both Saskatchewan and neighboring jurisdictions. Depending on the makeup of the future generation resources, 

variable resources may need to be curtailed, or other generation sources may need to come on-line to allow for the sudden 

changes in output.
NERC | 2014 Long-Term Reliability Assessment | November 2014

51

NPCC-Maritimes

Assessment Area Overview

The Maritimes Assessment Area is a winter-peaking NPCC subregion that contains two BAs. It is comprised of the Canadian provinces of 

New Brunswick, Nova Scotia, and Prince Edward Island, and the northern portion of Maine, which is radially connected to the New 

Brunswick power system. The area covers 58,000 square miles, with a total population of 1.9 million people.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

20 percent

Load Forecast Method

Coincident; 50/50 forecast

Peak Season

Winter

Planning Considerations for Wind Resources

Estimated capacity is derived from a combination of mandated 

capacity factors and reliability impacts.

Planning Considerations for Solar Resources

N/A

Footprint Changes

A conceptual tie line to the Canadian province of Newfoundland 

and Labrador could potentially impact the Maritimes footprint.

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 5,477 5,513 5,508 5,493 5,466 5,434 5,421 5,420 5,425 5,427

Demand Response 247 252 252 252 251 251 251 251 251 251

Net Internal Demand 5,230 5,261 5,256 5,241 5,214 5,183 5,170 5,169 5,174 5,176

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 6,676 6,680 6,527 6,527 6,527 6,527 6,527 6,527 6,527 6,527

Prospective 6,820 6,824 6,671 6,824 6,824 6,824 6,824 6,824 6,824 6,824

Adjusted-Potential 6,820 6,824 6,671 6,824 6,824 6,824 6,824 6,824 6,824 6,824

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 27.66% 26.97% 24.19% 24.53% 25.18% 25.93% 26.25% 26.28% 26.16% 26.11%

Prospective 30.42% 29.71% 26.93% 30.20% 30.88% 31.67% 32.00% 32.03% 31.90% 31.85%

Adjusted-Potential 30.42% 29.71% 26.93% 30.20% 30.88% 31.67% 32.00% 32.03% 31.90% 31.85%

Reference Margin Level 20.00% 20.00% 20.00% 20.00% 20.00% 20.00% 20.00% 20.00% 20.00% 20.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 401 366 220 238 270 308 323 325 319 316 

Prospective 545 511 364 535 567 605 620 622 616 613 

Adjusted-Potential 545 511 364 535 567 605 620 622 616 613 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

10%

15%

20%

25%

30%

35%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-0.20

-0.15

-0.10

-0.05

0.00

0.05

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Renewables
NPCC-Maritimes

NERC | 2014 Long-Term Reliability Assessment | November 2014

52

Demand, Resources, and Reserve Margins

The Reference Margin Level for the Maritimes Area is 20 percent and has not changed since the 2013LTRA. During summer 

and winter peak load periods, the Anticipated, Prospective, and Adjusted Potential Reserve Margins remain above the 

Reference Margin Level during the assessment period.

Compared to the 2013LTRA, the aggregated load growth rate for the combined sub-areas is practically unchanged for both 

the summer and winter seasonal peak load periods. Overall, the Maritimes Area’s 3,500 MW summer peak and 5,500 MW 

winter peak loads are both expected to decline slightly during the 10-year assessment period. Current and projected effects 

of energy efficiency are incorporated directly into the load forecast for each of the areas. Direct Control Load Management 

(DCLM) in New Brunswick (NB) is intended to shift peak load into lower load periods and this program is directly embedded 

in the load forecast (reported as energy efficiency).

90 DCLM in NB is expected to rise from approximately 20 MW in 2015 to 

about 240 MW by the end of the assessment period. The amount of Interruptible Load in 2015 will be approximately 335 MW 

during the summer and 240 MW during the winter, increasing by about 10 MW/year over the assessment period.

Planned capacity additions include 231 MW (28 MW during the peak) of wind capacity, along with a 10 MW biomass plant, 

both in Nova Scotia (NS). These additions will have virtually no reliability impacts, due to their smaller size. A 153 MW 

generator in NS is expected to be retired in October 2017. This retirement depends on the planned construction of an 

undersea HVDC cable between NS and the Canadian Province of Newfoundland and Labrador as part of the Muskrat Falls 

hydro-electric generation development. NS plans to offset the retirement of the thermal unit with a 153 MW import of hydro 

capacity from Muskrat Falls.

Currently there are no Firm capacity contracts between the Maritimes Area and neighboring areas. While the Maritimes Area 

includes 300 MW of tie benefits in its resource adequacy analyses, it is not dependent on these capacity transactions or 

emergency imports from neighboring areas to meet its Reference Margin Level. Any such transactions are coordinated 

through NPCC working groups, which include members from all neighboring areas. 

Transmission Outlook and System Enhancements

One major new transmission line addition in the Maritimes Area is planned for 2017. Development of the aforementioned 

Muskrat Falls Generation Project in the Canadian Province of Newfoundland and Labrador in 2017 will see the installation of 

a High-Voltage Direct Current (HVdc) undersea cable link (Maritime Link) between that province and NS.

The Eel River, NB HVdc interconnection with the Canadian Province of Québec will be refurbished during 2014. This interface 

provides import and export capability up to 350 MW with the Province of Québec and contributes to frequency response in 

the Maritimes Area. An additional 230 kV breaker installation will allow the separation of supplies to two 230/138 kV 

transformers in the substation at Eel River. 

The construction periods for the planned projects mentioned above are all short and can be scheduled during times that will 

not significantly affect the reliability of the area. Capacity imports associated with the Maritime Link Project and the 

retirement of a comparable-sized unit will be timed to coincide so that the project will not have an impact on overall reliability.

Long-Term Reliability Issues

The hydroelectric power supply system in the Maritimes Area, with a capacity of approximately 1,330 MW, is predominantly 

run-of-the-river as opposed to storage based. Large quantities of energy cannot be held in reserve to stave off drought 

conditions. If such conditions occur, the hydro system would still be used to follow load in the area and respond to sudden 

short-term capacity requirements. Thermal units would be used to keep the small storage capability of the hydro systems 

usable only for load-following or peak supply. The Maritimes Area is not overly reliant on wind capacity to meet resource 

adequacy requirements. Neither (1) the lack of wind during peaks, (2) very high wind speeds, nor (3) icing conditions that 

 

90 DCLM for the Maritimes area is in the early stages of development. Future effects are included in Energy Efficiency until they can be clearly identified 

and itemized in forecasts.
NPCC-Maritimes

NERC | 2014 Long-Term Reliability Assessment | November 2014

53

would cause wind farms to suddenly shut down should affect the dependability of supply to the area, as ample spinning 

reserve is available to cover the loss of the largest baseload generator in the area. The latter situation is mitigated further by 

wide geographic dispersal of wind resources across the area.

RPSs have led to the development of substantially more wind generation capacity than any other type of renewable 

generation. Reduced frequency response associated with wind generation may, with increasing levels of wind generation in 

the future, require displacement with conventional generation during light load periods. With the significant amount of largescale wind energy currently being balanced on the NB system, the next phase of renewable energy development in NB will 

focus on smaller-scale projects with a particular emphasis on non-variable forms of generation, such as wood-based biomass. 

In NS, the Maritimes Link project will displace several conceptual wind farm installations with renewable hydro resources and 

should help mitigate potential and related frequency response issues.

The Maritimes Area has a diversified mix of capacity resources fueled by oil, coal, hydro, nuclear, natural gas, wind (derated), 

dual-fuel oil/gas, tie benefits, and biomass, with no one type feeding more than 26 percent of the total capacity in the area. 

There is not a high degree of reliance upon any one type or source of fuel. Resource planners in the Maritimes Area do not 

anticipate that fuel disruptions will pose significant challenges to resource adequacy during the assessment period. This 

resource diversification also provides flexibility to respond to any future environmental issues, such as potential restrictions 

to GHG emissions.

Load growth in the southeastern corner of the NB sub-area, though not specifically identified in the load projections, has 

outpaced the rest of that sub-area. Planners are monitoring transmission loads and voltages in the area to ensure reliability 

is not affected. No reinforcements have been planned at this time. DSM programs aimed at reducing and shifting peak 

demands and any future potential imports to NB from NS could reduce transmission loads in the southeastern NB area. On 

the whole, the NB sub-area expects a slight decline in load during the assessment period. The impact on the resource 

adequacy LOLE value is captured by modeling a reduction in tie transfer capabilities between sub-areas. The NPCC - 2013 

Maritimes Area Comprehensive Review of Resource Adequacy91 showed that after transfer levels were reduced from 300 MW 

to 150 MW, LOLE values do not exceed the NPCC target limit of 0.1 days per year of resource inadequacy. The Reference 

Margin Levels will not be affected by this issue. 

The addition of renewable resources, particularly in NS, is an emerging issue in the Maritimes Area within the assessment 

period. Nova Scotia’s Renewable Electricity Standard (RES) is seeking to displace significant amounts of fossil-fired generation 

with renewable resources. By 2015, 25 percent of the province’s electricity sales (energy) will be supplied by renewable 

energy sources, and by 2020 this number increases to 40 percent. Increasing amounts of renewable resources could affect 

BPS reliability if variable or low-mass slow speed units are added without considering the reduction of frequency response 

after system contingencies or transmission enhancements to prevent voltage or overload problems. The process of 

completing system impact studies prior to interconnecting new generation should identify whether the emergence of any of 

these issues could limit the operation of or amount of new renewable generation added to the system on a case-by-case 

basis.

Because of the relative size of the largest generating unit in the Maritimes Area compared to its aggregated load, the area 

carries substantial reserve capacity. Generators use a diverse mix of fuel types with the result that the Maritimes Area is not 

overly reliant on any particular fuel to meet its load. The area is strongly interconnected with neighboring areas via highcapacity transmission lines but is not dependent on these areas to supply area load. As a result, LOLE analysis suggests that 

even with reasonable foreseeable contingencies—including load forecast uncertainty, extreme weather, fuel disruptions, and 

generator and transmission interruptions—the Maritimes Area load will be reliably supplied for the 10 years covered in this 

report.

 

91 NPCC - 2013 Maritimes Area Comprehensive Review of Resource Adequacy. 
NERC | 2014 Long-Term Reliability Assessment | November 2014

54

NPCC-New England

Assessment Area Overview

ISO New England (ISO-NE) Inc. is a regional transmission organization (RTO) serving Connecticut, Maine, Massachusetts, New Hampshire, 

Rhode Island, and Vermont. It is responsible for the reliable day-to-day operation of New England’s bulk power generation and transmission 

system and also administers the region’s wholesale electricity markets and manages the comprehensive planning of the regional BPS. The 

New England regional electric power system serves approximately 14.5 million people over 68,000 square miles.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

The Installed Capacity Requirement (ICR) results in a Reference 

Margin Level of 15.7 percent in 2015, declining to 14.3 percent in 

2017 and remaining at that level for the duration of the period.

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Summer

Planning Considerations for Wind Resources

5 percent of the total

Planning Considerations for Solar Resources

Seasonal claimed capability

Footprint Changes

N/A

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 26,930 27,291 27,521 27,677 27,782 27,911 28,028 28,167 28,298 28,430

Demand Response 1,167 944 994 994 994 994 994 994 994 994

Net Internal Demand 25,763 26,347 26,527 26,683 26,788 26,917 27,034 27,173 27,304 27,436

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 31,880 33,052 31,529 31,529 31,529 31,529 31,529 31,529 31,529 31,529

Prospective 31,887 33,286 31,904 32,446 32,463 32,463 32,463 32,463 32,463 32,463

Adjusted-Potential 31,887 33,286 31,904 32,446 32,463 32,463 32,463 32,463 32,463 32,463

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 23.75% 25.45% 18.85% 18.16% 17.70% 17.13% 16.63% 16.03% 15.47% 14.92%

Prospective 23.77% 26.34% 20.27% 21.60% 21.18% 20.60% 20.08% 19.47% 18.89% 18.32%

Adjusted-Potential 23.77% 26.34% 20.27% 21.60% 21.18% 20.60% 20.08% 19.47% 18.89% 18.32%

Reference Margin Level 15.70% 15.10% 14.30% 14.30% 14.30% 14.30% 14.30% 14.30% 14.30% 14.30%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 2,073 2,727 1,208 1,030 910 762 629 470 320 169 

Prospective 2,080 2,961 1,583 1,947 1,844 1,697 1,563 1,404 1,254 1,103 

Adjusted-Potential 2,080 2,961 1,583 1,947 1,844 1,697 1,563 1,404 1,254 1,103 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

10%

12%

14%

16%

18%

20%

22%

24%

26%

28%

30%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Petroleum Natural Gas

Renewables Hydro Pumped Storage
NPCC-New England

NERC | 2014 Long-Term Reliability Assessment | November 2014

55

Demand, Resources, and Planning Reserve Margins

New England’s (ISO-NE) Reference Margin Level is based on the capacity needed to meet the NPCC one-day-in-10-years LOLE 

resource planning reliability criterion. The amount of capacity needed—referred to as the Installed Capacity Requirement 

(ICR)—varies from year to year depending on expected system conditions. The ICR, which is calculated three years in advance 

for each Forward Capacity Market (FCM) auction, results in a Reference Margin Level of 15.7 percent in 2015, 15.1 percent 

in 2016, and 14.3 percent in 2017. In this assessment, the last calculated Reference Margin Level (14.3 percent) is applied for 

the remaining years.

ISO-NE’s Anticipated Reserve Margin during the annual peak reflects the Seasonal Claimed Capability of all ISO-NE generators, 

as well as demand resources and imports that have Capacity Supply Obligations (CSOs) as a result of the FCM auctions. In the 

2015 summer, ISO-NE’s Anticipated Resources amount to 31,880 MW, which results in an Anticipated Reserve Margin of 23.8 

percent of the Net Internal Demand of 25,763 MW. The Anticipated Reserve Margin remains above the 14.3 percent 

Reference Margin Level through the entire assessment period.

The 2015 summer peak Total Internal Demand, which takes into account 1,685 MW of passive demand resources, or energy 

efficiency, is 26,930 MW. There has been no substantial change in the forecast since last year.

DSM in the ISO-NE BPS includes both active and passive demand resources. Active demand resources consist of real-time DR

and real-time emergency generation, which can be activated with the implementation of ISO-NE Operating Procedure No. 4 

– Action during a Capacity Deficiency (OP-4). Active demand resources are based on the CSOs obtained through ISO-NE’s FCM 

three years in advance. The CSOs decrease slightly from 1,167 MW in 2015 to 944 MW in 2016 and then increase to 994 MW 

in 2017. Since there are no further auction results, the CSOs are assumed to remain at the same level through the end of the 

reporting period.

Passive demand resources (i.e., energy efficiency and conservation) include installed measures (e.g., products, equipment, 

systems, services, practices, and strategies) on end-use customer facilities that result in additional and verifiable reductions 

in the total amount of electrical energy used during on-peak hours. Passive DR is also secured by means of the FCM. However, 

ISO-NE has developed an energy efficiency forecasting method that takes into account the potential impact of growing energy 

efficiency and conservation initiatives in the region to project the amount of energy efficiency beyond the years when the 

FCM CSOs have already been procured. Energy efficiency has generally been increasing and is projected to continue growing 

throughout the study period. The amount of energy efficiency in 2015 is 1,685 MW and is projected to increase to nearly 

3,500 MW by 2024.

Active demand resources are treated like generating resources in ISO New England and are dispatched by ISO operators when 

they are needed to meet load and operating reserve requirements. A number of retirements are expected to take place in 

the region within the next three years. Salem Harbor Units 3 and 4, which are coal- and oil-fired units with a combined capacity 

of 587 MW, were scheduled to retire by June 1, 2014. Salem Harbor Units 1 and 2, which were coal-fired units with a total 

capacity of 158 MW, were previously retired in December 2011. As a result of these retirements, upgrades to five transmission 

lines in the North Shore area (northwest of Boston) were identified as being needed to address immediate reliability concerns. 

Those transmission upgrades have been placed in service. The capacity lost with the retirement of Salem Harbor is expected 

to be replaced by the new Footprint Power 674 MW generating plant, which is to be located at the Salem Harbor site. 

In August 2013, the Vermont Yankee nuclear plant (619 MW) announced that it would be shutting down by the end of 2014. 

Later in 2013, ISO-NE was notified that an additional 1,877 MW planned to retire on June 1, 2017. This total consisted of five 

coal- and oil-fired resources representing 1,535 MW from the Brayton Point Station and three oil-fired resources representing 

342 MW from Norwalk Harbor Station. 

Even with these retirements, the reserve margin is not expected to fall below the 14.3 percent Reference Margin Level during 

the assessment period. However, since new environmental requirements may result in the retirement of additional 

resources, the ISO is working with stakeholders to identify issues and find the means of meeting future capacity needs. 
NPCC-New England

NERC | 2014 Long-Term Reliability Assessment | November 2014

56

Approximately 6,900 MW of proposed generation is in the ISO Generator Interconnection Queue. Market incentives are 

under development to increase resource development where and when needed.

By design, the level of the ICR specified for New England could necessitate the use of specific OP-4 actions because the ICR 

calculation includes capacity and accounts for the load relief these actions provide. Operable capacity study results show that 

the need for load and capacity relief by OP-4 actions will be approximately 2,600 MW during extremely hot and humid 

summer peak load conditions. This amount is likely achievable through OP-4 actions by depleting operating reserves, 

scheduling emergency transactions with neighboring systems, operating real-time emergency generators, and implementing 

five percent voltage reductions.

Preserving the reliable operation of the system will become increasingly challenging with potential retirements and the need 

for operating flexibility, particularly in light of the reliance on natural gas resources. These factors are expected to increase 

the need for reliable resources, especially those able to provide operating reserves and ramping capabilities. To begin 

addressing this need, the ISO has procured additional 10-minute reserves and replacement operating reserves.

These challenges will be addressed over the long term through the Strategic Planning Initiative.92 As part of this initiative, the 

ISO has been actively collaborating with stakeholders on comprehensive near- and long-term rule changes across the region’s 

suite of energy, reserve, and capacity markets. Proposed enhancements to the FCM include modification of the zonal 

structure used in the capacity market, flexibility in Energy Market offers, and a “pay-for-performance” mechanism in the FCM 

that will create stronger financial incentives for capacity suppliers to perform when called on during periods of system stress.

New England has witnessed significant growth in the development of solar photovoltaic (PV) resources over the past few 

years, and continued growth of PV is expected. Solar PV resources installed in New England are predominantly BTMG, not 

visible to ISO Operations in real time. An estimated one-third of these projects are registered in ISO’s energy market as 

Settlement-Only Resources. ISO-NE is not directly involved in the interconnection of most of these resources and has 

therefore not traditionally been aware of when and where they are installed. ISO-NE recently formed a stakeholder working 

group to increase its understanding of development trends of PV and other DERs, and to develop a forecast of PV over the 

next 10 years. At the end of 2013, 500 MWac of PV was installed in New England, and projections indicate that over 1,800 

MWac will be added by 2023.

In January 2014, ISO-NE began incorporating wind forecasting into its processes, scheduling, and dispatch services. With wind 

forecast integration complete, the ISO will be working toward the full economic dispatch of wind resources in phase 2 of this

project. The ISO will continue to analyze wind integration issues and work with stakeholders to address the issues challenging 

the wind interconnection process and the performance of the system with wind resources in locally constrained areas. New 

England is applying advanced technologies, including FACTS and HVdc, phasor measurement units (PMUs), and smart meters, 

which may be used to provide the regulation and reserve services required to reliably integrate variable renewable resources.

Currently there is only 101 MW of on-peak wind capacity in New England, and only 185 MW (on-peak capacity) of future 

planned wind additions during the study period.

Given the embedded nature of most PV development in New England—projects are interconnected to the distribution system

and can neither be directly observed nor dispatched by the regional System Operator—the influence of increased amounts 

of PV will introduce increased variability and uncertainty to the system and eventually will have an impact on system 

operations (e.g., result in the need for increased reserve, regulation, and ramping). As such, new forecasting techniques 

eventually will be required to account for PV generation appropriately. To prepare for this, ISO-NE is actively tracking the 

growth of PV in the region, monitoring its impact on operational load forecasting performance, and researching forecasting 

options that may serve as short- and/or long-term solutions.

 

92 ISO-NE Strategic Planning Initiative Key Project. 
NPCC-New England

NERC | 2014 Long-Term Reliability Assessment | November 2014

57

Firm summer capacity imports are based on FCM CSOs, which amount to 1,642 MW in 2015 and decrease to 1,267 MW in 

2017. Firm transactions beyond 2017 are held constant at the value in 2017. Only Firm imports are reported in this 

assessment. However, in addition to capacity imports that have CSOs, external transactions can participate in the day-ahead 

and real-time energy markets. In past years, actual imports during the peak have been significantly higher than the CSOs. For 

example, in 2013 the imports to New England from New York, New Brunswick, and Quebec at the time of the peak demand 

totaled 3,172 MW, or 1,969 MW more than the CSO of 1,203 MW. During the assessment period, there is a Firm capacity sale 

to New York (Long Island) of 100 MW that is expected to be delivered via the Cross-Sound Cable. 

In the case of inadequate 10-minute operating reserves, ISO-NE can implement an OP-4 action to arrange for the purchase 

of up to 1,000 MW of available emergency capacity and energy, or energy only (if capacity backing is not available), from 

market participants or neighboring control areas. ISO-NE coordinates with other Assessment Areas to evaluate changes to 

the transmission system that would have an impact on import and export capabilities, and to determine a safe and reliable 

transfer limit if changes are needed. For long-term studies, ISO-NE confirms imports and exports through NPCC working group 

studies.

Transmission Outlook and System Enhancements

Several future transmission projects coming on-line during the assessment period are important to the continuation of, or 

enhancement to, system or sub-area reliability. The major projects under development in New England include the Maine 

Power Reliability Program (MPRP) and the New England East–West Solution (NEEWS). The new paths that are part of MPRP 

(many components of which are under construction) will provide the basic infrastructure necessary to increase the ability to 

move power from New Hampshire into Maine and improve the ability of Maine’s transmission system to move power into 

the local load pockets as necessary. NEEWS consists of a series of projects that will improve system reliability in areas including 

Springfield, Massachusetts, and Rhode Island, and increase total transfer capability across the New England east-to-west and 

west-to-east interfaces.

New smart grid technologies such as FACTS are being used in New England to improve the electric power system’s 

performance and operating flexibility. In addition, several investor-owned and municipal utilities in New England are 

conducting smart grid pilot programs or projects ranging from smart meter deployments to full-scale direct load control and 

distribution automation projects. ISO-NE anticipates that these projects may lead to more significant smart grid assets 

becoming available for potential utilization during the assessment period.

Long-Term Reliability Issues

If New England experiences extreme summer weather that results in 90/10 peak demands or greater, ISO-NE still should have 

enough operable capacity available to reliably manage the BPS. However, if supply-side outages diminish New England’s 

operable capacity to serve these 90/10 peak demands, ISO-NE will be able to invoke OP-4 to meet the demand and maintain 

the operating reserve requirement.

RPSs mandate that by 2023, energy efficiency and renewable resources such as wind and solar must supply approximately 

one-third of the projected electric energy in New England. Possible solutions for meeting the regional RPSs include developing 

the renewable resources already in the ISO generator interconnection queue; importing renewable resources from adjacent 

balancing authority areas; building new renewable resources in New England not yet in the queue; and using BTMG projects 

and eligible renewable fuels, such as biomass, at existing generators. 

Concerns exist over the resultant impacts from compliance with state RPSs and the potential build-out of these new 

renewable resources. Because of concerns over the increasing amounts of wind capacity, ISO-NE completed a major wind 

integration study that identified the detailed operational issues of integrating large amounts of wind resources into the New

England power grid. The New England Wind Integration Study (NEWIS) found that the large-scale integration of wind 

resources is feasible, but resource planners will need to continue addressing a number of issues, including the development 

of an accurate means of forecasting wind generation outputs. As a result of that recommendation, ISO-NE implemented a 
NPCC-New England

NERC | 2014 Long-Term Reliability Assessment | November 2014

58

centralized wind power forecasting service. The addition of variable energy resources, particularly wind and solar, will likely 

grow with time, hence increasing the need for flexible resources to provide operating reserves as well as other ancillary 

services, such as regulation and ramping. 

Since ISO-NE’s Demand Response resources are treated as capacity and are procured three years in advance in its Forward 

Capacity Auctions, approximately 1,000 MW of active DR are expected to be available. As previously noted, active DR can be 

triggered by ISO-NE in real time under OP-4 to help mitigate a capacity deficiency by reducing the peak demand. Over the 

past three years, the actual performance of these resources during summer peak period OP-4 events has ranged from 95 to 

100 percent, and winter response rates have ranged from 75 to 100 percent.

PV resources (and to a lesser extent other types of DG resources) are rapidly developing in New England and predominantly 

are not directly observable or controllable by ISO-NE. Because of the differences between the state-jurisdictional 

interconnection standards that apply to most PV resources and the FERC-jurisdictional standards that apply to larger 

conventional generators, PV exhibits different electrical characteristics during system conditions typical of grid disturbances. 

ISO-NE is working with the New England states, distribution utilities, IEEE, and various international experts to ensure that 

the future interconnection standards for PV (and other inverter-interfaced DG resources) better coordinate with broader 

system reliability requirements. 

Environmental compliance obligations for generators due to existing and pending state, regional, and federal environmental 

requirements are likely to impose operational limits on new and existing generators but pose only a limited retirement risk 

and lower reliability impacts compared to earlier assessments. The lowered retirement risk is due in large part to the flexibility 

that the EPA has provided in its cooling water rule and MATS, recognizing the reliability value that low-capacity-factor fossil 

steam generators provide in maintaining system fuel diversity.

Up to 12.1 GW of generating capacity in New England that currently utilizes once-through cooling, including a subset of units 

with larger withdrawal capacities, may potentially need to convert closed-cycle cooling systems. 

Approximately 7.9 GW of existing coal- or oil-fired capacity in New England is subject to MATS. Most affected generators in 

New England are equipped with required air toxics control devices due to earlier compliance with state air toxics regulations

in New England. No retirements have been announced or are expected in New England due to MATS. However, a one-year 

compliance extension request has been sought by a generator for less than 100 MW of affected coal-fired capacity. Recent 

revisions to air quality standards limit ambient concentrations of ozone, and its precursors (fine particulate matter and sulfur 

dioxide) are expected to require additional emissions reductions from fossil-fired generators.

New England faces a number of concerns for ensuring the reliability of the fuel supply, particularly the supply of natural gas 

and oil. Operating experience has exposed some vulnerabilities associated with the strategic risks of resource performance 

and flexibility and the increased reliance on natural-gas-fired capacity. During severe winter weather, such as that 

experienced in winter 2013–2014, System Operators faced challenges due to the combination of high winter loads resulting 

from cold weather, and limited natural gas and oil used to fuel generating units. In such situations, gas pipelines are often

operating at their maximum levels to supply local distribution companies (LDCs) that supply retail natural gas customers. 

Although oil-fired generators could compensate for the reduced availability of gas-fired generation, they may be limited by 

inadequate oil inventory at the beginning of winter, and securing midwinter replenishment of oil can be difficult due to 

challenges with oil transportation and availability. 

ISO-NE had implemented a winter reliability program in 2013–2014 and will initiate a modified program for the winter of 

2014–2015, along with scheduled market improvements. The major components of the planned winter reliability program 

include annual audits of dual-fuel resources; additional compensation to offset testing costs associated with restoring or 

commissioning dual-fuel capability; additional winter period Demand Response; and additional compensation for unused oil 

inventory at the end of the winter period. 
NPCC-New England

NERC | 2014 Long-Term Reliability Assessment | November 2014

59

Recent and planned improvements to the regional and interregional natural gas infrastructure provide initial steps for 

expanding the access to natural gas supply sources to meet New England’s increasing demand for natural gas for power 

generation. More expansion is required, however. Although natural gas production volumes in the northeast region are 

forecast to rise, New England cannot access the full benefit of production because of existing pipeline capacity constraints. 

The natural gas pipelines serving the region are at or near capacity, but they will not expand until customers commit to Firm 

service. A study performed by ICF International found that if one assumesthe same weather conditions as winter 2013–2014, 

winter peak-day gas supplies will be barely adequate or slightly in deficit through 2020. Outages of capacity that is not fueled 

by natural gas, such as a disruption to a nuclear unit, or unforeseen outages of natural gas infrastructure, would result in a 

serious gas supply deficit. 

An emerging reliability issue currently being addressed by ISO-NE is the significant growth of DG resources in New England. 

Because PV resources constitute the largest segment of DG resources throughout New England, the ISO’s analysis of DG 

focuses exclusively on the impact of additional distributed PV. To help address the interrelated questions of exactly how much 

additional PV is projected in the ISO’s 10-year planning horizon and what impact this future PV could have on the regional 

power grid, the ISO, in conjunction with stakeholders, endeavored to create a forecast of all future PV resources. In 

September 2013, the ISO established the Distributed Generation Forecast Working Group (DGFWG) to assist its development 

of a DG forecast and provide a forum to discuss DG integration issues. 

Due to the complexities associated with creating a PV forecast, the ISO began with an interim PV forecast that was limited to 

PV that results from state policies. The PV estimates are based on state-by-state policy initiatives, with discounts to account 

for the uncertainty of existing and future policies. The ISO is working with the DGFWG to find ways to improve on the forecast 

in future years.

Results of the forecast will inform various ISO system planning functions. For example, the ISO intends to use data from the 

DG forecast in transmission studies, new generator interconnection studies, and economic studies. The ISO will work with 

stakeholders to explore how the DG forecast may potentially be used in these planning analyses and other market-related 

assessments. These may include such tasks as the development of the ICR.

The growth in DG presents some challenges for grid operators and planners. Challenges for the ISO include: (1) a limited 

amount of data concerning DG resources, including their size, location, and operational characteristics; (2) a current inability 

to observe and control DG resources in real time; (3) a need to better understand the impacts of growing DG on system 

operations, including ramping, reserve, and regulation requirements; and (4) potential reliability impacts to the regional 

power system posed by future amounts of DG resulting from existing state interconnection standards. 

Ongoing work between ISO-NE and the DGFWG will help position New England to best integrate rapidly growing DG resources 

in a way that maintains reliability and allows the states to realize the public policy benefits they have identified as the basis 

for their DG programs.
NERC | 2014 Long-Term Reliability Assessment | November 2014

60

NPCC-New York

Assessment Area Overview

The New York Independent System Operator (NYISO) is the only BA within the state of New York (NYBA). The NYISO is a single-state ISO 

that was formed as the successor to the New York Power Pool—a consortium of the eight IOUs—in 1999. The NYISO manages the New 

York State transmission grid, encompassing approximately 11,000 miles of transmission lines over 47,000 square miles and serving the 

electric needs of 19.5 million New Yorkers. New York experienced its all-time peak load of 33,956 MW in the summer of 2013.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

The New York State Reliability Council (NYSRC) Installed Reserve 

Margin (IRM) of 17 percent extends through April 2015. Because 

this margin will be reassigned in 2015, NYISO will use the default 

Reference Margin Level of 15 percent.

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Summer

Planning Considerations for Wind Resources

Modeled with a 17 percent capacity factor

Planning Considerations for Solar Resources

Modeled with a 65 percent capacity factor

Footprint Changes

N/A

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 34,066 34,412 34,766 35,111 35,454 35,656 35,890 36,127 36,369 36,580

Demand Response 1,189 1,189 1,189 1,189 1,189 1,189 1,189 1,189 1,189 1,189

Net Internal Demand 32,877 33,223 33,577 33,922 34,265 34,467 34,701 34,938 35,180 35,391

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 38,311 38,330 37,980 37,980 37,985 37,985 37,985 37,985 37,985 37,985

Prospective 41,715 42,691 42,702 43,217 43,228 43,228 43,228 43,228 43,228 43,228

Adjusted-Potential 41,715 42,691 42,702 43,217 43,228 43,228 43,228 43,228 43,228 43,228

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 16.53% 15.37% 13.11% 11.96% 10.86% 10.21% 9.46% 8.72% 7.97% 7.33%

Prospective 26.88% 28.50% 27.18% 27.40% 26.16% 25.42% 24.57% 23.73% 22.88% 22.14%

Adjusted-Potential 26.88% 28.50% 27.18% 27.40% 26.16% 25.42% 24.57% 23.73% 22.88% 22.14%

Reference Margin Level 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 502 123 (633) (1,030) (1,420) (1,652) (1,921) (2,194) (2,472) (2,715)

Prospective 3,907 4,485 4,088 4,207 3,823 3,591 3,322 3,049 2,771 2,528 

Adjusted-Potential 3,907 4,485 4,088 4,207 3,823 3,591 3,322 3,049 2,771 2,528 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

0%

3%

6%

9%

12%

15%

18%

21%

24%

27%

30%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-0.90

-0.70

-0.50

-0.30

-0.10

0.10

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Coal Petroleum Renewables Hydro
NPCC-New York

NERC | 2014 Long-Term Reliability Assessment | November 2014

61

Demand, Resources, and Planning Reserve Margins

The current Installed Reserve Margin (IRM) requirement for the NYBA that covers the period from May 2014 to April 2015 

(2014 Capability Year) is 17 percent. The New York State Reliability Council (NYSRC) sets this requirement annually based 

upon an annual study conducted by its Installed Capacity Subcommittee (ICS). Because the IRM will be reassigned after April 

2015, a 15 percent Reference Margin Level has been used for this long-term assessment. While the Anticipated Reserve

Margin falls below the 15 percent Reference Margin Level in 2017, the Prospective Reserve Margin remains above for all 

seasons and years of the assessment period.

The energy forecast for the downstate area is lower than that of last year due to a change in the expected relationship of 

energy growth with the economy. Whereas economic growth (based on either employment or metro area GDP) is expected 

to increase, some of the zones in the downstate area are projected to have negative energy growth, but continue to expect 

positive summer and winter peak demand growth. This decline in year-over-year energy usage is attributed to the continued 

impact of energy efficiency programs and is reflective of a recent history of negative energy usage on a weather-adjusted 

basis.

FERC approved changes to the ICAP/SCR program (Docket No. ER14-39) that became effective on March 15, 2014. These 

changes went through an extensive discussion and review process through the NYISO committees prior to filing a tariff change 

with FERC. The process to determine the ICAP value of SCR resources was modified as a result of these changes.

New York State has recently announced new initiatives in DER, BTMG, and customer-sited solar photo-voltaic power. The 

impact of solar PV has been incorporated in this year’s energy efficiency projections. It is still too early to determine the 

impact of DER on energy and summer peak, as the new policy has not yet been translated into specific targets or goals.

NYBA’s existing generation, Special Case Resources (SCR), and net imports total 41,307 MW for 2015. There are 4,579 MW of 

proposed generation included in the 2014 Load and Capacity Data Report. Of this total, 3,461 MW are fossil fuel projects, 

1,044 MW are wind turbine projects, and 22 MW are non-wind renewable energy projects. Additionally, based on publicly 

available information, 806 MW of summer capacity may be retired or mothballed by 2017.

Capacity transactions modeled in NYBA reliability studies are part of the NYBA’s resource mix to meet LOLE criteria. These 

transactions would be expected to perform on peak or any other time as needed to meet the demand. Capacity transactions 

modeled in NYBA’s assessments have met the requirements as defined in the NYBA’s tariffs. Both the NYBA and the respective 

neighboring assessment areas have agreed upon the terms of the capacity transaction. The NYBA does not rely on emergency 

imports to meet the assessment area’s Reference Margin Level. However, transfer capability is reserved on the ties with 

neighboring areas in NYBA’s planning studies to allow for emergency imports as one potential emergency operating 

procedure step in the event of a system emergency.

Transmission Outlook and System Enhancements

The Transmission Owner Transmission Solutions (TOTS) consist of three transmission projects in central New York, downstate 

New York, and New York City. TOTS is part of the Con Edison and the New York Power Authority (NYPA) filing in response to 

a November 2012 order from the New York Public Service Commission (PSC) that recognized the significant reliability needs 

that would occur if the Indian Point Energy Center (IPEC) were retired upon the expiration of IPEC’s existing licenses.

Long-Term Reliability Issues

The 2012 RNA identified new environmental regulatory programs. These state and federal regulatory initiatives cumulatively 

will require considerable investment by the owners of New York’s existing thermal power plants in order to comply. The NYBA 

has determined that as much as 33,200 MW in the existing fleet will have some level of exposure to the new regulations.

Since the publication of the RNA, the U.S. Supreme Court has consented to hear an appeal of the Cross State Air Pollution 

Rule (CSAPR). In July 2011, the EPA replaced the Clean Air Transport Rule (CATR) proposal with the finalized CSAPR. The rule 

requires significant additional reductions of SO2 and NOx emissions beyond those previously identified. The CSAPR establishes 
NPCC-New York

NERC | 2014 Long-Term Reliability Assessment | November 2014

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a new allowance system for units larger than 25 MW of nameplate capacity. Affected generators will need one allowance for 

each ton emitted in a year. In New York, CSAPR will affect 154 units that represent 25,900 MW of capacity. The EPA has 

estimated New York’s annual allowance costs for 2012 at $65 million. There are multiple scenarios that show that New York’s 

generation fleet can operate in compliance with the program in the first phase. Compliance actions for the second phase may 

include emission control retrofits, fuel switching, and new clean, efficient generation. If the EPA appeal is successful, it may 

be reasonable to expect delays in the implementation of the rule until 2016, which would place it on a schedule that is nearly 

concurrent with MATS.

The EPA finalized a regulation in February 2012 to establish emission rate standards for MATS that will limit emissions through 

the use of Maximum Achievable Control Technology (MACT) for hazardous air pollutants (HAP) from coal- and oil-fueled 

steam generators with a nameplate capacity greater than 25 MW. The majority of the New York coal fleet has installed 

emission control equipment that may place compliance within reach. The heavy oil-fired units will need to either make 

significant investments in emission control technology or switch to (or maintain) a cleaner mix of fuels in order to comply 

with the proposed standards. Given the current outlook for the continued attractiveness of natural gas compared to heavy 

oil, it is anticipated that compliance will be achieved by dual-fuel units through the use of natural gas to maintain fuel ratios 

such that the effective capacity factor on oil is less than 8. Compliance requirements begin in March 2015.

The EPA has proposed a Section 316(b) rule providing standards for the design and operation of power plant cooling systems.

This rule will be implemented by the New York State Department of Environmental Conservation (NYSDEC), which has 

finalized a policy for the implementation of this rule is known as Best Available Technology (BAT) for plant cooling water 

intake structures. This policy is activated upon renewal of a plant’s water withdrawal and discharge permit. Based upon a 

review of current information available from NYSDEC, NYISO has estimated that between 4,400 and 7,300 MW of capacity 

could be required to retrofit closed-cycle cooling systems.

The class of steam electric units constructed between 1963 and 1977 is subject to continuing emission reductions required 

by the Clean Air Act. In New York, 16 units with 8,400 MW of capacity are affected. The owners of these units have submitted 

their plans for Best Available Retrofit Technology (BART) and have received modified Title V air permits incorporating the 

final plans. The oil-fired units are proposing alternatives that include maintaining the status quo, lower sulfur fuels, and low 

NOx combustion systems. Two smaller coal plant owners have chosen to retire small boilers. The new permit limitations 

became effective January 1, 2014. No additional capacity losses are anticipated as a direct result of the implementation of 

BART.

The NYSDEC has promulgated revised regulations for the control of NOx emissions from fossil-fueled electric generating units. 

These regulations are known as NOx RACT (Reasonably Available Control Technology) for oxides of nitrogen. In New York, 254 

units with 27,800 MW of capacity are affected. Emission reductions required by these revised regulations must be in place 

by July 2014.

The Regional Greenhouse Gas Initiative (RGGI) established a cap over CO2 emissions from most fossil-fueled power plants 

with more than 25 MW in 2009. In 2012, the RGGI states undertook a program review, which concluded in February 2013.

The program review called for reducing the cap by 45,000,000 to 91,000,000 tons for 2014 and then applying annual 

reductions of 2.5 percent until 2020. A key provision to keeping the allowance and electricity markets functioning is the Cost 

Containment Reserve (CCR). If demand exceeds supply at predetermined trigger prices, an additional 10,000,000 in 

allowances would be added to the market.

The EPA has released a revised rule for final comments that is designed to limit CO2 emissions from new fossil-fueled steam 

generators and combined-cycle units. The rules are generally less stringent than the NYSDEC’s Part 251 that is applicable in 

NY. This EPA rule does not apply to simple-cycle turbines that limit their sales to the grid to less than one-third of their 

potential output.
NERC | 2014 Long-Term Reliability Assessment | November 2014

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NPCC-Ontario

Assessment Area Overview

Ontario’s electrical power system is geographically one of the largest in North America, covering an area of 415,000 square miles and 

serving the power needs of more than 13 million people. Ontario is interconnected electrically with Québec, MRO-Manitoba, states in MISO 

(Minnesota and Michigan), and NPCC-New York.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

The IESO-established Reserve Margin Requirement is applied as 

the Reference Margin Level.93

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Summer

Planning Considerations for Wind Resources

Modeled, based on historic performance and historic weather data

Planning Considerations for Solar Resources

Modeled, based on historic weather data; 30 percent for summer

Footprint Changes

N/A

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 22,726 22,535 22,344 22,301 22,272 22,170 22,479 22,609 22,616 22,541

Demand Response 567 621 695 695 695 795 945 1,095 1,295 1,495

Net Internal Demand 22,158 21,914 21,649 21,606 21,576 21,375 21,534 21,514 21,321 21,046

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 27,112 26,910 26,497 27,519 26,630 26,345 26,520 26,455 27,169 27,232

Prospective 27,112 26,910 26,497 27,519 26,630 26,345 26,520 26,455 27,169 27,232

Adjusted-Potential 27,112 26,910 26,497 27,519 26,630 26,345 26,520 26,455 27,169 27,232

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 22.36% 22.80% 22.39% 27.36% 23.42% 23.25% 23.16% 22.96% 27.43% 29.39%

Prospective 22.36% 22.80% 22.39% 27.36% 23.42% 23.25% 23.16% 22.96% 27.43% 29.39%

Adjusted-Potential 22.36% 22.80% 22.39% 27.36% 23.42% 23.25% 23.16% 22.96% 27.43% 29.39%

Reference Margin Level 19.50% 18.78% 19.86% 19.99% 20.00% 20.00% 20.00% 20.00% 20.00% 20.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 633 880 549 1,593 738 695 680 638 1,583 1,977 

Prospective 633 880 549 1,593 738 695 680 638 1,583 1,977 

Adjusted-Potential 633 880 549 1,593 738 695 680 638 1,583 1,977 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

 

93 Ontario IESO, for its own assessments, treats Demand Response as a resource instead of as a load-modifier. As a consequence, the Net Internal Demand, 

Planning Reserve Margins and the Target Reserve Margin numbers differ in IESO reports when compared to NERC reports. The Ontario reports would 

report lower reserve margins.

15%

18%

21%

24%

27%

30%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Nuclear Renewables Hydro Petroleum
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Demand, Resources, and Planning Reserve Margins

Ontario has invested heavily in electricity infrastructure over the past decade. Investments have enabled the phase-out of 

coal-fired generation in the province and have reduced the carbon intensity of Ontario’s electricity supply mix. Ontario’s 

electricity demand growth has been low to moderate during this period. Growing net supply additions and moderate demand 

have resulted in substantial capacity margins. Capacity margins have been reduced to more normal levels with the recent 

phase-out of coal-fired generation in the province. Ontario’s evolving supply mix features increasing and significant 

penetrations of renewable sources.

The Reference Margin Levels for the first four years of the assessment period vary between 18.78 and 20 percent through 

2020, then remain at 20 percent through 2024. This variance is necessary to reflect the changes in outages, demand forecast,

and available resources. However, the Reference Margin Levels published in this report have been modified to reflect NERC’s

reserve margin calculation. Previously, Demand Response (DR) was treated as a resource, but now it must be accounted for

in the margin calculation as a load modifier for all Assessment Areas. This approach results in a higher percent for both the 

Reference Margin Level and the projected Reserve Margins.

Between 2020 and 2024, Ontario will rely on new planned resources of up to 3,640 MW, as per Ontario’s Long-Term Energy 

Plan (LTEP), to meet the Reference Margin Level. Ontario possesses a range of options to address these needs, including 

market-based mechanisms. Additional planning activities to meet future resource adequacy needs are currently underway.

This year’s forecast of Net Energy for Load (NEL) has an average annual growth rate of -0.4 percent during the 10-year period, 

similar to the 2013LTRA forecast of -0.2 percent average growth for 2013–2023. Although there is increased demand for 

electricity driven by modest economic expansion and population growth, these increases are being more than offset by three 

key factors:

1. The growth in embedded generation and BTMG capacity, which has a significant downward impact on grid-supplied 

electricity, which is the demand value being considered (rather than total consumption).

2. Conservation impacts that reduce the overall need for both end-use and grid-supplied electricity.

3. The increasing impact of price-sensitive demand through the implementation of time-of-use rates, as well as the 

Industrial Conservation Initiative.

In general, distributed (embedded) generation (DG) is having the largest impact on grid-supplied energy demand. Summer 

peaks are particularly affected by the increased penetration of solar-powered DG. The summer peaks are also being 

influenced by efficiency changes to air conditioners.

The winter peaks are not significantly impacted by DG, because in Ontario, most is comprised of solar facilities, and the peak 

occurs after sunset, when solar DG is no longer generating power. However, the winter peak is seeing downward pressure 

from conservation savings due primarily to lighting efficiencies as end users move to compact fluorescent and LED technology.

While overall demand is expected to decline, there will be some variation within Ontario. The Greater Toronto area (GTA) 

has the largest share of the Ontario population and economy. The Essa zone, which lies just north of the GTA, will see positive 

growth resulting from ongoing expansion of the GTA. Primarily due to expected mining growth associated with vast untapped 

natural resources in the northern portions of the province, a rebound is expected during the later years of the forecast. The 

Net Internal Demand forecast in the 2014LTRA reference case is reduced by the amount of DR programs, previously counted

as resources in Ontario. For its own provincial assessments, DR programs will continue to be treated as resources.

Over the course of the forecast, the DR program impacts during the summer are expected to increase from just over 500 

MW, at present, to less than 1,500 MW by the end of the forecast period. Starting in 2020, the increased DR is expected to 

show significant growth. In the IESO, DR is comprised of three programs: Demand Response 3 (DR3), Peaksaver PLUS® 

(primarily driven by air-conditioning load), and dispatchable loads. Participation in dispatchable load programs drops during 

the peak period.
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Conservation is expected to yield incremental peak savings of more than 3,000 MW by 2024. The Ontario government’s LongTerm Energy Plan (LTEP) established a provincial conservation and demand management target of 30 TWh/year of cumulative 

savings by 2032. The reference year for the savings is 2005, with projected milestones of 11 TWh/year by 2015 and 21 

TWh/year by the end of 2024. Those savings will be achieved through improved building codes, equipment standards, and 

conservation programs.

LTEP 2013 has also set a goal to use DR to be able to meet 10 percent of net peak demand by 2025, equivalent to 

approximately 2,400 MW under forecast condition. This includes all DR programs, such as Time-of-Use rates, Industrial 

Conservation Initiative, market dispatchable load, DR3, and Peaksaver PLUS®. The responsibility for existing and newly 

introduced DR initiatives has been transferred from the Ontario Power Authority (OPA) to the IESO.

In June 2014, the IESO implemented a redesigned framework for activation of the DR3 program through integration into the 

electricity market. DR3 is a contractual peak load reduction program that encourages businesses to reduce their electricity 

use during periods of peak demand. The redesigned framework will model DR3 as aggregated resources within IESO market 

and system tools. In place of activations that are based on a combination of supply cushion and price-based triggers, DR3 

resources are activated when they represent a competitively priced energy resource in the pre-dispatch time frame (i.e.,

activated on a price trigger only).

All coal units in Ontario have been phased out as of April 2014, in accordance with Ontario government policy. In the years 

following the coal phase-out, the province’s next reliability challenge will be to carefully manage the renewal of its nuclear 

fleet. Nuclear units at Pickering Generating Station will not be refurbished, and current plans are to operate these units 

through approximately 2020.

Supply options for maintaining resource adequacy over this time period are being considered. These options include 

conservation, re-contracting Non-Utility Generator (NUG) facilities as their contracts reach maturity, new gas-fired 

generation, and conversion of some or all of the Lambton and Nanticoke coal-fired units to natural gas, imports, and energy 

storage. About 1,400 MW of NUG contracts have the opportunity to be renegotiated as the contracts are expiring within the 

next decade. The OPA is in the process of renegotiating the NUG contracts. 

Over the assessment period, the capacity of embedded generation, such as DERs and BTMG, is expected to increase 

significantly. The Feed-in Tariff (FIT) and microFIT programs drive this growth with renewable generation. Over the forecast 

period, about 2,500 MW of wind and solar DG is projected to be added—most of which is solar. By 2024 there will be over 

4,000 MW of DG in Ontario.

In 2014, the IESO issued a request for proposals to procure up to 35 MW of energy storage to explore how new technologies 

can provide additional flexibility to carry out grid operations. The IESO storage procurement process supports the LTEP, which

calls for 50 MW of energy storage in Ontario. Subsequent to the IESO’s procurement process, the OPA will issue a request for 

proposals for the remaining 15 MW. These procurements are structured to maximize learning about energy storage services 

and how they can best serve Ontario’s needs. Contracts were planned to be executed during the summer of 2014 and become

operational sometime in 2017.

About 14 percent of the installed wind capacity is assumed to be available at the time of summer peak, and 33 percent is 

assumed to be available at the time of winter peak. Ontario’s solar capacity value is forecast to be 30 percent of installed 

capacity for the summer peak and 4 percent for the winter peak. The assumed capacity contribution for hydroelectric is 71 

percent for the summer peak and 76 percent for the winter peak.

To meet the challenge of rapid deployment of renewables across the province and help capture the benefits of Ontario’s 

investment in variable generation, the IESO has adapted power system planning and operations, as well as the IESOadministered markets to accommodate the influx of renewables. The IESO implemented the Renewables Integration Initiative 

(RII) in 2013 to effectively integrate up to 10,700 MW of renewable generation by 2021. RII has already yielded results, 
NPCC-Ontario

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66

including the integration of the hourly centralized forecast into IESO scheduling tools, and enhanced visibility of renewable 

output of distributed-connected variable generation facilities 5 MW or greater. This was accomplished by providing System 

Operators with greater levels of awareness of system conditions. Improved variable generation forecasting and greater 

visibility is expected to bring measurable benefits to the maintenance of system reliability and market efficiency. The dispatch 

of grid-connected renewable resources provides increased flexibility from available variable generation resources and will 

allow IESO to operate the system reliably by providing the needed tools to manage issues such as ramp needs and surplus 

baseload generation (SBG) situations. 

Frequency response, short-term inertial response, voltage ride-through capability, and voltage support are some of the 

performance requirements clearly identified during the connection process and validated through tests before the new gridconnected resources complete their facility registration with the IESO. Frequency response and voltage ride-through 

capability requirements also apply to distribution-connected resources larger than 10 MW. To capture the effects of all DG

on the performance of the grid, including those smaller than 10 MW, the IESO periodically conducts system studies. If needed, 

mitigating measures such as grid-connected SVCs will be developed and requested to be implemented.

Capacity transfers are not considered in this assessment, as Ontario does not have any Firm contracts with other areas.

Emergency imports are not considered in this assessment. However, for use during daily operation, operating agreements 

between IESO and neighboring jurisdictions in NPCC, RF, and MRO include contractual provisions for emergency imports into

IESO. IESO also participates in a shared activation of reserve groups, including IESO, ISO-NE, Maritimes, NYISO, and PJM.

Transmission Outlook and System Enhancements

Northwestern Ontario is connected to the rest of the province by the double-circuit, 230 kV East–West Tie. The primary 

source of generation within the northwest is hydroelectric. In addition, strong local load growth is forecast, as mentioned 

above. Additional capacity is required to maintain reliable supply to this area under the wide range of possible system and 

water conditions. The expansion of the East–West Tie with the addition of a new double-circuit 230 kV transmission line is 

expected to be in service by 2018 and will provide reliable and cost-effective long-term supply to the northwest.

Long-Term Reliability Issues

The renewable resources target for wind, solar, and biomass is 10,700 MW by 2021, which is accommodated through 

transmission expansion and maximized use of the existing system. Ontario will add a few hundred MW of hydroelectric 

capacity to reach a target of 9,300 MW by 2025. A substantial amount of renewable generation is embedded and included in 

the demand forecast. This level of variable generation will be incorporated into the system through the development of new 

facilities and significant investments to upgrade existing facilities in Ontario. The operational and adequacy concerns of 

integrating of new variable generation are addressed through RII and the connection requirements imposed by the IESO on 

grid-connected resources, and on resources larger than 10 MW connecting to the distribution system.

A reduction of SBG events is expected after the nuclear refurbishment programs begin. The vast majority of SBG is currently 

managed through normal market mechanisms, including export scheduling and nuclear maneuvering. The IESO’s variable 

generation dispatch tools have provided additional flexibility to alleviate most SBG events.

In light of environmental and other concerns, coal-fired generation has been replaced in Ontario by sources that emit less 

carbon. In the years ahead, natural gas-fired generation will play an important role in Ontario’s supply mix balance, providing 

the flexibility to cushion the electricity system when demand and intermittent resources rise or fall.

Almost all of Ontario’s oil and natural gas comes from outside the province. In addition to the use of these fuels for electricity 

generation, Ontario relies on oil and natural gas to support basic needs such as heat and transportation. In particular, reliance 

on natural-gas-fired generation will grow as this form of generation represents an essential element in the sustainability of a 

responsive and flexible electricity system. Supply to Ontario’s gas fleet is supported by significant Firm supply and 

transportation contracts. The IESO is an active participant in the Eastern Interconnection Planning Collaborative effort in the 
NPCC-Ontario

NERC | 2014 Long-Term Reliability Assessment | November 2014

67

ongoing development of the Gas-Electric System Interface Study,

94 which evaluates the capability of natural gas systems to 

satisfy the future needs of the electric system across most of the Eastern Interconnection.

With the growth in conservation savings and DG, demand forecasting has become more complex. Smart meters and higher 

on-peak electricity prices has introduced consumer price response previously not seen in Ontario. Traditionally, demand was 

a function of weather conditions, economic cycles, and population growth. With multiple factors influencing demand, 

determining the causality of demand changes has become increasingly nuanced and requires greater data and analysis.

 

94 EIPC: Gas-Electric System Interface Study.
NERC | 2014 Long-Term Reliability Assessment | November 2014

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NPCC-Québec

Assessment Area Overview

The Québec Assessment Area (Province of Québec) is a winter-peaking NPCC subregion that covers 595,391 square miles with a population 

of eight million. Québec is one of the four NERC Interconnections in North America, with ties to Ontario, New York, New England, and the 

Maritimes, consisting either of HVdc ties or radial generation or load to and from neighboring systems.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

Reference Margin Levels are drawn from the Québec Area 2013 

Interim Review of Resource Adequacy, which was approved by 

NPCC’s Reliability Coordinating Committee in December 2013.

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Winter

Planning Considerations for Wind Resources

On-peak contribution is approximately 30 percent of the total

Planning Considerations for Solar Resources

N/A

Footprint Changes

N/A

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 38,316 38,612 38,847 39,168 39,567 40,218 40,558 40,862 41,120 41,373

Demand Response 1,708 1,852 1,902 1,952 2,002 2,202 2,252 2,252 2,252 2,252

Net Internal Demand 36,608 36,760 36,945 37,216 37,565 38,016 38,306 38,610 38,868 39,121

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 41,257 41,628 42,421 43,602 43,637 44,028 44,051 44,086 44,121 44,121

Prospective 41,257 41,628 42,421 43,602 43,637 44,028 44,051 44,086 44,121 44,121

Adjusted-Potential 41,257 41,628 42,421 43,602 43,637 44,028 44,051 44,086 44,121 44,121

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 12.70% 13.24% 14.82% 17.16% 16.16% 15.81% 15.00% 14.18% 13.51% 12.78%

Prospective 12.70% 13.24% 14.82% 17.16% 16.16% 15.81% 15.00% 14.18% 13.51% 12.78%

Adjusted-Potential 12.70% 13.24% 14.82% 17.16% 16.16% 15.81% 15.00% 14.18% 13.51% 12.78%

Reference Margin Level 11.60% 12.10% 12.10% 12.10% 12.10% 12.10% 12.10% 12.10% 12.10% 12.10%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 476 384 968 1,845 1,489 1,374 1,071 765 511 226 

Prospective 476 384 968 1,845 1,489 1,374 1,071 765 511 226 

Adjusted-Potential 476 384 968 1,845 1,489 1,374 1,071 765 511 226 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

10%

11%

12%

13%

14%

15%

16%

17%

18%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

0.0

0.5

1.0

1.5

2.0

2.5

3.0

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Hydro Natural Gas Renewables
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Demand, Resources, and Planning Reserve Margins

The Reference Margin Levels are drawn from the Québec Area 2013 Interim Review of Resource Adequacy95 and vary between 

10 and 12 percent. The Anticipated Reserve Margin varies between 12.8 and 17.2 percent, remaining above the Reference 

Margin Level for all seasons and years during the assessment period.

The Québec Area demand forecast has increased compared to the 2013LTRA report, mainly due to industrial sector growth. 

The demand forecast average annual growth is 0.9 percent during the 10-year period, similar to the 1.0 percent forecast in 

the 2013LTRA.

Energy efficiency and conservation programs are integrated in the demand forecasts and account for 1,550 MW for the 2015–

2016 winter peak. These programs are implemented throughout the year by Hydro-Québec Distribution (HQD) and by the 

provincial government, through its Ministry of Natural Resources. Energy efficiency will continue to grow during the entire 

assessment period.

Demand forecasts also take into account the load shaving that results from the residential dual-energy space-heating 

program. The impact of this program on peak load demand is estimated to be around 650 MW during the assessment period

Demand Response (DR) programs in the Québec Area are specifically designed for peak load reduction during winter 

operating periods and are mostly interruptible demand programs (for large industrial customers), totaling 1,458 MW for the 

2015–2016 winter period. DR is usually used in situations when load is expected to reach high levels, or when resources are 

not expected to be sufficient to meet load during peak periods. DR remains relatively stable during the assessment period, 

with a maximum of 2,252 MW reached during 2021–2022 winter season. 

The Québec Area is currently developing new DR programs, including Direct Control Load Management (DCLM), which could 

provide an additional 300 MW of DR by 2021–2022. Total on-peak DSM (including energy efficiency and conservation 

programs) for the 2024–2025 winter period is projected to be approximately 5,250 MW.

A total of 1,560 MW of new hydro generation is expected to be in service by 2021. Additional updates to existing hydro 

generation will add an additional 400 MW of capacity during the assessment period. With regard to other renewable

resources (biomass and wind), a total of 1,900 MW is expected to be in service by 2021. At this time, all projects are expected 

to be on time and there are no cancellations or deferments.

Biomass and wind resources are owned by Independent Power Producers (IPPs). These IPPs have signed contractual 

agreements with Hydro-Québec. Therefore, for biomass resources, maximum capacity and expected on-peak capacity are 

equal to contractual capacity, representing almost 100 percent of nameplate capacity. For wind resources, capacity 

contribution at peak is estimated at 30 percent of contractual capacity, representing 970 MW and 1,220 MW, respectively,

for the 2015–2016 and 2024–2025 winter periods. Maximum wind capacity is set equal to contractual capacity, which 

generally equals nameplate capacity. For summer peak period calculations, the expected on-peak wind capacity is set to zero 

as wind resources are derated by 100 percent. BTMG is negligible and is embedded in the load forecast.

Expected transfer (capacity) purchases are planned by Hydro-Québec Distribution as needed to meet the Québec internal 

demand. These purchases are set at 1,100 MW throughout the assessment period and may be supplied by resources located 

in Québec or in neighboring markets. In this regard, Hydro-Québec Distribution has designated the Massena–Châteauguay 

(1,000 MW) and Dennison–Langlois (100 MW) interconnections’ transfer capacity to meet its resource requirements during 

winter peak periods. These purchases are not backed by Firm long-term contracts. However, on a yearly basis, Hydro-Québec 

Distribution proceeds with short-term capacity purchases of Unforced Capacity (UCAP) as needed in order to meet its capacity 

requirements for the upcoming winter. The Québec Area does not rely on any emergency capacity imports to meet its 

Reference Margin Level. The Québec Area will support Firm capacity sales totaling 974 MW to New England and Ontario 

 

95 Québec Area 2013 Interim Review of Resource Adequacy, approved by NPCC’s Reliability Coordinating Committee on December 3, 2013.
NPCC-Québec

NERC | 2014 Long-Term Reliability Assessment | November 2014

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(Cornwall) during the 2015–2016 winter peak period. This capacity is backed by Firm contracts for both generation and 

transmission and declines to 145 MW in 2020.

Transmission Outlook and System Enhancements

TransÉnergie’s system consists of an extensive 735 kV network underlain with 315 kV, 230 kV, 120 kV, and 69 kV subsystems 

totaling 20,886 line miles (33,613 km). The system uses telecommunications and advanced protection and control 

applications to ensure its reliability and improve its performance. This will continue into the future. The system is planned

according to NPCC and NERC Planning Standards, but with additional criteria that (1) consider system topology and substation 

characteristics particular to TransÉnergie’s system (complementary contingencies) and (2) address voltage sensitivity to load 

variation and interconnection ramping.

Romaine River Hydro Complex Integration

Construction of the first phase of transmission for the Romaine River Hydro Complex project is presently underway. The total 

capacity will be 1,550 MW. The generating stations will be integrated on a 735 kV infrastructure initially operated at 315 kV. 

Romaine-2 (640 MW) and Romaine-1 (270 MW) will be integrated between 2014 and 2016 at Arnaud 735/315/161 kV 

substation. One 315/161 kV, 500 MVA transformer is required at Arnaud for this project. Romaine-3 (395 MW) and Romaine4 (245 MW) will be integrated between 2017 and 2020 at Montagnais 735/315 kV substation.

The main system upgrades for this project require construction in 2014 of a new 735 kV switching station to be named Aux 

Outardes. It will be located between the existing Micoua and Manicouagan transformer substations. Two 735 kV lines will be 

redirected into the new station, and one new 3 mile (5 km) 735 kV line will be built between Aux Outardes and Micoua.

Bout-de-l’Île 735 kV Section

In 2013, TransÉnergie added a new 735 kV section at Bout-de-l’Île substation located at the east end of Montréal Island. The 

Boucherville – Duvernay line (Line 7009) has been looped into this substation, and the first of two ±300 MVar Static Var 

Compensators (SVC) has been added to the 735 kV section.

The second SVC will be added in 2014, as well as two 735/315 kV 1,650-MVA transformers banks. This new 735 kV source will 

allow redistribution of load around the Greater Montréal area and will accommodate load growth in the eastern part of 

Montréal. This project will enable future major modifications to the Montréal area regional sub-system. Many of the present 

120 kV distribution substations will be rebuilt into 315 kV substations, and the Montréal regional network will be converted 

to 315 kV.

Chamouchouane – Montréal 735 kV Line

Planning studies have shown the need to reinforce the transmission system with a new 735 kV line in the near future. The 

line will extend from the Chamouchouane substation on the eastern James Bay subsystem to a substation in Montréal (255 

miles (410 km)). It will reduce transfers on other parallel lines on the 735 kV Southern Interface, thus optimizing operation 

flexibility and reducing losses.

Planning, permitting, and construction delays are such that the line is scheduled with an on-line date of 2018–2019 winter 

peak period. Public information meetings have begun on this project. The final line route has not completely been determined 

yet, and authorization processes are ongoing.

The Northern Pass Transmission Project

This project to increase transfer capability between Québec and New England by 1,200 MW is currently under study. It 

involves construction of a ±300 kV dc transmission line about 75 km (47 miles) long from Des Cantons 735/230 kV substation 

to the Canada–United States border. This line will be extended into the United States to a substation to be built in Franklin, 

New Hampshire.

The project in Québec also includes the construction of two 600 MW converters at Des Cantons and a 300 kV dc switchyard. 

The planned in-service date has been re-evaluated to winter 2018–2019.
NPCC-Québec

NERC | 2014 Long-Term Reliability Assessment | November 2014

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The Champlain-Hudson Power Express Project

This project to increase transfer capability between Québec and New York by 1,000 MW is currently under study.

96 The project 

involvesthe construction of a ±320 kV dc underground transmission line about 50 km (31 miles) long from the Hertel 735/315

kV substation just south of Montréal to the Canada–United States border. This line will be extended underground and 

underwater (Lake Champlain and Hudson River) to Astoria station in New York City. The project in Québec also includes the 

construction of one 1,000 MW converter at Hertel. The planned in-service date is fall 2017. 

Other regional substation and line projects are in the planning or permitting stages. There are about a dozen regional 

transmission projects in the Montréal and Québec City areas and another dozen in other areas with in-service dates from 

2014 to 2020, consisting mostly of 315/25 kV and 230/25 kV distribution substations to replace 120 kV and 69 kV

infrastructures.

Long-Term Reliability Issues

Given the importance of hydroelectric resources within the Québec Area, an energy criterion has been developed to assess 

energy reliability. The criterion states that sufficient resources should be available to go through sequences of two or four

consecutive years of low water inflows totaling 64 TWh and 98 TWh, respectively, with a 2 percent probability of occurrence. 

These assessments are presented three times a year to the Régie de l'énergie du Québec (Québec Energy Board). Normal 

hydro conditions are projected during the assessment period, and reservoir levels are expected to be sufficient to meet both 

peak demands and daily energy demand. 

However, while technical developments in recent years have contributed to creating a more reliable system, sustainable 

system reliability may be challenged by several issues. For example, wind generation integration has not significantly 

impacted day-to-day operation of the system, and the actual level of wind generation does not require particular operating 

procedures. However, with the increasing amount of wind on the system, there is a potential for impacts on system 

management. Accordingly, the following issues are currently under study: 

 Wind generation variability on system load and interconnection ramping

 Frequency and voltage regulation

 Increase of start-ups/shutdowns of hydroelectric units due to load following coupled with wind variability

 Efficiency losses in generating units and/or reduction of low-load operation flexibility due to the low inertia 

response of wind generation coupled with must-run hydroelectric generation

In addition to these issues, there are occasions during recent summers when several 735 kV lines in the southern part of the 

system became heavily loaded due to the hot temperatures in southern Québec. Although this is a new issue for the Québec 

Area, it is expected to occur again with increased air conditioning loads and growing exports to other summer-peaking 

systems. More recently, studies have been performed and thermal limits have been optimized with other mitigating measures

to address the potential for future line overloads following a contingency during periods of hot temperatures.

 

96 Federal Register Notice – October 1, 2014.
NERC | 2014 Long-Term Reliability Assessment | November 2014

72

PJM

Assessment Area Overview

PJM Interconnection is a regional transmission organization (RTO) that coordinates the movement of wholesale electricity in all or parts of 

Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West 

Virginia, and the District of Columbia. PJM companies serve 61 million people and cover 243,417 square miles. PJM is a Balancing Authority, 

Planning Coordinator, Transmission Planner, Resource Planner, Interchange Authority, Transmission Operator, Transmission Service 

Provider, and Reliability Coordinator.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

The PJM RTO Reserve Requirement is applied as the Reference 

Margin Level for this assessment.

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Summer

Planning Considerations for Wind Resources

On-peak contribution of 13 percent of installed capacity

Planning Considerations for Solar Resources

38 percent of nameplate capacity

Footprint Changes

The East Kentucky Power Cooperative (EKPC), which integrated 

into the PJM RTO on June 1, 2013, is now part of PJM’s load and 

generation data.

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 160,259 162,470 164,195 165,479 166,900 168,593 170,027 171,217 172,542 173,729

Demand Response 14,812 12,402 12,402 12,402 12,402 12,402 12,402 12,402 12,402 12,402

Net Internal Demand 145,447 150,068 151,793 153,077 154,498 156,191 157,625 158,815 160,140 161,327

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 183,163 192,850 190,497 185,904 185,928 185,928 185,928 185,928 185,928 187,498

Prospective 186,787 197,909 195,818 195,962 194,767 194,768 194,768 194,768 194,768 196,338

Adjusted-Potential 186,787 197,909 195,818 195,962 194,767 194,768 194,768 194,768 194,768 196,338

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 25.93% 28.51% 25.50% 21.44% 20.34% 19.04% 17.96% 17.07% 16.10% 16.22%

Prospective 28.42% 31.88% 29.00% 28.02% 26.06% 24.70% 23.56% 22.64% 21.62% 21.70%

Adjusted-Potential 28.42% 31.88% 29.00% 28.02% 26.06% 24.70% 23.56% 22.64% 21.62% 21.70%

Reference Margin Level 15.70% 15.70% 15.70% 15.70% 15.70% 15.70% 15.70% 15.70% 15.70% 15.70%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 14,880 19,221 14,873 8,793 7,173 5,215 3,555 2,179 646 842 

Prospective 18,504 24,280 20,193 18,852 16,013 14,055 12,395 11,019 9,486 9,682 

Adjusted-Potential 18,504 24,280 20,193 18,852 16,013 14,055 12,395 11,019 9,486 9,682 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

10%

15%

20%

25%

30%

35%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-4

-2

0

2

4

6

8

10

12

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Nuclear Renewables

Hydro Coal Petroleum
PJM

NERC | 2014 Long-Term Reliability Assessment | November 2014

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Demand, Resources, and Planning Reserve Margins

The PJM RTO Reserve Requirement as calculated by PJM is 15.7 percent for the 2015–2016 planning period, which runs from 

June 1, 2015, through May 31, 2016. The PJM RTO Reserve Requirement is 0.5 percentage points lower this year compared 

to the 2014–2015 value due to the retirement of coal units with high forced outage rates. The 15.7 percent PJM RTO Reserve 

Requirement (applied as the Reference Margin Level) is applicable for the entire assessment period. PJM RTO will have an 

adequate Anticipated Reserve Margin though the entire assessment period. The Prospective and Adjusted-Potential Reserve 

Margins are also above the Reference Margin Level for the entire assessment period.

Use of more granular historical economic data and the addition of another year of load experience to the load forecasting 

model resulted in generally lower (approximately 0.5 percent) peak and energy forecasts this year compared to the forecast 

done last year. Annualized 10-year growth rates for individual zones range from 0.4 percent (Rockland Electric) to 1.8 percent 

(Dominion Virginia Power).

PJM has filed tariff changes with FERC that will require more robust reporting of the DR operational capability in real time for 

Curtailment Service Providers. PJM does not have reliability concerns with DR expansion, but the additional operational 

information will help avoid the dispatch of DR that may not be necessary to meet the need of the emergency conditions. PJM 

has created three different DR products to address the issue of availability: Limited DR (10 days for 6 hours per day during 

the summer peak period), Extended Summer DR (unlimited days during the summer peak period for 10 hours per day) and 

Annual DR (unlimited days for 10 hours per day any time of the year). These programs require necessary amounts of annual 

capacity to fulfill the PJM reliability requirements.

The PJM reported transactions are the aggregate of generator-specific transactions. These transactions include the Firm

reservation rights for the generation and Firm transmission rights to transfer the power across the PJM border. Long-term 

Firm capacity transfer contacts exist, but they are not accepted into PJM installed capacity until the PJM Reliability Planning 

Model (RPM) three-year planning window. The impact of transactions is minimal in PJM since they only amount to about two 

percent of the forecast peak load. PJM previously forecast transactions using the Firm capacity contracts but has recently 

decided to only show capacity transactions through a three-year planning window to coordinate with neighboring entities.

Energy efficiency programs included in the 2015–2017 load forecast are approved for use in the RPM and total 685 MW for 

the 2015 summer. This value increases to 918 MW in 2016 and remains constant through the end of the assessment period.

Transmission Outlook and System Enhancements

Northeast New Jersey Transmission Enhancement

PJM 2013 RTEP process results have validated the need for a solution to identified short circuit duty violations at the Essex, 

Kearney, and New Jersey Transit Meadowlands (NJT Meadows) 230 kV substations. Notably, 2013 short circuit analyses 

revealed that the two 345 kV tie lines connecting PSE&G’s Hudson substation to ConEd’s Farragut substation contribute to 

short circuit duties at Hudson, Kearney, and Essex. As a result, the Hudson/Farragut HVdc alternative was originally 

recommended in large part for its ability to block this fault current pass-through to the northern New Jersey PSE&G system. 

However, circuit breaker short circuit over duties were not the only NERC criteria violations identified. Generator 

deliverability tests identified thermal violations on lines in northern New Jersey that have required reconsideration of PJM’s 

initial HVDC solution proposal and the subsequent development of a more comprehensive solution.

In collaboration with PSE&G planning staff, PJM evaluated two northern New Jersey double-circuit upgrade solutions: one at 

230 kV and one at 345 kV. Additionally, the double-circuit 345 kV solution also solves the identified thermal criteria violations 

in northern New Jersey.

In parallel with the analytical work performed to compare the double-circuit 345 kV and HVDC alternatives, PJM also retained 

an independent engineering consultant to review each project, validate cost estimates, and assess the project 

constructability. From that perspective, the consultant’s findings did not identify any “fatal flaws” that would prevent either 

project from being implemented. Based on the performance of each of the alternatives, the cost of each, and the findings of 
PJM

NERC | 2014 Long-Term Reliability Assessment | November 2014

74

the independent consultant regarding constructability, PJM recommended the double-circuit 345 kV alternative to address 

the short circuit and thermal problems in northern New Jersey. The PJM Board approved the recommendation in December 

2013.97

Need for Byron – Wayne Confirmed

PJM reviewed—as it does every year—transmission plans developed in earlier years. By doing so, PJM can determine 

whether, as a result of changing assumptions, previously approved transmission upgrades are still required. And, if so, PJM 

can determine whether they are still required in the year originally identified, as with the Byron – Wayne 345 kV transmission 

line (Grand Prairie Gateway). As part of its 2012 RTEP process, PJM conducted its annual simultaneous feasibility analysis to 

assess the transmission system’s ability to accommodate all transmission rights for the next 10-year period. PJM’s 2012 

transmission rights analysis identified 16 thermal constraints in ComEd and nine PJM-MISO market-to-market constraints. 

RTEP analysis in 2013 also identified a number of thermal constraints similar to those identified in 2012, confirming the need 

for the Byron – Wayne 345 kV in 2017.

Artificial Island Order 1000 Proposal Window

PJM sought proposals from April 29, 2013, through June 28, 2013, to improve operational performance on Bulk Electric 

System (BES) facilities in the southern New Jersey Artificial Island area, the site of PSE&G’s Salem 1 and 2 and Hope Creek 1 

nuclear generating plants. Under certain system conditions, this area’s complexity has presented PJM and PSE&G System 

Operators with limited solutions, potentially forcing them in some circumstances to remove an Artificial Island unit from 

service in order to stay within operating limitations to maintain reliability. PJM specified that RTEP proposals improve limited 

stability margins, minimum Artificial Island MVar output requirements, and previously identified high-voltage reliability 

issues.

Seven different sponsors submitted 26 separate proposals. Proposals reflected a diverse range of technologies at both 500 

kV and 230 kV—new transformation, substations and associated equipment, additional circuit breakers, system 

reconfiguration, dynamic reactive devices, dynamic series compensation and DC technology—spanning a range of project risk 

exposure levels and lead-time requirements. In parallel with analytical evaluation, PJM enlisted engineering consultants in 

2013 to evaluate project proposal constructability in terms of physical characteristics, feasibility, cost, design commonalities,

and other challenges associated with line and river crossings. Additionally, the consultants examined the ability to expand or 

reconfigure existing substations and determine required transmission and generation outages.

Market Efficiency Order 1000 Proposal Window

During this window, PJM sought proposals to identify transmission projects to relieve internal PJM transmission congestion. 

The scope of the request encompassed the top 25 congestion events observed in 2013 Market Efficiency Analysis for study 

years 2017, 2020, and 2023 and for which no reliability-based RTEP upgrades have been already identified. Proposed 

enhancements must provide a benefit/cost ratio of at least 1.25 and must not introduce any reliability criteria violations. Six 

different sponsors submitted 17 separate proposals during the window to meet the stated requirements. Analysis identified 

three proposals for further evaluation. All three addressed, either in whole or part, congestion on the Hunterstown 230/115 

kV transformer. PJM expects to make a recommendation to the Board in 2014 that comprises adding a second Hunterstown 

230/115 kV transformer and reconductoring the existing Hunterstown–Oxford 115 kV line.

AEP/Dominion Transmission Rebuilds

PJM’s RTEP includes 500 kV transmission line rebuild projects over the next eight years by AEP and Dominion asshown below.

The towers of all six lines, built in the 1960s, are nearing the end of their useful lives and will soon require rebuild. Now the 

Cloverdale – Lexington and Lexington – Dooms 500 kV line rebuilds have been identified to solve PJM baseline reliability 

criteria violations.

 

97 2013 Regional Transmission Expansion Plan Report (see page 7).
PJM

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AEP/Dominion Line Rebuilds

Line Rebuild Driver In-Service Month, Year

Cloverdale – Lexington 500 kV NERC Category C3 “N-1-1” Criteria December 2016

Lexington – Dooms 500 kV Dominion Reliability Criteria Violation June 2016

Dooms – Cunningham 500 kV Dominion Supplemental Project December 2018

Cunningham – Elmont 500 kV Dominion Supplemental Project May 2018

Mt. Storm – Valley 500 kV Dominion Supplemental Project June 2021

Valley – Dooms 500 kV Dominion Supplemental Project December 2021

Cloverdale – Lexington 500 kV Line

RTEP analysis conducted in 2013 identified reliability criteria violations under PJM light-load criteria tests on the AEP portion 

of the Cloverdale – Lexington 500 kV line. In October 2013, the Board approved PJM’s upgrade recommendation to rebuild 

the AEP portion of the Cloverdale – Lexington 500 kV line, including replacement of 11 tower structures. This follows 

December 2011 PJM Board approval to reconductor the Dominion portion of the Cloverdale – Lexington 500 kV circuit to 

solve NERC criteria Category C violations. Jointly owned by Dominion and AEP, coordinated plans are underway to rebuild 

and/or reconductor their respective portions of the 44 mile line in order to increase the operational limit of that line to meet 

PJM’s minimum summer emergency requirement of 3,992 MVA.
PJM

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Dooms – Lexington 500 kV Line

PJM 2012 RTEP analysis identified a Dominion reliability criteria violation in 2016 in which the Dooms – Lexington line would 

be overloaded for several N-1-1 contingencies. In May 2012, the PJM Board approved the recommended solution to 

reconductor the line, increasing its rating from 2,913 MVA to 4,340 MVA. The project is expected to be completed by 

December 2016.

State RPS laws require entities that serve load to do so using various eligible renewable resources including wind, solar, and 

other technologies. States in the PJM footprint have a variety of RPS definitions and targets. Overall, approximately 38 GW 

of renewable energy would be required from renewable resources to meet aggregate RPS targets by 2028 in states in which 

PJM operates. And, while NERC Reliability Standard violations remain PJM’s principal basis under the RTEP Protocol for 

justifying transmission expansion, construction of major transmission infrastructure will likely be necessary to support the 

achievement of RPS public policy goals.

Wind- and solar-powered facilities—now an expanding percentage of interconnection requests—constitute a growing driver 

of regional transmission expansion. The emergence of state RPS standards has prompted PJM to further examine the impacts 

of extensive penetration of wind resources, which could have implications on reliability and market efficiency. During 2013, 

both internal scenario studies and interregional studies examined the penetration of renewable-powered generation to meet 

state RPS targets. Those studies confirm that significant build-out of transmission will be needed for PJM to deliver the 

aggregate wind generation required to meet states’ RPS goals.

BTMG is not counted as PJM capacity and has no effect on the PJM Reserve Margin. During a hot-weather event in September 

2013,98 PJM called on some BTMG to operate to alleviate specific transmission-related operating concerns. PJM will establish 

and document an approach for representing known BTMG in PJM’s energy management systems and the related operating 

criteria for dispatchers. Working with the states and the Transmission Owners, PJM will better incorporate BTMG into 

emergency operations.

Long-Term Reliability Issues

Light-load system conditions, as low as 30 percent of summer peak for some transmission owners, present system dispatchers 

with operational performance issues. Generation dispatch under such conditions differs markedly from that under peak-load 

conditions, particularly for units powered by renewable sources such as wind. PJM has begun to experience thermal overloads 

and high-voltage events driven by low demand dispatch patterns and the capacitive effects of lightly loaded transmission 

lines. From a 15-year planning perspective, these light-load concerns gave rise to the approval of new reliability criteria 

analysis procedures in 2010, first implemented and benchmarked in 2011, for both baseline analysis and queued 

interconnection request studies. Light-load reliability analysis ensures that the system transmission is capable of delivering 

generating capacity under such conditions.

As part of its 2013 cycle of RTEP studies, PJM identified six light-load criteria violations, five of which represented normal and 

N-1 thermal overloads. The most significant of these is a project to rebuild the AEP portion of the Cloverdale – Lexington 500 

kV line in Virginia that will require $40 million, expected by June 2015. The remaining four thermal criteria violations will 

require 138 kV upgrades in AEP and ComEd; they are much lower in scope and estimated cost and are expected by June of 

2017. The sixth criteria violation, voltage in nature, requires an upgrade to the 765 kV Cloverdale substation, also in Virginia, 

and construction of a new 500 kV bus with an estimated project cost of $85 million projected to be in service by the end of 

2016.

PJM planning staff has initiated efforts with operations staff and individual TOs to examine real-time high-voltage events 

across the RTO. Based on additive power flow studies completed in 2013, PJM collaborated with TOs to develop solutions 

approved by the PJM Board that ultimately included shunt reactors, SVCs, reactor breakers, and modifications to, and 

 

98 PJM Report: Technical Analysis of Operational Events and Market Impacts. 
PJM

NERC | 2014 Long-Term Reliability Assessment | November 2014

77

optimization of existing facilities, generator voltage schedule adjustments, transformer tap settings, and switched shunt 

capacitor settings.

Planning study results that were reviewed with TOs to determine optimal reactor sizes and locations across PJM to maximize 

their effectiveness at mitigating high voltages were subsequently confirmed by additional power flow analysis. In-service 

dates for these projects begin in June 2015.
NERC | 2014 Long-Term Reliability Assessment | November 2014

78

SERC

Assessment Area Overview

SERC is a summer-peaking Assessment Area that covers approximately 308,900 square miles and serves a population estimated at 39.4 

million. SERC is divided into three Assessment Areas: SERC-E, SERC-N, and SERC-SE. The SERC Region includes 11 BAs: Alcoa Power 

Generating, Inc. – Yadkin Division (Yadkin), Associated Electric Cooperative, Inc. (AECI), Duke Energy Carolinas and Duke Energy Progress 

(Duke), Electric Energy, Inc. (EEI), LG&E and KU Services Company (as agent for Louisville Gas and Electric (LG&E) and Kentucky Utilities 

(KU)), PowerSouth Energy Cooperative (PowerSouth), South Carolina Electric & Gas Company (SCE&G), South Carolina Public Service 

Authority (Santee Cooper, SCPSA), Southern Company Services, Inc. (Southern), and Tennessee Valley Authority (TVA).

Summary of Methods and Assumptions Assessment Area Footprints (SERC-E, SERC-N, SERC-SE)

Reference Margin Level

Entities within the SERC footprint adhere to state-set targets that 

vary throughout the footprint. For this assessment, NERC applies a 

15 percent Reference Margin Level for all SERC subregions.

Load Forecast Method

Noncoincident; normal weather (50/50)

Peak Season

Summer

Planning Considerations for Wind Resources

As reported by individual generator owners

Planning Considerations for Solar Resources

As reported by individual generator owners

Footprint Changes

East Kentucky Power Cooperative (EKPC) joined PJM on June 1, 

2013, and is no longer reported in SERC’s Assessment Area. 

Additionally, entities within the SERC-W Assessment Area joined 

MISO in December 2013.

SERC-East: Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 44,086 44,768 45,398 45,992 46,669 47,289 47,928 48,579 49,251 49,943

Demand Response 1,757 1,819 1,869 1,913 1,934 1,952 1,970 1,986 2,003 2,006

Net Internal Demand 42,329 42,949 43,529 44,079 44,735 45,337 45,958 46,593 47,248 47,937

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 50,475 50,396 50,339 51,440 52,363 52,226 52,243 52,666 52,682 52,702

Prospective 53,773 53,694 53,637 54,738 55,661 55,524 55,541 55,964 55,980 56,000

Adjusted-Potential 53,773 53,694 53,712 54,826 55,918 55,781 55,882 56,429 56,445 56,577

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 19.24% 17.34% 15.64% 16.70% 17.05% 15.19% 13.68% 13.03% 11.50% 9.94%

Prospective 27.04% 25.02% 23.22% 24.18% 24.42% 22.47% 20.85% 20.11% 18.48% 16.82%

Adjusted-Potential 27.04% 25.02% 23.39% 24.38% 25.00% 23.04% 21.59% 21.11% 19.47% 18.02%

Reference Margin Level 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 1,796 1,004 280 749 918 88 (609) (916) (1,653) (2,426)

Prospective 5,095 4,303 3,579 4,047 4,216 3,387 2,689 2,382 1,645 873 

Adjusted-Potential 5,095 4,303 3,654 4,135 4,472 3,643 3,030 2,847 2,110 1,450 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

0%

5%

10%

15%

20%

25%

30%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-1.0

0.0

1.0

2.0

3.0

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Nuclear Coal
SERC

NERC | 2014 Long-Term Reliability Assessment | November 2014

79

SERC-North: Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 42,100 42,571 42,917 43,298 43,677 44,018 44,470 44,908 45,359 45,797

Demand Response 2,117 2,224 2,314 2,437 2,555 2,670 2,786 2,908 3,022 3,105

Net Internal Demand 39,983 40,347 40,603 40,861 41,122 41,348 41,684 42,000 42,337 42,692

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 50,585 49,326 49,342 49,212 49,471 49,471 49,471 49,471 48,547 48,547

Prospective 52,478 52,926 52,942 52,812 53,071 53,071 53,071 53,071 53,078 53,078

Adjusted-Potential 52,478 52,926 52,942 52,878 53,137 53,137 53,137 53,137 53,222 53,222

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 26.52% 22.25% 21.52% 20.44% 20.30% 19.65% 18.68% 17.79% 14.67% 13.71%

Prospective 31.25% 31.18% 30.39% 29.25% 29.06% 28.35% 27.32% 26.36% 25.37% 24.33%

Adjusted-Potential 31.25% 31.18% 30.39% 29.41% 29.22% 28.51% 27.48% 26.52% 25.71% 24.67%

Reference Margin Level 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 4,604 2,927 2,648 2,222 2,181 1,921 1,534 1,171 (141) (549)

Prospective 6,498 6,527 6,249 5,822 5,781 5,521 5,135 4,771 4,391 3,983 

Adjusted-Potential 6,498 6,527 6,249 5,888 5,847 5,587 5,200 4,837 4,534 4,126 

Peak Season Reserve Margins Peak Season Projected Resource Mix (Cumulative Change)

SERC-Southeast: Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 47,116 48,137 48,931 49,427 50,124 51,135 51,563 52,292 53,046 53,844

Demand Response 2,166 2,190 2,213 2,206 2,215 2,224 2,229 2,233 2,251 2,252

Net Internal Demand 44,950 45,947 46,718 47,221 47,909 48,911 49,334 50,059 50,795 51,592

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 60,035 60,461 60,522 62,109 62,978 63,124 63,120 62,943 62,927 63,068

Prospective 60,331 60,757 60,818 62,405 63,274 63,420 63,416 63,239 63,223 63,364

Adjusted-Potential 60,333 60,852 61,084 62,671 63,540 63,686 63,682 63,505 63,489 63,630

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 33.56% 31.59% 29.55% 31.53% 31.45% 29.06% 27.94% 25.74% 23.88% 22.24%

Prospective 34.22% 32.23% 30.18% 32.15% 32.07% 29.66% 28.54% 26.33% 24.47% 22.82%

Adjusted-Potential 34.22% 32.44% 30.75% 32.72% 32.63% 30.21% 29.08% 26.86% 24.99% 23.33%

Reference Margin Level 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 8,343 7,622 6,796 7,805 7,883 6,877 6,386 5,375 4,512 3,737 

Prospective 8,639 7,917 7,092 8,101 8,179 7,173 6,681 5,671 4,808 4,033 

Adjusted-Potential 8,641 8,013 7,358 8,367 8,445 7,439 6,947 5,937 5,074 4,299 

Peak Season Reserve Margins Peak Season Projected Resource Mix (Cumulative Change)

0%

5%

10%

15%

20%

25%

30%

35%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

10%

15%

20%

25%

30%

35%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-6

-5

-4

-3

-2

-1

0

1

2

3

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Nuclear Coal Hydro

0.0

0.5

1.0

1.5

2.0

2.5

3.0

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Coal Natural Gas Nuclear Renewables
SERC

NERC | 2014 Long-Term Reliability Assessment | November 2014

80

Demand, Resources, and Planning Reserve Margins

The Prospective Reserve Margins for all three SERC Assessment Areas remain above the Reference Margin Level of 15 percent 

throughout the assessment period. The Anticipated Reserve Margin for the SERC-E and SERC-N subregions falls below the 

Reference Margin Level in 2021 and 2023, respectively. The SERC demand forecast is expected to be lower than previous 

forecasts due to a number of factors, including lower economic growth.

DR, as well as energy efficiency and conservation programs, are projected to grow through 2020, after which some of these 

programs will plateau.

The SERC Assessment Area expects a number of changes to generation capabilities during the assessment period, including

additions of the following: (1) Lee Steam Combined-Cycle power station, (2) V.C. Summers, (3) Watts Bar, and (4) Vogtle 

Nuclear Stations. Planned retirements in SERC’s subregions are not expected to have any adverse impact on reliability; 

however, SERC entities continue to plan their system to address reliability needs to interconnect, deliver, and retire 

generating units.

There is a very limited amount of BTMG, DG, and variable energy resources (VERs) in SERC. The small existing amount of 

BTMG currently contracted (mostly solar) is incorporated into the load forecast. The impacts from this generation have been 

incorporated into the long-term plan as a reduction in the forecast demand, and it is expected that these types of resources 

will further reduce peak demand through impacts to the daily load shape. Due to the relative capacity and the operational 

nature of DG and VERs, expected on-peak capacity values in SERC are predictable and consistent.

All capacity transfers that are counted as capacity are backed by specific generation designations or transmission service 

reservations. SERC entities coordinate with their first-tier neighbors to ensure sufficient transmission interface capability, and 

to assess if potential impacts to capacity transfers exist due to any neighbors’ planned system modifications.

Specific areas within the SERC Assessment Area are known to have large penetrations of induction motor loads, which are 

one of the main drivers behind Fault-Induced Delayed Voltage Recovery (FIDVR). SERC entities perform annual studies to 

decrease potential FIDVR exposure by ensuring sufficient dynamic reactive sources are available in the potential exposure 

area. With current load forecast, SERC entities do not anticipate that any FIDVR-affected areas will impact system reliability 

during the long-term assessment period.

Transmission Outlook and System Enhancements

Several transmission projects are in progress to improve reliability within the SERC Assessment Area. To name a few, 

Southeast Voltage Project involves building a new 115 kV line from Bonifay to Chipley substations, and Gulf Coast Loop Project 

involves building a new 115 kV line from Southport to Bayou George substation to Gaskin Switching station. In addition, to 

enhance current carrying capability across the VACAR-Southern interface, a 230 kV circuit will be built between Purrysburg 

and McIntosh substations.

During the assessment period, Southern Company Inc. is planning to add two 100 MVar SVCs, and TVA is adding a [-150/+300 

MVar] SVC with an additional 250 MVar of caps controlled by this SVC to enhance voltage profile. Southern Company is 

developing and deploying smart grid technologies, including installing smart meters and an integrated distribution 

management system. These systems should provide better monitoring and enable quicker restoration in the event of storms 

or other damage. Southern also has several PMUs or the equivalent installed on the system and will add many more in the 

future. Several other SERC entities are deploying PMU, smart grid, and system awareness technology during the coming years. 

Duke Energy is working to integrate PMU information into the energy management systems. TVA is continuing with a program 

to install PMUs and GIC detectors across the Tennessee Valley.

Long-Term Reliability Issues

Shoulder (off-peak) periods, with lower network loading, reduced hydro generation, and significant resource maintenance 

outages, introduce a variety of challenges. During certain shoulder months and winter midday low-load periods, when solar 
SERC

NERC | 2014 Long-Term Reliability Assessment | November 2014

81

output is negatively correlated with load, operational concerns arise during these minimal load conditions. SERC entities are

currently studying the impacts of significant levels of potential solar penetration.

Retirements of generation in the SERC Assessment Area, some of which are caused by environmental regulations, are 

mitigated by gas-fired resources, purchase power agreements, and diversification of generation mix. SERC entities are 

optimistic that they can complete all necessary retrofits and improvements without sacrificing system reliability.

Entergy, with its six utility operating companies, and South Mississippi Electric Power Association, which previously reported 

data and information primarily in the SERC-W Assessment Area, integrated into MISO in December 2013. This shift added 

approximately 15,500 miles of transmission, 50,000 MW of generation capacity, and 35,000 MW of peak load to the MISO 

footprint. MISO now coordinates all RTO activities in the newly combined area, consisting of all or parts of 15 states.

Within this expanded MISO Balancing Area, the contract path capacity is limited to 1000 MW between the original MISO 

Central/North system and the new MISO South system. MISO market dispatches that result in power transfers between the 

MISO Central/North and MISO South portions of its system can result in significant unscheduled power flows through 

neighboring systems Tennessee Valley Authority (TVA), Associated Electric Cooperative, Inc. (AECI), Louisville Gas & Electric

Company and Kentucky Utilities Company (LG&E/KU), Power South, Southwest Power Pool, Inc. (SPP), and Southern 

Company. These neighboring systems have raised concerns regarding these power flows, especially if the market dispatches 

exceed the 2,000 MW transfer limit from MISO South to MISO Central/North. At this time, no long-term joint planning studies 

have been conducted to determine long-term transmission system impacts. MISO and the neighboring systems have begun 

to establish long-term arrangements for both reliable operations and coordinated planning. In addition, SERC regional studies 

groups are assessing and refining SERC modeling and reliability assessments to better reflect the expanded MISO BA in 

regional long-term planning and operational planning assessments. 

Prior to MISO starting merged market operations in December 2013, MISO and the neighboring systems developed an 

Operations Reliability Coordination Agreement (ORCA) to address reliability concerns during an initial operating transition 

period. The ORCA is set to expire in April 2015. MISO and their neighboring systems continue to explore other reliability 

processes to mitigate any adverse impacts on system reliability in the operational time frame.

Another potential emerging issue is that very long HVDC lines are being considered by independent transmission developers 

in economic projects such as shipping wind to the southeast. The capacity of a single line is typically greater than the largest 

single-contingency-generation loss in a system. The capacity of two poles will probably be larger than that of the largest multiunit generating plant. On very long lines, the risk of losing both poles may be appreciable, and that risk plus the high power 

level could impact reliability. An emerging issue may be the ability of present study criteria to adequately model the impact 

of these lines on a system.

Also, due to the current tax subsidies in North Carolina, a large number of solar qualifying facilities have been requested in 

the transmission queue. These projects create uncertainty in planning for various reasons, including the uncertainty of the 

projects actually coming to fruition (i.e., the companies being able to rely on the capacity and/or generation from these 

facilities) and the intermittent nature of solar.
NERC | 2014 Long-Term Reliability Assessment | November 2014

82

SPP

Assessment Area Overview

Southwest Power Pool (SPP) is a NERC Regional Entity (RE) that covers 370,000 square miles and encompasses all or parts of Arkansas, 

Kansas, Louisiana, Mississippi, Missouri, New Mexico, Oklahoma, and Texas, serving approximately 6.2 million households. The SPP Winter 

Assessment is reported based on the Planning Coordinator footprint. Along with the SPP RE footprint, it also includes Nebraska Public 

Power District, Omaha Public Power District, and Lincoln Electric System, which are registered with the Midwest Reliability Organization 

Regional Entity. The SPP Assessment Area footprint has 48,368 miles of transmission lines, 915 generating plants, and 6,408 transmissionclass substations.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

SPP established target of 13.6 percent

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Summer

Planning Considerations for Wind Resources

On-peak contribution of 3 percent of nameplate capacity

Planning Considerations for Solar Resources

On-peak contribution of 10 percent of nameplate capacity

Footprint Changes

Western Area Power Administration (WAPA) Upper Great Plains, 

Basin Electric, and Heartland Consumers Power District 

(Heartland) are expected to join the SPP Assessment Area and be 

fully integrated into SPP on October 1, 2015. The integration of 

these entities, primarily located in North and South Dakota, will 

add approximately 5,000 MW of load and 9,500 miles of 

transmission to the SPP RTO footprint.

Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 49,710 50,993 51,700 52,267 52,849 53,454 53,999 54,817 55,438 56,991

Demand Response 1,284 1,306 1,316 1,323 1,326 1,327 1,326 1,326 1,326 1,327

Net Internal Demand 48,426 49,687 50,384 50,944 51,523 52,128 52,673 53,491 54,112 55,663

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 65,942 64,539 65,247 65,258 65,394 64,945 64,949 64,693 64,579 63,634

Prospective 66,241 64,888 65,804 65,815 65,951 65,502 65,507 65,250 65,136 64,299

Adjusted-Potential 66,426 65,174 66,133 66,230 66,366 65,929 65,938 65,706 65,648 64,877

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 36.17% 29.89% 29.50% 28.10% 26.92% 24.59% 23.31% 20.94% 19.34% 14.32%

Prospective 36.79% 30.59% 30.60% 29.19% 28.00% 25.66% 24.37% 21.98% 20.37% 15.51%

Adjusted-Potential 37.17% 31.17% 31.26% 30.01% 28.81% 26.48% 25.18% 22.83% 21.32% 16.55%

Reference Margin Level 13.60% 13.60% 13.60% 13.60% 13.60% 13.60% 13.60% 13.60% 13.60% 13.60%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 10,930 8,094 8,011 7,386 6,864 5,728 5,113 3,927 3,108 400 

Prospective 11,228 8,443 8,568 7,943 7,421 6,285 5,670 4,484 3,665 1,066 

Adjusted-Potential 11,414 8,729 8,897 8,358 7,836 6,712 6,101 4,940 4,177 1,644 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

10%

15%

20%

25%

30%

35%

40%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Nuclear Renewables

Hydro Coal Petroleum
SPP

NERC | 2014 Long-Term Reliability Assessment | November 2014

83

Demand, Resources, and Planning Reserve Margins

Based on the 2014LTRA reference case, the Reserve Margins for the SPP Assessment Area will remain above the Reference

Margin Level of 13.6 percent for all seasons and years of the assessment period.

The SPP Assessment Area is showing approximately an 8 percent decrease in Total Internal Demand compared with the 

2013LTRA. This decrease is primarily due to several SPP members moving to the MISO footprint. Other drivers include a mild 

2013 summer and higher projected impacts from both energy efficiency and DR programs. Several SPP members have also 

reported load forecasts with decreased annual growth percentages, impacted by changing economic conditions during the 

past several years. The SPP Assessment Area continues to forecast modest average annual growth of approximately 3.5 

percent in energy efficiency and DR programs through 2024. DR programs in the SPP Assessment Area are voluntary and are 

primarily targeted for summer peak load reduction.

The High-Priority Incremental Load Study indicated that the SPP Assessment Area is experiencing an increase in oil and gas 

drilling, causing substantial load growth in northern Oklahoma, southwestern Kansas, Texas, and New Mexico. This localized 

growth has created the need for new transmission projects and generation in specific areas. SPP is working with its 

stakeholders to ensure that reliability needs are being addressed.

Approximately 3,150 MW of nameplate capacity are expected to be retired during the assessment period (with the inclusion 

of retirements in 2014). With approximately 7,500 MW of new nameplate capacity projected to come into service during the 

assessment period, there are no operational or planning concerns at this time. 

The expected on-peak capacity values for variable generation are determined by historical performance guidelines.

99 The net 

capability for wind is determined on a monthly basis using an eight-step process for establishing net capability. Wind facilities 

that have been in commercial operation for three years or less must include the most recently available engineering data. If 

MW values are not available, estimates may be used based on wind data that is correlated with reference towers outside a 

50-mile radius of the facility’s location. Such estimates must be approved by the SPP RTO Generation Working Group (GWG).

The net capability for solar resources is determined on a monthly basis using the same eight-step process as that of wind 

resources. Solar data that is correlated beyond 200 miles of the reference measuring device must also receive SPP GWG 

approval.

100

The SPP GWG’s proposed revisions to section 12.1.5.3.g of SPP Criteria (SPP Criteria), the Accreditation for Renewable 

Resource (Wind and Solar), were passed by the SPP Board of Directors at the July Meeting. The GWG’s intention was to ensure 

the accreditation process meets the SPP Assessment Area’s needs while not being overly cumbersome to the resource 

owners. The SPP GWG performed an analysis using operations data from the SPP footprint and sample data from 17 wind 

resources (varying wind turbine type, geographical location, and age of the facility). The GWG then applied this data to the 

existing SPP Criteria, proposed criteria language, and compared the results to a more rigorous ELCC study. The proposed 

language will now include the 3 percent top load hours, which will occur 60 percent of the time. It allows SPP members to 

apply more stringent criteria if desired by their area.

The GWG made these changes after extensive discussions and researching the operations data. The new proposed SPP 

Criteria covers accreditation for both wind and solar renewable resources, has a less-stringent confidence interval, and has

been benchmarked against solar operational data for the resources and detailed ELCC studies.

The SPP Assessment Area continually evaluates operational procedures to determine if efficiency and reliability 

improvements can be made. Because of the level of wind resources in the footprint, SPP has included some variable resources 

 

99 Section 12.

100 Facilities that have been in commercial operation for four years or more must include a minimum of four years or up to 10 years of the most recent 

commercial operation data available, whichever is greater. Metered hourly net power output (MWh) data may be used. After three years of commercial 

operations, if the Load-Serving Member does not perform or provide the net capability calculations to SPP, then the net capability for the resource will be 

0 MW. Net capability calculations are to be updated at least once every three years.
SPP

NERC | 2014 Long-Term Reliability Assessment | November 2014

84

into its automatic, security-constrained dispatch calculations. This allows the SPP Assessment Area to better manage local 

congestion issues for which wind is the primary impacting resource. SPP is now able to better manage system reliability by 

using quicker and more effective control actions. New wind installations are required to be dispatchable.

SPP Assessment Area members, along with some members of the SERC Region, jointly participate in a Reserve Sharing Group

(RSG). Members of the RSG receive contingency reserve assistance from each other and do not require support from 

generation resources outside the RSG. The SPP Operating Reliability Working Group sets the Minimum Daily Contingency 

Reserve Requirement for the RSG.

Long-Term Reliability Issues

Drought and flooding conditions are the most impactful weather events within the SPP Assessment Area. Current drought 

conditions in the western portion of the SPP Assessment Area are projected to continue into the assessment period. Most of 

the SPP Assessment Area’s heavily water-dependent resources are located in the eastern half of the footprint, which has also 

experienced drought conditions in the past. SPP planning staff is studying the potential impacts of drought conditions in the 

SPP Assessment Area. The 2015 Integrated Transmission Planning (ITP) 10-year study includes a future scenario with a 

decreased baseload capacity in which units susceptible to drought conditions are derated or retired.

SPP’s Operational Planning group performs biannual system planning studies to capture the potential reliability impacts of 

retirements and retrofits of generation. Any identified reliability concerns are passed to the SPP RTO long-term planning 

group. This study process consists of the creation of weekly snapshots through the next four years that consider load forecasts

and known transmission and generation outages. Local issues are reported to the impacted SPP Transmission Operators. 

Since the SPP Assessment Area has sufficient capacity, the impacts of long-term maintenance outages are expected to be 

more economic in nature. Current studies indicate there will be adequate time to perform generator retrofits necessary to 

comply with current known environmental regulations. These currently planned retrofits are expected to impact generation 

supply economics more than the ability to reliably serve load. SPP continues to monitor and evaluate the impacts of generator

retirements resulting from environmental regulations in its planning studies. SPP’s 2015 ITP 10-year study included 

assumptions about generator retirements that were expected at the time the models were built for that study. After the ITP 

10-year study began, the EPA issued its proposed Clean Power Plan on June 2, 2014. SPP is concerned about the reliability 

implications of additional generator retirements that could result from new regulations included in that proposed rule. Any 

additional retirements resulting from these new regulations have not yet been included in SPP’s planning processes and will 

need to be thoroughly studied to ensure that any resulting reliability impacts are properly addressed.

SPP, along with other joint parties in the Region and MISO, are currently managing reliability concerns from MISO’s recent 

operational changes under the provisions of the Operations Reliability Coordination Agreement (ORCA). Under Phase 1 of the 

ORCA, unless otherwise agreed to by the joint parties, MISO transfers between MISO Central/North and MISO South are 

limited. The joint parties and MISO continue to work to develop, test, and implement subsequent phases of the ORCA that 

would allow this reliability limit to potentially increase under certain conditions. 

SPP will not impede reliability by limiting the exchange of energy between MISO Central/North and MISO South except as 

required for SPP to maintain its own reliable operations, even if it requires MISO to exceed their current 1,000 MW path. 

While SPP and MISO are currently in litigation over the terms and conditions of the compensation due to SPP when MISO 

may exceed its 1,000 MW path, the two assessment areas continue to work together to ensure reliable operation.

SPP and MISO have also recently agreed to improvements to the method for accounting for the flow impacts of import and 

export transactions used in the congestion management process. SPP and MISO continue to discuss additional improvements 

to ensure all sources of flows are properly accounted for within the Region. SPP is currently working with MISO to implement 

a market-to-market congestion management process that will serve to enhance reliability by more efficiently responding to 

congestion that occurs on flowgates impacted by both RTOs. It is expected that the market-to-market process will be in place 

by March 1, 2015.
NERC | 2014 Long-Term Reliability Assessment | November 2014

85

TRE-ERCOT

Assessment Area Overview

The Electric Reliability Council of Texas (ERCOT) is the Independent System Operator (ISO) for the ERCOT Interconnection and is located 

entirely in the state of Texas; it operates as a single BA. ERCOT is a summer-peaking Region that covers approximately 200,000 square 

miles, connects 40,530 miles of transmission lines and 566 generation units, and serves 23 million customers. The Texas Reliability Entity 

(Texas RE) is responsible for the RE functions described in the Energy Policy Act of 2005 for the ERCOT Region.

Summary of Methods and Assumptions Assessment Area Footprint

Reference Margin Level

ERCOT established Reference Margin of 13.75 percent

Load Forecast Method

Coincident; normal weather (50/50)

Peak Season

Summer

Planning Considerations for Wind Resources

Effective Load-Carrying Capability (ELCC) of 8.7 percent

Planning Considerations for Solar Resources

ERCOT incorporates 100 percent capacity contribution

Footprint Changes

N/A

Peak Season Demand, Resources, and Reserve Margins101

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 69,057 70,014 70,871 71,806 72,859 73,784 74,710 75,631 76,550 77,471

Demand Response 1,917 1,917 1,917 1,917 1,917 1,917 1,917 1,917 1,917 1,917

Net Internal Demand 67,140 68,097 68,954 69,889 70,942 71,867 72,793 73,714 74,634 75,554

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 76,751 77,673 78,478 79,360 78,760 78,760 79,060 79,060 79,060 79,060

Prospective 79,574 81,486 82,991 84,361 84,972 85,343 86,014 86,384 86,755 87,126

Adjusted-Potential 79,574 81,588 83,172 84,580 85,251 85,621 86,292 86,663 87,033 87,404

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 14.31% 14.06% 13.81% 13.55% 11.02% 9.59% 8.61% 7.25% 5.93% 4.64%

Prospective 18.52% 19.66% 20.36% 20.71% 19.78% 18.75% 18.16% 17.19% 16.24% 15.32%

Adjusted-Potential 18.52% 19.81% 20.62% 21.02% 20.17% 19.14% 18.54% 17.57% 16.61% 15.68%

Reference Margin Level 13.75% 13.75% 13.75% 13.75% 13.75% 13.75% 13.75% 13.75% 13.75% 13.75%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 379 212 43 (139) (1,937) (2,989) (3,742) (4,790) (5,836) (6,882)

Prospective 3,203 4,025 4,556 4,863 4,275 3,594 3,212 2,534 1,859 1,183 

Adjusted-Potential 3,203 4,127 4,737 5,081 4,554 3,873 3,490 2,813 2,138 1,462 

Peak Season Reserve Margins Projected Peak Season Generation Mix (Cumulative Charge)

 

101 The Frontera power plant (three natural-gas-fired units totaling 524 MW) is assumed to be available to serve peak load for all years in the 2014LTRA 

Reference Case. However, the plant’s owner recently announced plans to begin exporting 170 MW of capacity to Mexico as soon as 2015, and the entire 

524 MW in 2016 with the completion of certain transmission projects. ERCOT and the Frontera Facility’s owners have agreed on the reliability safeguards 

for ensuring the plant will be available if needed in an emergency and have filed those conditions with the U.S. Department of Energy as part of the 

plant’s export authorization.

0%

3%

6%

9%

12%

15%

18%

21%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Renewables Coal
TRE-ERCOT

NERC | 2014 Long-Term Reliability Assessment | November 2014

86

Demand, Resources, and Planning Reserve Margins

New gas-fired resources totaling 2,112 MW (summer rating) being added during the summer of 2014 help elevate the 

Anticipated Reserve Margin to 14.3 percent in 2015. The Anticipated Reserve Margin is expected to remain above the 

Reference Margin Level of 13.75 percent until 2018, while the Prospective Reserve Margin remains above the Reference 

Margin Level for the entire assessment period. The expected addition of the Panda Temple II combined-cycle plant (717 MW 

summer rating) in August 2015 and the FGE Texas 1 combined-cycle plant (703 MW summer rating) in July 2016 largely offset 

forecast load growth through 2017. After 2017, there is insufficient Anticipated resources to keep pace with load growth. 

The generation market in ERCOT is unregulated, with generators making resource decisions based on market dynamics as 

well as administratively applied scarcity pricing mechanisms intended to incentivize the provision of adequate operating 

reserves. In an environment of continuing economic and load growth, tight reserve margins are expected beyond three to 

four years in the future, given the lead time for proposed resources to proceed through ERCOT’s interconnection request 

process and meet ERCOT’s requirements for inclusion in resource adequacy assessments. If there is a risk of insufficient 

capacity to meet resource adequacy requirements in the short-term future, the Public Utility Commission of Texas (PUCT), 

with input from ERCOT and market participants, would be expected to investigate and implement measures to address 

potential capacity shortages.

As a temporary measure to address system reliability problems stemming from generators that are planned to be taken out 

of service by their owners, ERCOT can enter into Reliability Must-Run (RMR) contracts with those generators or others that 

would otherwise not operate.

The ERCOT peak demand forecast (Total Internal Demand) for summer 2015 is 69,057 MW and is expected to occur in early 

August. The 2015 peak demand forecast is 1.4 percent higher than the forecast for 2014, driven in part by the continued 

expansion of oil and gas production in the Permian Basin and Eagle Ford Shale areas, but is 3.4 percent lower than the 2015 

forecast reported in the 2013LTRA. This decrease is due to major changes to ERCOT’s load forecast method that better 

capture the relationship between economic indicators and electric demand, as well as the impacts of energy efficiency and 

other efforts by industrial and commercial sector customers to reduce electricity usage during periods of high demand.

With respect to the TRE-ERCOT Region’s reliance on DSM programs, significant growth has recently occurred for ERCOT’s 

Emergency Response Service (ERS). This program, which includes 10- and 30-minute Demand Response resources as well as 

distributed generation service, is designed to be deployed in the late stages of a grid emergency, prior to shedding involuntary 

Firm load. Procurement of ERS summer peak time period procurement grew from 422 MW in 2013 to 626 MW in 2014, nearly 

a 50 percent increase. The ERS program remains capped at $50 million per year, in accordance with an existing rule 

implemented by the PUCT. This spending cap is expected to cause the growth rate to flatten during the next few years. Load 

Resource capacity providing ancillary services is also expected to increase due to new rules enabling Controllable Load 

Resources to bid into the real-time market for the provision of non-spinning reserves. ERCOT also accounts for the peak load 

impacts of Demand Response programs managed by several Transmission Service Providers (TSPs). These TSPs have individual 

contractual programs with loads that can respond to instructions to reduce total energy usage. These programs are expected

to remain flat for the foreseeable future at approximately 240 MW.

A significant amount of generating capacity has been added since 2013, and more is expected in 2014 and 2015. These 

additions have entered commercial operations and are listed below:

 Sandy Creek 1 (coal-fired, 970 MW) 

 WA Parish addition (gas-fired, 74 MW) 

 Acacia Solar (solar PV, 10 MW)

 OCI Alamo 1 (solar PV, 39 MW) 

 Blue Summit Wind 5 and 6 (135 MW)

 Los Vientos Wind I and II (402 MW)
TRE-ERCOT

NERC | 2014 Long-Term Reliability Assessment | November 2014

87

ERCOT forecasts 2,801 MW of new summer-rated capacity to be available for the 2015 summer peak load. Out of this total, 

2,144 MW are gas-fired, 489 MW are wind, and 168 MW are solar PV facilities. 

Natural-gas-fired additions in 2014 include: two new combined-cycle gas-fired power plants (Panda Sherman and Panda 

Temple 1) with a combined summer capacity rating of 1,437 MW; the 510 MW Ferguson combined-cycle plant, which 

replaced the original 354 MW unit (retired in September 2013); a 165 MW (summer rating) expansion of the Deer Park Energy 

Center; and two small plant upgrade projects for a total of 32 MW. New renewable resources available for the 2015 summer 

peak load include three solar PV plants: White Camp Solar 1 (100 MW nameplate), Pecos Barilla Solar (30 MW nameplate), 

OCI Alamo 4 (38 MW nameplate), and 30 wind plants for a total of 5,625 MW nameplate capacity. The wind plant sizes range 

from 68 to 600 MW. 

Regarding units planned for retirement or suspended operations, NRG recently announced that its five S.R. Bertron gas-fired 

units (combined summer rating of 727 MW) will not return from mothball status for summer operation. Additionally, the J.T. 

Deely coal plant (840 MW) is expected to enter indefinite mothball status at the end of 2018.

The TRE-ERCOT Region is a separate interconnection with only asynchronous ties to SPP and Mexico’s Comisión Federal de 

Electricidad (CFE). As such, ERCOT does not share reserves with other Regions. There are two asynchronous ties between 

ERCOT and SPP with a total of 820 MW of transfer capability, and four asynchronous ties between ERCOT and Mexico with a 

total of 436 MW of transfer capability (once the Sharyland Utilities expansion project (150 MW) was expected to be

completed in 2014). For the assessment period, ERCOT assumes that all of the generating capacity of the Tenaska Kiamichi 

Generating Station (1,246 MW summer rating and 1,330 MW winter rating) located in Pittsburgh County, Oklahoma, is 

dedicated to the ERCOT market. Also included in the assessment is 463 MW of import capability determined by analyzing 

historical flows across the dc ties during peak hours.

Transmission Outlook and System Enhancements

With respect to transmission planning, the recently updated ERCOT future transmission projects list includes the addition or 

upgrade of 1,602 miles of 138 kV and 345 kV transmission circuits, 7,472 MVA of 345/138 kV autotransformer capacity, and 

5,538 MVar of reactive capability projects that are planned in ERCOT between 2014 and 2023. Sixty-four projects were 

identified as being necessary to meet the system needs in West Texas through 2017. A new Houston Import Project consisting 

of a 130-mile 345 kV double circuit line from Limestone to Gibbons Creek to Zenith is planned to be in service before the 

summer peak of 2018. Other significant projects include a new 345 kV import line and an upgrade of the two existing 345 kV

import lines to support load growth in the Lower Rio Grande Valley (LRGV), a new Cross Valley 345 kV, 106-mile line to support 

load growth in Brownsville and other cities along the eastern side of the LRGV, and multiple transmission upgrades in the 

Odessa North area (west Texas). ERCOT has received requests to study two projects that would add asynchronous tie capacity 

between ERCOT and the Eastern Interconnection. The Southern Cross project would connect on the eastern portion of the 

ERCOT system and add up to 3,000 MW of tie capacity by 2016. The Tres Amigas project would add 1,500 MW of tie capacity

in the Texas Panhandle by 2017. These new lines will provide access to several Regions adjacent to ERCOT. The additional dc

tie capacity is being proposed for commercial purposes.

Long-Term Reliability Issues

New and proposed federal environmental regulations continue to be a concern from a long-term resource adequacy 

perspective. ERCOT is monitoring the impacts of multiple proposed federal environmental regulations, including CSAPR and 

MATS. The U.S. Supreme Court affirmed the U.S. Environmental Protection Agency’s authority to promulgate the CSAPR on 

April 29, 2014. ERCOT is analyzing the implications of the Supreme Court’s decision and will work closely with TRE-ERCOT 

Region generators to assess the impact of CSAPR implementation on resource adequacy and grid reliability once updated 

proposed regulations are issued. For MATS, survey data collected from ERCOT’s solid fuel generators in mid-2013 indicated 

that while unit retirements are not an immediate concern, a number of generators that are not currently in compliance with 

the standard, representing about 32 percent of all the capacity covered by the survey, did not have their compliance strategies 

finalized. As with CSAPR, ERCOT will continue to closely monitor MATS compliance efforts and assess the risk for unit 
TRE-ERCOT

NERC | 2014 Long-Term Reliability Assessment | November 2014

88

retirements. Other proposed regulations being monitored by ERCOT include the Cooling Water Intake Structures Rule (under 

Section 316(b) of the Clean Water Act), the Coal Ash Disposal Rule (under the Resource Conservation and Recovery Act 

(RCRA)), the Steam Electric Effluent Limitation Guidelines, and CO2 emission regulations from existing plants. All of these 

proposed regulations are not expected to have a material impact on reliability for the next two to three years if enacted. 

However, their combined impact on coal plant economic viability further out in the assessment period may become an issue 

if significant retired coal plant capacity is the resulting outcome. 

From an operational perspective, the combination of a large seasonal variance in system load and the high penetration of 

wind generation has increased challenges for voltage support and frequency control, particularly during large ramp events. 

Nevertheless, ERCOT has been successfully operating the system with high wind penetration over the past few years. To 

address these new challenges, ERCOT has proposed the phased implementation of a redesigned ancillary services framework 

consisting of new and revised unbundled ancillary services products intended to take advantage of evolving system needs 

and capabilities of existing resources, as well as emerging technologies such as battery storage. New ancillary services

products include Synchronous Inertial Response Service, Fast Frequency Response Service, and Primary Frequency Response 

Service. To implement the ancillary services framework, a Future Ancillary Services Team (FAST) has been established to 

facilitate stakeholder input and address substantive implementation issues prior to ERCOT’s development of proposed 

market protocol revisions later in 2014.

102

Finally, multi-year droughts in Texas continue to represent a reliability concern. Much of central Texas and the panhandle are 

currently under “exceptional” or “extreme” drought conditions, although reservoir levels are not expected to drop below 

power plant physical input limits during the remainder of 2014. If drought conditions extend into 2015, there is the risk of 

multiple resources being taken off-line due to the lack of cooling water. If operational restrictions extend over peak load

periods, resource adequacy then becomes an issue. Depending on the location of the drought, local area transmission 

congestion can result and must be relieved. If an extended drought occurs, additional transmission may need to be added to 

support an affected area. The entire system would be impacted by additional pressure placed on other resources. The specific 

location with the outage may have congestion problems to overcome in addition to voltage support issues.

 

102 Concept Paper: Future Ancillary Services in ERCOT.
NERC | 2014 Long-Term Reliability Assessment | November 2014

89

WECC

Assessment Area Overview

The Western Electricity Coordinating Council (WECC) is responsible for coordinating and promoting BES reliability in the Western 

Interconnection. WECC’s 329 members, which include 38 BAs, represent a wide spectrum of organizations with an interest in the BES. 

Serving an area of nearly 1.8 million square miles and approximately 82 million people, it is geographically the largest and most diverse of 

the NERC Regions. WECC’s service territory includes the Canadian provinces of Alberta and British Columbia, the northern portion of Baja 

California in Mexico, and all or portions of the 14 western states between. The WECC Assessment Area is divided into four subregions:103

Northwest Power Pool (NWPP), Rocky Mountain Reserve Group (RMRG), Southwest Reserve Sharing Group (SRSG), and California/Mexico 

(CA/MX). These subregional divisions are structured around Reserve Sharing groups that have similar annual demand patterns as well as 

similar operating practices.

Summary of Methods and Assumptions Assessment Area Footprints (CA/MX, NWPP, RMRG, SRSG)

Reference Margin Level

Determined by WECC’s building block method for each subregion.

Load Forecast Method

Coincident (Western Interconnection); normal weather (50/50)

Peak Season

Summer: CA/MX; RMRG; SRSG

Winter: NWPP

Planning Considerations for Wind Resources

Modeling, primarily based on historic data

Planning Considerations for Solar Resources

Modeling, primarily based on historic data

Footprint Changes

In early 2014, the Nevada Power and Sierra Pacific BAs were 

consolidated into one BA (Nevada Power) and incorporated into

the NWPP subregion, and the old Nevada Power BA was removed 

from the SRSG subregion.

 

103 Northwest Power Pool, Rocky Mountain Reserve Group, Southwest Reserve Sharing Group.
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WECC-CA/MX: Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 57,606 56,767 57,004 57,245 57,580 58,003 58,257 58,542 58,742 58,930

Demand Response 1,996 2,019 2,055 2,081 2,132 2,184 2,236 2,287 2,339 2,389

Net Internal Demand 55,610 54,748 54,949 55,164 55,448 55,819 56,021 56,255 56,403 56,541

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 64,102 63,531 63,670 63,675 64,014 64,383 64,576 64,289 64,470 64,106

Prospective 64,126 64,327 65,205 65,951 67,431 68,441 68,744 68,462 68,646 68,285

Adjusted-Potential 64,126 64,327 65,225 65,998 67,478 68,541 68,847 68,565 68,748 68,387

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 15.27% 16.04% 15.87% 15.43% 15.45% 15.34% 15.27% 14.28% 14.30% 13.38%

Prospective 15.31% 17.50% 18.66% 19.55% 21.61% 22.61% 22.71% 21.70% 21.71% 20.77%

Adjusted-Potential 15.31% 17.50% 18.70% 19.64% 21.70% 22.79% 22.89% 21.88% 21.89% 20.95%

Reference Margin Level 15.02% 15.02% 15.02% 15.02% 15.02% 15.02% 15.02% 15.02% 15.02% 15.02%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 139 559 467 226 238 180 141 (415) (405) (927)

Prospective 164 1,356 2,003 2,501 3,655 4,238 4,309 3,758 3,771 3,251 

Adjusted-Potential 164 1,356 2,022 2,549 3,702 4,338 4,412 3,860 3,874 3,354 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

WECC-NWPP: Peak Season Demand, Resources and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 70,778 71,786 73,217 74,430 75,490 76,482 77,422 78,320 79,189 79,912

Demand Response 325 325 325 325 325 325 325 325 325 325

Net Internal Demand 70,453 71,461 72,892 74,105 75,165 76,157 77,097 77,995 78,864 79,587

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 82,304 83,592 85,197 86,683 87,910 88,927 90,037 91,090 92,109 93,002

Prospective 83,217 85,075 86,863 88,422 89,660 90,677 91,819 92,898 93,918 93,002

Adjusted-Potential 83,246 85,191 87,045 88,789 90,106 91,215 92,357 93,437 94,519 93,661

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 16.82% 16.98% 16.88% 16.97% 16.96% 16.77% 16.78% 16.79% 16.79% 16.86%

Prospective 18.12% 19.05% 19.17% 19.32% 19.28% 19.07% 19.09% 19.11% 19.09% 16.86%

Adjusted-Potential 18.16% 19.21% 19.42% 19.81% 19.88% 19.77% 19.79% 19.80% 19.85% 17.68%

Reference Margin Level 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 4,101 4,270 4,287 4,426 4,478 4,393 4,460 4,516 4,570 4,660 

Prospective 5,014 5,753 5,953 6,166 6,227 6,143 6,241 6,324 6,379 4,660 

Adjusted-Potential 5,043 5,870 6,135 6,532 6,673 6,681 6,780 6,863 6,980 5,319 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

10%

12%

14%

16%

18%

20%

22%

24%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

10%

12%

14%

16%

18%

20%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-1

0

1

2

3

4

5

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Renewables

Petroleum Pumped Storage

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Coal Hydro Renewables
WECC

NERC | 2014 Long-Term Reliability Assessment | November 2014

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WECC-RMRG: Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 9,899 10,100 10,239 10,410 10,558 10,709 10,843 10,901 11,046 11,249

Demand Response 557 567 576 586 592 602 611 620 627 633

Net Internal Demand 9,342 9,533 9,663 9,824 9,966 10,107 10,232 10,281 10,419 10,616

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 15,106 15,088 15,814 15,681 15,249 15,002 13,139 11,647 11,820 12,028

Prospective 15,106 15,089 15,856 15,723 15,292 15,045 13,182 11,690 11,863 12,070

Adjusted-Potential 15,106 15,089 15,856 15,723 15,292 15,045 13,185 11,693 11,866 12,073

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 41.71% 58.27% 63.65% 59.62% 53.01% 48.43% 28.41% 13.29% 13.45% 13.30%

Prospective 41.71% 58.28% 64.09% 60.05% 53.44% 48.86% 28.83% 13.71% 13.86% 13.70%

Adjusted-Potential 41.71% 58.28% 64.09% 60.05% 53.44% 48.86% 28.86% 13.73% 13.88% 13.73%

Reference Margin Level 13.20% 13.20% 13.20% 13.20% 13.20% 13.20% 13.20% 13.20% 13.20% 13.20%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 4,531 4,297 4,875 4,560 3,968 3,561 1,556 9 26 10 

Prospective 4,531 4,297 4,918 4,603 4,010 3,604 1,599 52 68 53 

Adjusted-Potential 4,531 4,297 4,918 4,603 4,010 3,604 1,602 55 71 56 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

WECC-SRSG: Peak Season Demand, Resources, and Reserve Margins

Demand (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Total Internal Demand 22,635 22,760 23,282 23,762 24,335 24,707 25,113 25,694 26,193 26,709

Demand Response 418 421 430 372 377 382 382 382 382 383

Net Internal Demand 22,217 22,339 22,852 23,390 23,958 24,325 24,731 25,312 25,811 26,326

Resources (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 29,289 30,904 29,958 29,992 28,991 28,469 28,459 28,895 28,843 29,536

Prospective 29,413 31,092 30,190 30,223 29,258 28,771 28,846 29,317 29,300 30,066

Adjusted-Potential 29,473 31,208 30,320 30,405 29,443 28,979 29,098 29,598 29,609 30,448

Reserve Margins (%) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 31.83% 38.35% 31.10% 28.22% 21.01% 17.03% 15.08% 14.16% 11.75% 12.19%

Prospective 32.39% 39.19% 32.11% 29.21% 22.12% 18.27% 16.64% 15.82% 13.51% 14.21%

Adjusted-Potential 32.66% 39.71% 32.68% 29.99% 22.89% 19.13% 17.66% 16.93% 14.72% 15.66%

Reference Margin Level 14.06% 14.06% 14.06% 14.06% 14.06% 14.06% 14.06% 14.06% 14.06% 14.06%

Excess/Shortfall (MW) 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated 3,949 5,425 3,893 3,313 1,665 724 252 24 (597) (492)

Prospective 4,072 5,613 4,125 3,544 1,932 1,025 638 446 (141) 38 

Adjusted-Potential 4,133 5,729 4,255 3,726 2,116 1,234 890 727 169 420 

Peak Season Reserve Margins Peak Season Projected Generation Mix (Cumulative Change)

0%

10%

20%

30%

40%

50%

60%

70%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

10%

15%

20%

25%

30%

35%

40%

45%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Prospective

Adjusted-Potential Reference Margin Level

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Coal Hydro

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Gigawatts

Natural Gas Coal Petroleum Renewables
WECC

NERC | 2014 Long-Term Reliability Assessment | November 2014

92

Demand, Resources, and Planning Reserve Margins

Throughout the 10-year assessment period, the Reference Margin Levels range between 11 and 15 percent for the four 

subregions. The Reference Margin Levels

104 for each subregion are calculated using a building block method105 created by 

WECC’s Reliability Assessment Work Group (RAWG),106 formerly Loads and Resources Subcommittee, for its annual Power 

Supply Assessment (PSA).107 The elements of the building block margin calculation are consistent from year to year, but the 

calculations may have slight annual variances by region and subregion. 

By the summer of 2024, the difference between WECC’s Prospective Resources (198,259 MW) and WECC’s Net Internal 

Demand (169,314 MW) is calculated as 28,945 MW (17.1 percent margin). As the expected resources exceed the Reference 

Margin Levels, it is reasonable to assume that only a portion of the reported resource additions will ultimately enter 

commercial service within the planning horizon. 

As depicted in the graphic at the beginning of this section, the reserve margins for the WECC subregions remain above the

Reference Margin Levels through 2021. Beginning in 2022, individual subregions do drop below their Reference Margin 

Levels, but the potential resource additions that have been reported exceed these possible shortages. 

In the resource adequacy process, each BA is responsible for complying with the resource adequacy requirements of the state 

or provincial areas in which they operate. Some BAs perform resource adequacy studies as part of their integrated resource 

plans, which usually provide a 20‐year outlook. Other BAs perform resource adequacy studies that focus on the very short 

term (i.e., one to two years), but most projections provide at least a 10‐year outlook. WECC’s PSA uses a study period of 10 

years and the same subregional reserve target margins throughout the entire period. 

Similar to WECC’s PSA, resources that are energy‐only or energy‐limited (e.g., the portion of wind resources that is not 

projected to provide generation at the time of peak) are not counted toward meeting resource adequacy in this assessment. 

Also, resources such as DERs or BTMG that are not monitored by the BA’s energy management systems are excluded from 

the resource adequacy calculation.

Total Internal Demand for the summer, the peak season for the entire WECC Region, increased by 1.1 percent from 2012 to 

2013, mostly due to warmer than normal temperatures in 2013. The Total Internal Demand for the summer seasons during 

the next 10 years is projected to increase by 1.0 percent per year, which is a decrease from the 1.7 percent projected in the 

2013LTRA (2014–2023). The annual energy load is projected to increase by 1.2 percent per year for the 2015–2024 time 

frame, which is also a decrease from the 1.5 percent projected in the 2013LTRA.

The WECC Total Internal Demand forecast includes summer Demand Response that varies from 3,878 MW in 2015 to 4,226 

MW in 2024. The direct control DSM capability is located mostly in the California/Mexico subregion, totaling 1,996 MW in 

2015 and 2,389 MW in 2024. DSM programs in other subregions are also increasing. The most prevalent Demand Response 

programs in WECC involve air conditioner cycling as well as Interruptible Load programs that focus on the demand of large 

water-pumping operations and large industrial operations (e.g., mining). Currently, the most significant Demand Response

development activity within WECC is taking place in California; the California ISO (CAISO) is actively engaged with stakeholders 

in developing viable wholesale Demand Response products with direct market participation capability. Also of note is CAISO’s 

 

104 The NERC Reference Margin Level and all reserve margins are for planning purposes. Firm load would not be disrupted to maintain these margins. 

Rather, the margins are reference points that indicate areas that have lower reserves and tighter margins. The tighter margins are not forecasts of 

resource shortages. However, areas with tighter margins have a higher possibility, although not likelihood, of resource shortages associated with extreme 

events such as record-setting temperature deviations.

105 Elements of the Building Block Target are detailed in the NERC: Long-Term Assessment – Methods and Assumptions report.

106 All of the BAs within the Western Interconnection provided the generation data for this assessment, and WECC staff—under the direction of the WECC 

RAWG—processed the data. The reported generation additions generally reflect extractions from generation queues.

107 WECC's Power Supply Assessments.
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NERC | 2014 Long-Term Reliability Assessment | November 2014

93

Demand Response product implementation that facilitates the participation of existing retail demand programs in the CAISO 

market. Further information regarding these initiatives is available on CAISO’s website.108

Overall Demand Response program growth has been rather static and is not expected to increase dramatically during the 10-

year planning horizon. The various DSM programs within WECC are treated as load modifiers that reduce Total Internal 

Demand when calculating planning margins. In some situations, these programs may be activated by Load-Serving Entities 

(LSEs) during high-power cost periods but in general are only activated during periods in which local power supply issues 

arise. Generally, Demand Response programs in WECC have limitations, such as having a limited number of times they can 

be activated.109

Distributed energy resources, including rooftop solar and BTMG, currently represent a very small portion of both the existing 

and planned resources. As the load served by BTMG is not included in the actual or forecast peak demands and energy loads, 

these resources are excluded from the resource adequacy calculation. 

A few utilities attributed coal‐fired plant retirements and fuel conversions to existing air emissions regulations. Based on news 

media accounts and information related to western coal‐fired plant environmental regulation cost exposure, it is expected 

that future LTRA information will report additional retirements and fuel conversions as more plant owners establish their 

preferred approaches for addressing emission regulations. California regulations essentially specify that existing long-term 

contracts with coal-fired plants will be allowed to run to expiration, though not be renewed.110This regulation may result in 

the sale, retirement, or repowering of some power plants during the assessment period. Due to the somewhat fluid situation 

in California regarding retirements associated with once‐through cooling (OTC) regulations, potential associated capacity 

reductions have not necessarily been reported for this year’s LTRA for all potentially affected plants. Current information 

regarding the California OTC is available on the California Energy Commission’s website.111 It is expected that any future 

capacity reductions will be offset by new plants that may or may not be reflected in the current conceptual resources data. 

The Anticipated Resources projected for the 2015 summer peak period total 188,221 MW and reflect the monthly shaping of 

variable generation and the seasonal ratings of conventional resources. The expected on-peak capacity modeling for wind 

resources is based on curves created using at least five years of actual hourly wind generation data. The data is averaged into 

six four-hour blocks for each day of each week of the year. Solar resource energy curves were created using up to five years 

of actual hourly solar generation data. The data is averaged into three block curves for each day of the week of the year. 

Hydro generation is dispatched economically, limited by expected annual energy generated during an adverse hydro year. 

Biomass and geothermal capabilities are based on nominal plant ratings. The individual BAs report 37,410 MW as the total 

gross future capacity projected to be in service by the end of this assessment period. 

Greater wind generation has resulted in an increased fluctuation in instantaneous generation and a need for increased 

operating reserves to compensate for the wind‐induced fluctuations. Improved wind forecasting procedures and reduced 

scheduling intervals are methods that have only partially addressed the wind variability issue. Increased wind generation has 

also exacerbated high-generation issues in the Bonneville Power Administration (BPA) area during light load and high 

hydroelectric generation conditions. BPA is working on long‐term solutions to this issue and provides current information on 

its website.112 Increased wind penetration is expected to worsen the operating reserve situation. Solar generation may also 

 

108 California ISO Demand Response Initiatives.

109 NERC’s assessment process assumes that Demand Response may be shared among LSEs, BAs, and subregions. However, demand-side management 

sharing is not a contractual arrangement. Consequently, reserve margins may be overstated as they do not reflect Demand Response that could 

potentially be unavailable to respond to external energy emergencies. Energy efficiency and conservation programs vary by location and are generally 

offered by the load serving entities. The reduction to demand associated with these programs is reflected in the load forecasts supplied by the balancing 

authorities.

110 CEC Emission Performance Standards.

111 CEC Once-Through Cooling.

112 BPA Wind Activities.
WECC

NERC | 2014 Long-Term Reliability Assessment | November 2014

94

reach a level sufficient to add to the operational issues relative to short-term (sub-hourly) load following. A joint 

NERC/California ISO report addresses this potential operational issue.113

WECC does not rely on imports from outside the Region when calculating peak demand reliability margins. The Region also 

does not model exports to areas outside of WECC. However, imports may be scheduled across three back‐to‐back dc ties with 

SPP and five back‐to‐back dc ties with Assessment Areas in MRO. 

Inter‐subregional transfers are derived from resource allocation computer simulations that incorporate transmission 

constraints among various path‐constrained zones within WECC.114 The WECC resource allocation model places conservative 

transmission limits on paths between 19 load groupings (zones) when calculating the transfers between these areas. These 

load zones were developed for WECC’s PSA studies. The aggregation of PSA load zones into WECC subregions may obscure 

differences in adequacy or deliverability between zones within the subregion. 

The resource data for the individual subregions includes transfers between subregions that either are plant‐contingent 

transfers or reflect projected transfers with a high probability of occurrence. Plant‐contingent transfers represent both joint 

plant ownership and plant‐specific transfers from one subregion to another. Projected transfers reflect the potential use of 

seasonal demand diversity between the winter‐peaking NWPP and the summer‐peaking SRSG, as well as other economy and 

short‐term purchases that may occur between subregions. 

While these transactions may not be contracted, they reflect a reasonable modeling expectation given the history and 

extensive activity of the western markets, as well as the otherwise underused transmission from the Northwest to the other 

subregions.115 When examining all Adjusted-Potential Resources, all subregions maintain adequate reserves (above 

respective targets) throughout the assessment period.

Transmission Outlook and System Enhancements

WECC is spread over a wide geographic area, with significant distances between generation and load centers. In addition, the 

northern portion of the Assessment Area is winter peaking, while the southern portion of the assessment area is summer

peaking. Consequently, entities within the Western Interconnection may seasonally exchange significant amounts of surplus 

electric energy. These conditions result in periodic full utilization of numerous transmission lines, which does not adversely 

impact reliability. 

To help monitor the impact of new generation resources on the transmission systems, individual entities within the Western 

Interconnection have established generator interconnection requirements that include power flow and stability studies to 

identify any adverse impact from proposed projects. In addition, WECC has established a review procedure that is applied to 

larger transmission projects that may impact the interconnected system. The details of this review procedure are located in 

WECC’s Project Coordination and Path Rating Processes.116 These processes identify potential deliverability issues that may 

result in actions such as the implementation of system protection schemes designed to enhance deliverability and to mitigate 

possible adverse power system conditions. 

The power transfer capabilities of most major subregion transmission interconnections within WECC are limited by system 

stability constraints rather than by thermal limitations. These stability constraints are sensitive to system conditions and may 

often be increased significantly at nominal cost by applying Special Protection Systems (SPS) or Remedial Action Schemes 

 

113 Maintaining Bulk Power System Reliability While Integrating Variable Energy Resources – CAISO Approach.

114 WECC reports feasible transfers, not contracted transfers. This is done to eliminate double counting of resources. This treatment is different from the 

other NERC Assessment Areas.

115 Modeled Transfers: applicable for Assessment Areas that model potential feasible transfers (imports/exports) to eliminate potential double counting of 

capacity. Because of delivery options, the Assessment area does not attempt to align the purchase and sale of contracts. Instead, the assessment area, 

using conservative transfer limits on associated transfer paths, models feasible transfers between areas. Although these transfers are not contracts, Firm 

transmission capacity is held by the importing or exporting entities, and modeling of the existing transmission, including transfer capability, has been 

executed to verify these transfers can occur during the peak season.

116 WECC's Project Coordination and Path Rating Process.
WECC

NERC | 2014 Long-Term Reliability Assessment | November 2014

95

(RAS). In addition, transmission operators may install SPSs or RASs to address localized transmission overloads related to 

single- and multiple-contingency transmission outages. The future use of such relatively inexpensive schemes in lieu of costly 

transmission facility additions—and whether they will be permanent or temporary additions—will depend on as‐yet‐

undetermined system conditions. 

LSEs within WECC are rapidly expanding the use of smart meters and the associated interface equipment. The impacts of such 

facilities relative to power system reliability have not yet been quantified. Area entities are also taking steps to install and 

interface with equipment that may morph into full‐fledged smart grid installations. The pace and extent of such changes is 

presently unknown. CAISO’s website presents its smart grid initiatives, which are typical of activities within the Western 

Interconnection.117

Long-Term Reliability Issues

In 2013 more than 4,700 MW of thermal generation was retired, including 2,250 MW of nuclear generation, 909 MW of coalfired generation, and 1,588 MW of natural-gas-fired generation. However, those retirements were replaced by more than 

9,500 MW of generation additions, including 1,206 MW of wind generation, 3,162 MW of natural-gas-fired generation, and 

3,990 MW of solar generation. WECC continues to track and study the impacts on reliability, as well as other issues, associated 

with the retirement of large thermal generating units in response to higher air emission and water quality standards. 

Associated with the retirement of large coal generating units is the increased demand on natural gas supply and 

transportation as natural gas becomes the primary fuel for new thermal generation. WECC is working with the natural gas 

industry to study potential impacts to reliability as the Western Interconnection becomes more reliant on natural-gas-fired 

generation.

The joint NERC/CAISO study addresses some potential operational impacts from higher levels of variable resources (e.g., 

ancillary services for ramp rates). WECC studies to date have not identified significant issues relative to inertia and frequency 

response, but at some as-yet-unidentified penetration level, inertia and frequency response may become an issue. WECC 

continues to work with entities within the Western Interconnection to identify and study reliability concerns associated with 

the increasing levels of variable and BTMG resources.

 

117 CAISO Smart Grid Roadmap.
NERC | 2014 Long-Term Reliability Assessment | November 2014

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Appendix I: 2014LTRA Reference Case Data Summary

Demand, Resources, and Reserve Margins by Assessment Area: 2015 Summer

Assessment Area / 

Interconnection

Demand (MW) Resources (MW) Reserve Margins (%)

Reference 

Margin Level

Total 

Internal

Net 

Internal Anticipated Prospective

AdjustedPotential Anticipated ProspectiveAdjustedPotential

FRCC 46,719 43,579 55,520 57,311 57,311 27.40% 31.51% 31.51% 15.00%

MISO 128,571 123,828 144,893 150,055 150,258 17.01% 21.18% 21.34% 14.80%

MRO-Manitoba Hydro 3,434 3,193 4,552 4,815 4,815 42.57% 50.79% 50.79% 12.00%

MRO-MAPP 5,028 4,932 6,379 6,379 6,379 29.35% 29.35% 29.35% 15.00%

MRO-SaskPower 3,208 3,122 3,750 3,750 3,750 20.12% 20.12% 20.12% 11.00%

NPCC-Maritimes 3,420 3,087 5,808 5,952 5,952 88.17% 92.84% 92.84% 20.00%

NPCC-New England 26,930 25,763 31,880 31,887 31,887 23.75% 23.77% 23.77% 15.70%

NPCC-New York 34,066 32,877 38,311 41,715 41,715 16.53% 26.88% 26.88% 15.00%

NPCC-Ontario 22,726 22,158 27,112 27,112 27,112 22.36% 22.36% 22.36% 19.50%

NPCC-Québec 21,436 21,436 31,517 30,621 30,621 47.03% 42.85% 42.85% 15.00%

PJM 160,259 145,447 183,163 186,787 186,787 25.93% 28.42% 28.42% 15.70%

SERC-E 44,086 42,329 50,475 53,773 53,773 19.24% 27.04% 27.04% 15.00%

SERC-N 42,100 39,983 50,585 52,478 52,478 26.52% 31.25% 31.25% 15.00%

SERC-SE 47,116 44,950 60,035 60,331 60,333 33.56% 34.22% 34.22% 15.00%

SPP 49,710 48,426 65,942 66,241 66,426 36.17% 36.79% 37.17% 13.60%

TRE-ERCOT 69,057 67,140 76,751 79,574 79,574 14.31% 18.52% 18.52% 13.75%

WECC-CAMX 57,606 55,610 64,102 64,126 64,126 15.27% 15.31% 15.31% 15.02%

WECC-NWPP 66,283 65,467 79,724 80,084 80,113 21.78% 22.33% 22.37% 15.50%

WECC-RMRG 9,899 9,342 15,106 15,106 15,106 61.70% 61.71% 61.71% 13.20%

WECC-SWSG 22,635 22,217 29,289 29,413 29,473 31.83% 32.39% 32.66% 14.06%

Eastern Interconnection 617,372 583,673 728,404 748,586 748,977 24.80% 28.25% 28.32% -

Québec Interconnection 21,436 21,436 31,517 30,621 30,621 47.03% 42.85% 42.85% 15.00%

ERCOT Interconnection 69,057 67,140 76,751 79,574 79,574 14.31% 18.52% 18.52% 13.75%

Western Interconnection 156,423 152,636 188,221 188,730 188,819 23.31% 23.65% 23.71% -

TOTAL-NERC 864,288 824,885 1,024,892 1,047,511 1,047,991 24.25% 26.99% 27.05% -

Demand, Resources, and Reserve Margins by Assessment Area: 2015 Winter

Assessment Area / 

Interconnection

Demand (MW) Resources (MW) Reserve Margins (%)

Reference Margin 

Level

Total 

Internal

Net 

Internal Anticipated Prospective

AdjustedPotential Anticipated ProspectiveAdjustedPotential

FRCC 45,668 42,668 58,546 60,670 60,670 37.21% 42.19% 42.19% 15.00%

MISO 104,414 99,671 139,972 145,134 145,337 40.43% 45.61% 45.82% 14.80%

MRO-Manitoba Hydro 4,652 4,409 5,637 5,901 5,901 27.85% 33.83% 33.83% 12.00%

MRO-MAPP 5,457 5,071 7,163 7,193 7,193 41.26% 41.85% 41.85% 15.00%

MRO-SaskPower 3,557 3,471 4,309 4,309 4,309 24.15% 24.15% 24.15% 11.00%

NPCC-Maritimes 5,477 5,230 6,676 6,820 6,820 27.66% 30.42% 30.42% 20.00%

NPCC-New England 22,755 19,963 34,624 34,993 34,993 73.44% 75.29% 75.29% 15.70%

NPCC-New York 24,795 23,952 39,584 44,026 44,026 65.26% 83.81% 83.81% 15.00%

NPCC-Ontario 21,901 21,172 29,420 29,420 29,420 38.95% 38.95% 38.95% 19.50%

NPCC-Québec 38,316 36,608 41,257 41,257 41,257 12.70% 12.70% 12.70% 11.60%

PJM 135,526 135,526 183,163 188,772 188,772 35.15% 39.29% 39.29% 15.70%

SERC-E 42,466 41,449 55,111 56,676 56,676 32.96% 36.74% 36.74% 15.00%

SERC-N 40,288 38,312 55,418 57,392 57,392 44.65% 49.80% 49.80% 15.00%

SERC-SE 44,692 44,634 60,637 60,982 60,984 35.85% 36.63% 36.63% 15.00%

SPP 36,702 35,642 65,224 65,631 65,817 83.00% 84.14% 84.66% 13.60%

TRE-ERCOT 53,719 52,057 78,277 82,765 82,767 50.37% 58.99% 58.99% 13.75%

WECC-CAMX 40,189 39,203 51,919 52,772 52,772 32.44% 34.61% 34.61% 11.00%

WECC-NWPP 70,778 70,453 82,304 83,217 83,246 16.82% 18.12% 18.16% 16.75%

WECC-RMRG 10,061 9,717 13,995 13,995 13,995 44.03% 44.03% 44.03% 14.98%

WECC-SWSG 15,650 15,314 30,572 30,735 30,848 99.63% 100.70% 101.44% 14.99%

Eastern Interconnection 538,350 521,171 745,485 767,920 768,312 43.04% 47.35% 47.42% -

Québec Interconnection 38,316 36,608 41,257 41,257 41,257 12.70% 12.70% 12.70% 11.60%

ERCOT Interconnection 53,719 52,057 78,277 82,765 82,767 50.37% 58.99% 58.99% 13.75%

Western Interconnection 136,678 134,687 178,790 180,720 180,861 32.74% 34.18% 34.28% -

TOTAL-NERC 767,063 744,522 1,043,808 1,072,662 1,073,197 40.20% 44.07% 44.15% -
Appendix I: 2014LTRA Reference Case Data Summary

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Demand, Resources, and Reserve Margins by Assessment Area: 2019 Summer

Assessment Area / 

Interconnection

Demand (MW) Resources (MW) Reserve Margins

Reference 

Margin Level

Total 

Internal

Net 

Internal Anticipated Prospective

AdjustedPotential Anticipated ProspectiveAdjustedPotential

FRCC 49,852 46,479 57,312 59,874 59,874 23.31% 28.82% 28.82% 15.00%

MISO 133,470 128,679 142,852 151,121 151,917 11.01% 17.44% 18.06% 14.80%

MRO-Manitoba Hydro 3,482 3,238 4,549 4,786 4,786 40.47% 47.80% 47.80% 12.00%

MRO-MAPP 5,810 5,712 6,599 6,599 6,599 15.52% 15.52% 15.52% 15.00%

MRO-SaskPower 3,569 3,483 4,330 4,330 4,330 24.33% 24.33% 24.33% 11.00%

NPCC-Maritimes 3,455 3,114 5,659 5,956 5,956 81.73% 91.27% 91.27% 20.00%

NPCC-New England 27,782 26,788 31,529 32,463 32,463 17.70% 21.18% 21.18% 14.30%

NPCC-New York 35,454 34,265 37,985 43,228 43,228 10.86% 26.16% 26.16% 15.00%

NPCC-Ontario 22,272 21,576 26,630 26,630 26,630 23.42% 23.42% 23.42% 20.00%

NPCC-Québec 21,471 21,471 33,311 32,415 32,415 55.15% 50.97% 50.97% 15.00%

PJM 166,900 154,498 185,928 194,767 194,767 20.34% 26.06% 26.06% 15.70%

SERC-E 46,669 44,735 52,363 55,661 55,918 17.05% 24.42% 25.00% 15.00%

SERC-N 43,677 41,122 49,471 53,071 53,137 20.30% 29.06% 29.22% 15.00%

SERC-SE 50,124 47,909 62,978 63,274 63,540 31.45% 32.07% 32.63% 15.00%

SPP 52,849 51,523 65,394 65,951 66,366 26.92% 28.00% 28.81% 13.60%

TRE-ERCOT 72,859 70,942 78,760 84,972 85,251 11.02% 19.78% 20.17% 13.75%

WECC-CAMX 57,580 55,448 64,014 67,431 67,478 15.45% 21.61% 21.70% 15.02%

WECC-NWPP 71,799 70,973 82,492 84,361 84,774 16.23% 18.86% 19.45% 15.50%

WECC-RMRG 10,558 9,966 15,249 15,292 15,292 53.01% 53.44% 53.44% 13.20%

WECC-SWSG 24,335 23,958 28,991 29,258 29,443 21.01% 22.12% 22.89% 14.06%

Eastern Interconnection 645,365 613,122 733,577 767,711 769,510 19.65% 25.21% 25.51% -

Québec Interconnection 21,471 21,471 33,311 32,415 32,415 55.15% 50.97% 50.97% 15.00%

ERCOT Interconnection 72,859 70,942 78,760 84,972 85,251 11.02% 19.78% 20.17% 13.75%

Western Interconnection 164,272 160,345 190,746 196,342 196,988 18.96% 22.45% 22.85%

TOTAL-NERC 903,967 865,880 1,036,394 1,081,441 1,084,163 19.69% 24.90% 25.21% -

Demand, Resources, and Reserve Margins by Assessment Area: 2019 Winter

Assessment Area / 

Interconnection

Demand (MW) Resources (MW) Reserve Margins

Reference 

Margin Level

Total 

Internal

Net 

Internal Anticipated Prospective

AdjustedPotential Anticipated ProspectiveAdjustedPotential

FRCC 48,241 45,051 61,517 64,244 64,244 36.55% 42.60% 42.60% 15.00%

MISO 110,457 105,667 139,590 147,859 148,655 32.10% 39.93% 40.68% 14.80%

MRO-Manitoba Hydro 4,761 4,517 5,847 6,111 6,111 29.44% 35.28% 35.28% 12.00%

MRO-MAPP 6,311 5,911 7,079 7,079 7,079 19.76% 19.76% 19.76% 15.00%

MRO-SaskPower 3,957 3,871 4,737 4,737 4,737 22.36% 22.36% 22.36% 11.00%

NPCC-Maritimes 5,466 5,214 6,527 6,824 6,824 25.18% 30.88% 30.88% 20.00%

NPCC-New England 21,062 20,084 34,015 34,948 34,948 69.36% 74.01% 74.01% 14.30%

NPCC-New York 25,104 24,261 39,280 44,688 44,688 61.91% 84.20% 84.20% 15.00%

NPCC-Ontario 21,578 20,722 28,392 28,392 28,392 37.01% 37.01% 37.01% 20.00%

NPCC-Québec 39,567 37,565 43,637 43,637 43,637 16.16% 16.16% 16.16% 12.10%

PJM 139,975 139,975 185,928 194,768 194,768 32.83% 39.14% 39.14% 15.70%

SERC-E 44,186 43,102 56,881 58,446 58,716 31.97% 35.60% 36.22% 15.00%

SERC-N 41,955 39,428 53,054 56,844 56,911 34.56% 44.17% 44.34% 15.00%

SERC-SE 46,997 46,934 63,867 64,212 64,492 36.08% 36.81% 37.41% 15.00%

SPP 39,546 38,493 64,484 65,171 65,586 67.52% 69.30% 70.38% 13.60%

TRE-ERCOT 56,281 54,619 79,527 85,777 86,055 45.61% 57.05% 57.56% 13.75%

WECC-CAMX 40,636 39,520 49,913 53,177 53,216 26.30% 34.56% 34.66% 11.00%

WECC-NWPP 75,490 75,165 87,910 89,660 90,106 16.96% 19.28% 19.88% 16.75%

WECC-RMRG 10,584 10,241 13,265 13,306 13,306 29.53% 29.93% 29.93% 14.98%

WECC-SWSG 16,852 16,506 27,398 27,679 27,862 65.99% 67.69% 68.80% 14.99%

Eastern Interconnection 559,596 543,230 751,198 784,321 786,148 38.28% 44.38% 44.72% -

Québec Interconnection 39,567 37,565 43,637 43,637 43,637 16.16% 16.16% 16.16% 12.10%

ERCOT Interconnection 56,281 54,619 79,527 85,777 86,055 45.61% 57.05% 57.56% 13.75%

Western Interconnection 143,562 141,432 178,486 183,822 184,490 26.20% 29.97% 30.44% -

TOTAL-NERC 799,005 776,845 1,052,848 1,097,557 1,100,331 35.53% 41.28% 41.64% -
Appendix I: 2014LTRA Reference Case Data Summary

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Demand, Resources, and Reserve Margins by Assessment Area: 2024 Summer

Assessment Area / 

Interconnection

Demand (MW) Resources (MW) Reserve Margins

Reference 

Margin Level

Total 

Internal

Net 

Internal Anticipated Prospective

AdjustedPotential Anticipated ProspectiveAdjustedPotential

FRCC 52,981 49,458 60,794 63,988 63,988 22.92% 29.38% 29.38% 15.00%

MISO 138,433 133,582 139,521 153,178 154,317 4.45% 14.67% 15.52% 14.80%

MRO-Manitoba Hydro 3,753 3,509 5,242 5,029 5,029 49.38% 43.32% 43.32% 12.00%

MRO-MAPP 6,427 6,319 6,661 6,661 6,661 5.41% 5.41% 5.41% 15.00%

MRO-SaskPower 3,735 3,649 4,349 4,349 4,349 19.21% 19.21% 19.21% 11.00%

NPCC-Maritimes 3,421 3,080 5,659 5,956 5,956 83.75% 93.39% 93.39% 20.00%

NPCC-New England 28,430 27,436 31,529 32,463 32,463 14.92% 18.32% 18.32% 14.30%

NPCC-New York 36,580 35,391 37,985 43,228 43,228 7.33% 22.14% 22.14% 15.00%

NPCC-Ontario 22,541 21,046 27,232 27,232 27,232 29.39% 29.39% 29.39% 20.00%

NPCC-Québec 22,557 22,557 33,770 32,874 32,874 49.71% 45.74% 45.74% 15.00%

PJM 173,729 161,327 187,498 196,338 196,338 16.22% 21.70% 21.70% 15.70%

SERC-E 49,943 47,937 52,702 56,000 56,577 9.94% 16.82% 18.02% 15.00%

SERC-N 45,797 42,692 48,547 53,078 53,222 13.71% 24.33% 24.67% 15.00%

SERC-SE 53,844 51,592 63,068 63,364 63,630 22.24% 22.82% 23.33% 15.00%

SPP 56,991 55,663 63,634 64,299 64,877 14.32% 15.51% 16.55% 13.60%

TRE-ERCOT 77,471 75,554 79,060 87,126 87,404 4.64% 15.32% 15.68% 13.75%

WECC-CAMX 58,930 56,541 64,106 68,285 68,387 13.38% 20.77% 20.95% 15.02%

WECC-NWPP 76,652 75,831 85,828 87,838 88,513 13.18% 15.83% 16.73% 15.50%

WECC-RMRG 11,249 10,616 12,028 12,070 12,073 13.30% 13.70% 13.73% 13.20%

WECC-SWSG 26,709 26,326 29,536 30,066 30,448 12.19% 14.21% 15.66% 14.06%

Eastern Interconnection 676,604 642,680 734,419 775,163 777,866 14.27% 20.61% 21.03% -

Québec Interconnection 22,557 22,557 33,770 32,874 32,874 49.71% 45.74% 45.74% 15.00%

ERCOT Interconnection 77,471 75,554 79,060 87,126 87,404 4.64% 15.32% 15.68% 13.75%

Western Interconnection 173,540 169,314 191,497 198,259 199,422 13.10% 17.10% 17.78%

TOTAL-NERC 950,171 910,105 1,038,746 1,093,421 1,097,566 14.13% 20.14% 20.60% -

Demand, Resources, and Reserve Margins by Assessment Area: 2024 Winter

Assessment Area / 

Interconnection

Demand (MW) Resources (MW) Reserve Margins

Reference 

Margin Level

Total 

Internal

Net 

Internal Anticipated Prospective

AdjustedPotential Anticipated ProspectiveAdjustedPotential

FRCC 50,584 47,295 65,420 68,866 68,866 38.32% 45.61% 45.61% 15.00%

MISO 115,031 110,180 136,310 149,967 151,106 23.72% 36.11% 37.14% 14.80%

MRO-Manitoba Hydro 5,136 4,892 6,365 6,179 6,179 30.11% 26.30% 26.30% 12.00%

MRO-MAPP 7,009 6,584 7,106 7,106 7,106 7.94% 7.94% 7.94% 15.00%

MRO-SaskPower 4,141 4,055 4,829 4,829 4,829 19.08% 19.08% 19.08% 11.00%

NPCC-Maritimes 5,427 5,176 6,527 6,824 6,824 26.11% 31.85% 31.85% 20.00%

NPCC-New England 20,790 19,812 34,015 34,015 34,015 71.69% 71.69% 71.69% 14.30%

NPCC-New York 25,537 24,694 39,280 42,566 42,566 59.07% 72.37% 72.37% 15.00%

NPCC-Ontario 21,628 19,972 29,208 29,208 29,208 46.25% 46.25% 46.25% 20.00%

NPCC-Québec 41,373 39,121 44,121 44,121 44,121 12.78% 12.78% 12.78% 12.10%

PJM 144,913 144,913 187,498 193,012 193,012 29.39% 33.19% 33.19% 15.70%

SERC-E 47,557 46,451 56,827 58,392 58,993 22.34% 25.71% 27.00% 15.00%

SERC-N 44,263 41,021 53,102 57,851 58,006 29.45% 41.03% 41.41% 15.00%

SERC-SE 50,399 50,331 66,238 66,583 66,863 31.61% 32.29% 32.85% 15.00%

SPP 42,064 41,011 62,956 63,146 63,724 53.51% 53.97% 55.38% 13.60%

TRE-ERCOT 60,480 58,818 79,827 83,013 83,292 35.72% 41.14% 41.61% 13.75%

WECC-CAMX 41,564 40,198 51,820 51,820 51,914 28.91% 28.91% 29.15% 11.00%

WECC-NWPP 79,912 79,587 93,002 93,002 93,661 16.86% 16.86% 17.68% 16.75%

WECC-RMRG 11,251 10,905 14,800 14,800 14,803 35.72% 35.72% 35.74% 14.98%

WECC-SWSG 18,439 18,090 28,329 28,329 28,697 56.60% 56.60% 58.63% 14.99%

Eastern Interconnection 584,478 566,387 755,681 788,543 791,296 33.42% 39.22% 39.71% -

Québec Interconnection 41,373 39,121 44,121 44,121 44,121 12.78% 12.78% 12.78% 12.10%

ERCOT Interconnection 60,480 58,818 79,827 83,013 83,292 35.72% 41.14% 41.61% 13.75%

Western Interconnection 151,166 148,780 187,950 187,950 189,074 26.33% 26.33% 27.08% -

TOTAL-NERC 837,497 813,105 1,067,580 1,103,628 1,107,783 31.30% 35.73% 36.24% -
Appendix I: 2014LTRA Reference Case Data Summary

NERC | 2014 Long-Term Reliability Assessment | November 2014

99

Projected Total Internal Demand by Assessment Area and Interconnection: 2015–2024 Summer

Assessment Area / 

Interconnection 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

10-Year 

CAGR

FRCC 46,719 47,615 48,501 49,147 49,852 50,554 51,263 52,049 52,981 52,981 1.41%

MISO 128,571 130,101 131,242 132,376 133,470 134,509 135,526 136,460 137,377 138,433 0.82%

MRO-Manitoba Hydro 3,434 3,483 3,424 3,446 3,482 3,555 3,610 3,655 3,703 3,753 0.99%

MRO-MAPP 5,028 5,374 5,500 5,690 5,810 5,927 6,038 6,145 6,257 6,427 2.77%

MRO-SaskPower 3,208 3,289 3,357 3,469 3,569 3,593 3,634 3,677 3,712 3,735 1.70%

NPCC-Maritimes 3,420 3,529 3,497 3,481 3,455 3,444 3,425 3,421 3,418 3,421 0.00%

NPCC-New England 26,930 27,291 27,521 27,677 27,782 27,911 28,028 28,167 28,298 28,430 0.60%

NPCC-New York 34,066 34,412 34,766 35,111 35,454 35,656 35,890 36,127 36,369 36,580 0.79%

NPCC-Ontario 22,726 22,535 22,344 22,301 22,272 22,170 22,479 22,609 22,616 22,541 -0.09%

NPCC-Québec 21,436 21,196 21,320 21,335 21,471 21,673 22,110 22,274 22,421 22,557 0.57%

PJM 160,259 162,470 164,195 165,479 166,900 168,593 170,027 171,217 172,542 173,729 0.90%

SERC-E 44,086 44,768 45,398 45,992 46,669 47,289 47,928 48,579 49,251 49,943 1.40%

SERC-N 42,100 42,571 42,917 43,298 43,677 44,018 44,470 44,908 45,359 45,797 0.94%

SERC-SE 47,116 48,137 48,931 49,427 50,124 51,135 51,563 52,292 53,046 53,844 1.49%

SPP 49,710 50,993 51,700 52,267 52,849 53,454 53,999 54,817 55,438 56,991 1.53%

TRE-ERCOT 69,057 70,014 70,871 71,806 72,859 73,784 74,710 75,631 76,550 77,471 1.29%

WECC-CAMX 57,606 56,767 57,004 57,245 57,580 58,003 58,257 58,542 58,742 58,930 0.25%

WECC-NWPP 66,283 67,733 69,233 70,674 71,799 72,745 73,586 74,390 75,364 76,652 1.63%

WECC-RMRG 9,899 10,100 10,239 10,410 10,558 10,709 10,843 10,901 11,046 11,249 1.43%

WECC-SWSG 22,635 22,760 23,282 23,762 24,335 24,707 25,113 25,694 26,193 26,709 1.86%

Eastern Interconnection 617,372 626,567 633,293 639,161 645,365 651,809 657,879 664,123 670,366 676,604 1.02%

Québec Interconnection 21,436 21,196 21,320 21,335 21,471 21,673 22,110 22,274 22,421 22,557 0.57%

ERCOT Interconnection 69,057 70,014 70,871 71,806 72,859 73,784 74,710 75,631 76,550 77,471 1.29%

Western Interconnection 156,423 157,360 159,758 162,092 164,272 166,165 167,798 169,527 171,345 173,540 1.16%

TOTAL-NERC 864,288 875,137 885,242 894,393 903,967 913,430 922,497 931,555 940,682 950,171 1.06%

Projected Total Internal Demand by Assessment Area and Interconnection: 2015–2024 Winter

Assessment Area / 

Interconnection 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

10-Year 

CAGR

FRCC 45,668 46,415 47,165 47,692 48,241 48,769 49,323 49,934 50,584 50,584 1.14%

MISO 104,414 107,352 108,414 109,506 110,457 111,360 112,219 113,053 113,797 115,031 1.08%

MRO-Manitoba Hydro 4,652 4,713 4,663 4,705 4,761 4,854 4,931 4,997 5,066 5,136 1.11%

MRO-MAPP 5,457 5,818 5,949 6,176 6,311 6,440 6,572 6,702 6,832 7,009 2.82%

MRO-SaskPower 3,557 3,647 3,722 3,846 3,957 3,984 4,029 4,077 4,116 4,141 1.70%

NPCC-Maritimes 5,477 5,513 5,508 5,493 5,466 5,434 5,421 5,420 5,425 5,427 -0.10%

NPCC-New England 22,755 21,274 21,238 21,153 21,062 20,986 20,918 20,865 20,822 20,790 -1.00%

NPCC-New York 24,795 24,856 24,906 24,966 25,104 25,177 25,252 25,334 25,427 25,537 0.33%

NPCC-Ontario 21,901 21,901 21,529 21,592 21,578 21,535 21,646 21,541 21,508 21,628 -0.14%

NPCC-Québec 38,316 38,612 38,847 39,168 39,567 40,218 40,558 40,862 41,120 41,373 0.86%

PJM 135,526 137,308 138,314 139,213 139,975 141,369 142,489 143,481 144,359 144,913 0.75%

SERC-E 42,466 42,560 42,907 43,476 44,186 44,858 45,603 46,300 46,847 47,557 1.27%

SERC-N 40,288 41,022 41,348 41,639 41,955 42,419 42,902 43,322 43,642 44,263 1.05%

SERC-SE 44,692 45,292 45,946 46,332 46,997 47,635 48,300 48,996 49,679 50,399 1.34%

SPP 36,702 38,123 38,549 39,181 39,546 40,062 40,664 41,141 41,639 42,064 1.53%

TRE-ERCOT 53,719 53,719 54,579 55,441 56,281 57,116 57,962 58,804 59,643 60,480 1.33%

WECC-CAMX 40,189 40,227 40,292 40,432 40,636 40,946 41,209 41,424 41,515 41,564 0.37%

WECC-NWPP 70,778 71,786 73,217 74,430 75,490 76,482 77,422 78,320 79,189 79,912 1.36%

WECC-RMRG 10,061 10,205 10,355 10,466 10,584 10,724 10,863 10,994 11,121 11,251 1.25%

WECC-SWSG 15,650 15,862 16,138 16,443 16,852 17,190 17,492 17,814 18,156 18,439 1.84%

Eastern Interconnection 538,350 545,794 550,157 554,970 559,596 564,883 570,270 575,163 579,742 584,478 0.92%

Québec Interconnection 38,316 38,612 38,847 39,168 39,567 40,218 40,558 40,862 41,120 41,373 0.86%

ERCOT Interconnection 53,719 53,719 54,579 55,441 56,281 57,116 57,962 58,804 59,643 60,480 1.33%

Western Interconnection 136,678 138,080 140,002 141,771 143,562 145,341 146,986 148,551 149,981 151,166 1.13%

TOTAL-NERC 767,063 776,205 783,586 791,350 799,005 807,558 815,776 823,381 830,486 837,497 0.98%
Appendix I: 2014LTRA Reference Case Data Summary

NERC | 2014 Long-Term Reliability Assessment | November 2014

100

Projected Transmission Additions by Assessment Area and Interconnection: 2014–2024

Assessment Area/

Interconnection

Under 

Construction 10-Year Planned 10-Year Conceptual

FRCC 67 513 20 

MISO 1,489 4,525 0 

MRO-Manitoba Hydro 1,908 301 0 

MRO-MAPP 379 201 102 

MRO-SaskPower 0 663 220 

NPCC-Maritimes 0 201 50 

NPCC-New England 234 164 261 

NPCC-New York 0 1,217 343 

NPCC-Ontario 0 0 240 

NPCC-Québec 266 689 199 

PJM 740 1,694 584 

SERC-E 421 139 0 

SERC-N 45 202 190 

SERC-SE 175 434 12 

SPP 1,171 2,006 176 

TRE-ERCOT 85 682 426 

WECC-CAMX 288 652 1,307 

WECC-NWPP 12 4,652 1,343 

WECC-RMRG 2 562 1,169 

WECC-SRSG 172 1,125 719 

EASTERN INTERCONNECTION 6,629 12,260 2,198 

QUÉBEC INTERCONNECTION 266 689 199 

TEXAS INTERCONNECTION 85 682 426 

WESTERN INTERCONNECTION 475 6,992 4,538 

TOTAL-NERC 7,454 20,622 7,360 
Appendix II: Reliability Assessment Definitions

NERC | 2014 Long-Term Reliability Assessment | November 2014

101

Appendix II: Reliability Assessment Glossary

Term Definition

Ancillary Services

Those services that are necessary to support the transmission of capacity and energy from resources to loads 

while maintaining reliable operation of the Transmission Service Provider's transmission system in accordance 

with good utility practice (Source: NERC Glossary of Terms)

Anticipated Resources Includes Existing-Certain Capacity, Net Firm Transfers (Imports – Exports), and Tier 1 Capacity Additions.

Anticipated Reserve 

Margin Anticipated Resources minus Net Internal Demand, divided by Net Internal Demand, shown as a percentile.

Assessment Area

Based on existing ISO/RTO footprints; otherwise, based on individual Planning Coordinator or group of Planning 

Coordinators. NERC collects data for seasonal and long-term assessments based on these footprints that align 

with how the system is planned and operated.

Balancing Authority

The responsible entity that integrates resource plans ahead of time, maintains load-interchange-generation 

balance within a Balancing Authority Area, and supports Interconnection frequency in real time. (Source: NERC 

Glossary of Terms)

Bulk Electric System See NERC Glossary of Terms

Bulk-Power System

A) facilities and control systems necessary for operating an interconnected electric energy transmission network 

(or any portion thereof); and (B) electric energy from generation facilities needed to maintain transmission 

system reliability. The term does not include facilities used in the local distribution of electric energy. (Source: 

NERC Glossary of Terms)

Capacity Transfers 

(Transactions)

There are three types of capacity transfers (transactions):

Firm: “Firm” transfers that require the execution of a contract that is in effect during the projected peak. The net 

of all Firm transfers (imports minus exports) are applied towards Anticipated Resources. 

Modeled: transfers that are applicable for Assessment Areas that model potential feasible transfers 

(imports/exports). While these transfers do not have Firm contracts, modeling of the existing transmission, 

including transfer capability, has been executed to verify these transfers can occur during the peak season. The 

net of all Modeled transfers (imports minus exports) are applied towards Anticipated Resources.

Expected: transfers without the execution of a Firm contract, but with a high expectation that a Firm contract will 

be executed in the future and will be in effect during the projected peak. The net of all Modeled transfers 

(imports minus exports) are applied towards Prospective Resources.

Conservation (Energy 

Conservation)

A reduction in energy consumption that corresponds with a reduction in service demand. Service demand can 

include buildings-sector end uses such as lighting, refrigeration, and heating; industrial processes; or vehicle 

transportation. Unlike energy efficiency, which is typically a technological measure, conservation is better 

associated with behavior. Examples of conservation include adjusting the thermostat to reduce the output of a 

heating unit, using occupancy sensors that turn off lights or appliances, and car-pooling. (Source: DOE-EIA)

Critical Peak-Pricing 

(CPP) with Load Control

Price structure designed to encourage reduced consumption during periods of high wholesale market prices or 

system contingencies by imposing a pre-specified high rate or price for a limited number of days or hours. Critical 

Peak Pricing (CPP) with Direct Load Control combines Direct Load Control with a pre-specified high price for use 

during designated critical peak periods triggered by system contingencies or high wholesale market prices. Subset 

of Controllable and Dispatchable Demand Response.

Dispatchable and Controllable Demand-Side Management that combines direct remote control with a prespecified high price for use during designated critical peak periods, triggered by system contingencies or high 

wholesale market prices.

Curtailment A reduction in the scheduled capacity or energy delivery of an Interchange Transaction. (Source: NERC Glossary of 

Terms)

Demand

1. The rate at which electric energy is delivered to or by a system or part of a system, generally expressed in 

kilowatts or megawatts, at a given instant or averaged over any designated interval of time.

2. The rate at which energy is being used by the customer.

Demand Response

Changes in electric use by Demand-Side resources from normal consumption patterns in response to changes in 

the price of electricity, or to incentive payments designed to induce lower electricity use at times of high 

wholesale market prices, or when required to maintain system reliability. Demand Response can be counted in 

resource adequacy studies either as a load-modifier, or as a resource.

Controllable and Dispatchable Demand Response requires the System Operator to have physical command of the 

resources (Controllable) or be able to activate it based on instruction from a control center. Controllable and 

Dispatchable Demand Response includes four categories: Critical Peak Pricing (CPP) with Load Control; Direct 

Control Load Management (DCLM); Load as a Capacity Resource (LCR); and Interruptible Load (IL).
Appendix II: Reliability Assessment Definitions

NERC | 2014 Long-Term Reliability Assessment | November 2014

102

Demand-Side 

Management

All activities or programs undertaken by any applicable entity to achieve a reduction in Demand. (Source: NERC 

Glossary of Terms)

Derate The amount of capacity that is expected to be unavailable during the seasonal peak.

Designated Network 

Resource

Any designated generating resource owned, purchased or leased by a Network Customer under the Network 

Integration Transmission Service Tariff. Network Resources do not include any resource, or any portion thereof, 

that is committed for sale to third parties or otherwise cannot be called upon to meet the Network Customer's 

Network Load on a non-interruptible basis, except for purposes of fulfilling obligations under a Commissionapproved reserve sharing program. 

Distributed Energy 

Resources (DERs)

Distributed energy resources (DERs) are smaller power sources that can be aggregated to provide power 

necessary to meet regular demand. As the electricity grid continues to modernize, DERs such as storage and 

advanced renewable technologies can help facilitate the transition to a smarter grid. (Source: EPRI)

Distributed Generation See Distributed Energy Resources

Energy Efficiency

Refers to programs that are aimed at reducing the energy used by specific end-use devices and systems, typically 

without affecting the services provided. These programs reduce overall electricity consumption (reported in 

megawatt-hours), often without explicit consideration for the timing of program-induced savings. Such savings 

are generally achieved by substituting technologically more advanced equipment to produce the same level of 

end-use services (e.g. lighting, heating, motor drive) with less electricity. Examples include high-efficiency 

appliances, efficient lighting programs, high-efficiency heating, ventilating and air conditioning (HVAC) systems or 

control modifications, efficient building design, advanced electric motor drives, and heat recovery systems. 

Results in permanent changes to electricity use by replacement of end-use devices with more efficient end-use 

devices or more effective operation of existing devices. Generally, it results in reduced consumption across all 

hours rather than event-driven targeted load reductions. (Source: DOE-EIA)

Estimated Diversity

The electric utility system's load is made up of many individual loads that make demands on the system, with 

peaks occurring at different times throughout the day. The individual loads within the customer classes follow 

similar usage patterns, but these classes of service place different demands upon the facilities and the system 

grid. The service requirements of one electrical system can differ from another by time-of-day usage, facility 

usage, and/or demands placed upon the system grid.

Existing-Certain Capacity

 Included in this category are existing generator units (expressed in MW), or portions of existing generator 

units, that are physically located within the assessment area that meet at least one of the following 

requirements when examining the projected peak for the summer and winter of each year: (1) unit must 

have a Firm capability (defined as the commitment of generation service to a customer under a contractual 

agreement to which the parties to the service anticipate no planned interruption (applies to generation and 

transmission), a Power Purchase Agreement (PPA), and Firm transmission; (2) unit must be classified as a 

Designated Network Resource; (3) where energy-only markets exist, unit must be a designated market 

resource eligible to bid into the market.

Disturbance

An unplanned event that produces an abnormal system condition; any perturbation to the electric system, or the 

unexpected change in ACE that is caused by the sudden failure of generation or interruption of load. (Source: 

NERC Glossary of Terms)

Existing-Other Capacity

Included in this category are existing generator units, or portions of existing generator units, that are physically 

located within the assessment area that do not qualify as Existing-Certain when examining the projected peak for 

the summer and winter of each year. Accordingly, these are the units, or portions of units, may not be available to 

serve peak demand for each season/year.

Energy-Only

Generating resources that are designated as energy-only resources or have elected to be classified as energy-only 

resources and may include generating capacity that can be delivered within the area but may be recallable to 

another area. Designated energy –only resources do not have capacity rights.

Firm (Transmission 

Service)

The highest quality (priority) service offered to customers under a filed rate schedule that anticipates no planned 

interruption. (Source: NERC Glossary of Terms)

Forced Outage

The removal from service availability of a generating unit, transmission line, or other facility for emergency 

reasons. Also, the condition in which the equipment is unavailable due to unanticipated failure. (Source: NERC 

Glossary of Terms)

Frequency Regulation The ability of a Balancing Authority to help the Interconnection maintain Scheduled Frequency. This assistance 

can include both turbine governor response and Automatic Generation Control. (NERC Glossary of Terms)

Frequency Response

Equipment: The ability of a system or elements of the system to react or respond to a change in system

frequency. System: The sum of the change in demand, plus the change in generation, divided by the change in 

frequency, expressed in megawatts per 0.1 Hertz (MW/0.1 Hz). (Source: NERC Glossary of Terms)

Expected (Provisional) 

Capacity Transfers

Future transfers that do not currently have a Firm contract, but there is a reasonable expectation that a Firm

contract will be signed. These transfers are included in the Prospective Resources.

Generator Operator The entity that operates generating unit(s) and performs the functions of supplying energy and Interconnected 

Operations Services. (NERC Glossary of Terms)

Generator Owner Entity that owns and maintains generating units. (NERC Glossary of Terms)
Appendix II: Reliability Assessment Definitions

NERC | 2014 Long-Term Reliability Assessment | November 2014

103

Independent Power 

Producer

Any entity that owns or operates an electricity generating facility that is not included in an electric utility’s rate 

base. This term includes, but is not limited to, cogenerators and small power producers and all other nonutility 

electricity producers, such as exempt wholesale generators, who sell electricity. (NERC Glossary of Terms)

Interconnection When capitalized, any one of the four major electric system networks in North America: Eastern, Western, ERCOT 

and Québec. (NERC Glossary of Terms)

Interruptible Load

or

Interruptible Demand

Demand that the end-use customer makes available to its Load-Serving Entity via contract or agreement for 

curtailment. (NERC Glossary of Terms)

Load An end-use device or customer that receives power from the electric system. (NERC Glossary of Terms)

Load-Serving Entity Secures energy and transmission service (and related Interconnected Operations Services) to serve the electrical 

demand and energy requirements of its end-use customers. (NERC Glossary of Terms)

Net Energy for Load 

(NEL)

The amount of energy required by the reported utility or group of utilities' retail customers in the system's service 

area plus the amount of energy supplied to full and partial requirements utilities (wholesale requirements 

customers) plus the amount of energy losses incurred in the transmission and distribution. (Source: FERC-714)

Net Balancing Authority Area generation, plus energy received from other Balancing Authority Areas, less energy 

delivered to Balancing Authority Areas through interchange. It includes Balancing Authority Area losses but 

excludes energy required for storage at energy storage facilities. (NERC Glossary of Terms)

Net Internal Demand Total Internal Demand reduced by dispatchable and controllable Demand Response. (NERC Glossary of Terms)

Non-Firm Transmission 

Service

Transmission service that is reserved on an as-available basis and is subject to curtailment or interruption. (NERC 

Glossary of Terms)

Non-spinning Reserves

The portion of Operating Reserve consisting of (1) generating reserve not connected to the system but capable of 

serving demand within a specified time; or (2) interruptible load that can be removed from the system in a 

specified time.(NERC Glossary of Terms)

Off-Peak Those hours or other periods defined by NAESB business practices, contract, agreements, or guides as periods of 

lower electrical demand. (NERC Glossary of Terms)

On-Peak Those hours or other periods defined by NAESB business practices, contract, agreements, or guides as periods of 

higher electrical demand. (NERC Glossary of Terms)

Open Access Same Time 

Information Service

An electronic posting system that the Transmission Service Provider maintains for transmission access data and 

that allows all transmission customers to view the data simultaneously. (NERC Glossary of Terms)

Open Access 

Transmission Tariff

Electronic transmission tariff accepted by the U.S. Federal Energy Regulatory Commission requiring the 

Transmission Service Provider to furnish to all shippers with non-discriminating service comparable to that 

provided by Transmission Owners to themselves. (NERC Glossary of Terms)

Operating Reserves The capability above Firm system demand required to provide for regulation, load forecasting error, equipment 

forced and scheduled outages and local area protection. It consists of spinning and non-spinning reserve.

Planning Coordinator 

(Planning Authority)

The responsible entity that coordinates and integrates transmission facility and service plans, resource plans, and 

protection systems. (NERC Glossary of Terms)

Planning Reserve 

Margins

Anticipated Reserve Margin: Anticipated Resources, less Net Internal Demand, divided by Net Internal Demand.

Prospective Reserve Margin: Prospective Resources, less Net Internal Demand, divided by Net Internal Demand.

Adjusted-Potential Reserve Margin: Adjusted-Potential Resources, less Net Internal Demand, divided by Net 

Internal Demand.

Peak Demand The highest hourly integrated Net Energy For Load (or highest instantaneous demand) within a Balancing 

Authority Area occurring within a given period (e.g., day, month, season, or year). (NERC Glossary of Terms)

Power Purchase 

Agreement

Guarantees a market for power produced by an independent power producer and the price at which it is sold to a 

purchaser. Such an agreement imposes legal obligations on both the parties to perform previously accepted tasks 

in a predetermined manner.

Prospective Capacity 

Resources Anticipated Resources plus Existing-Other capacity, plus 50 percent of Tier 2 Capacity, plus net Expected transfers.

Prospective Capacity 

Reserve Margin

Prospective Capacity Resources minus Net Internal Demand shown divided by Net Internal Demand, shown as a 

percentile.

Ramp Rate (Ramp)

Schedule: the rate, expressed in megawatts per minute, at which the interchange schedule is attained during the 

ramp period. Generator: the rate, expressed in megawatts per minute, that a generator changes its output.

(NERC Glossary of Terms)

Rating The operational limits of a transmission system element under a set of specified conditions. (NERC Glossary of 

Terms)

Reactive Power

The portion of electricity that establishes and sustains the electric and magnetic fields of alternating-current 

equipment. Reactive power must be supplied to most types of magnetic equipment, such as motors and 

transformers. It also must supply the reactive losses on transmission facilities. Reactive power is provided by 

generators, synchronous condensers, or electrostatic equipment such as capacitors and directly influences 

electric system voltage. It is usually expressed in kilovars (kvar) or megavars (MVar). (NERC Glossary of Terms)

Real Power The portion of electricity that supplies energy to the load. (NERC Glossary of Terms)
Appendix II: Reliability Assessment Definitions

NERC | 2014 Long-Term Reliability Assessment | November 2014

104

Reference Margin Level

This metric is typically based on the load, generation, and transmission characteristics for each Assessment Area. 

In some cases, it is a requirement implemented by the respective state(s), provincial authority, ISO/RTO, or other 

regulatory body. If such a requirement exists, the respective Assessment Area generally adopts this requirement 

as the Reference Margin Level. In some cases, the Reference Margin Level may fluctuate for each season of the 

assessment period. If a Reference Margin Level is not provided by an Assessment Area, NERC applies a 15 percent 

Reference Margin Level for predominately thermal systems and 10 percent for predominately hydro systems.

Reliability Coordinator

The entity that is the highest level of authority who is responsible for the reliable operation of the Bulk Electric 

System, has the Wide Area view of the Bulk Electric System, and has the operating tools, processes and 

procedures, including the authority to prevent or mitigate emergency operating situations in both next-day 

analysis and real-time operations. The Reliability Coordinator has the purview that is broad enough to enable the 

calculation of Interconnection Reliability Operating Limits, which may be based on the operating parameters of 

transmission systems beyond any Transmission Operator’s vision. (NERC Glossary of Terms)

Renewable Energy 

(Renewables

Energy derived from resources that are regenerative or for all practical purposes cannot be depleted. Types of 

renewable energy resources include moving water (hydro, tidal and wave power), thermal gradients in ocean 

water, biomass, geothermal energy, solar energy, and wind energy. Municipal solid waste (MSW) is also 

considered to be a renewable energy resource. (Source: DOE-EIA)

Reserve Sharing Group

A group whose members consist of two or more Balancing Authorities that collectively maintain, allocate, and 

supply operating reserves required for each Balancing Authority’s use in recovering from contingencies within the 

group. Scheduling energy from an Adjacent Balancing Authority to aid recovery need not constitute reserve 

sharing provided the transaction is ramped in over a period the supplying party could reasonably be expected to 

load generation in (e.g., ten minutes). If the transaction is ramped in quicker (e.g., between zero and ten minutes) 

then, for the purposes of Disturbance Control Performance, the Areas become a Reserve Sharing Group. (Source: 

NERC Glossary of Terms)

Stand-by Load under 

Contract

Demand which is normally served by behind-the-meter generation, which has a contract to provide power if the 

generator becomes unavailable. 

Spinning Reserves Unloaded generation that is synchronized and ready to serve additional demand.(NERC Glossary of Terms)

Time-of-Use (TOU)

Rate and/or price structures with different unit prices for use during different blocks of time.

Time-Sensitive Pricing (Non-dispatchable Demand Response) — Retail rates and/or price structures designed to 

reflect time-varying differences in wholesale electricity costs, and thus provide consumers with an incentive to 

modify consumption behavior during high-cost or peak periods.

Total Internal Demand

Projected sum of the metered (net) outputs of all generators within the system and the metered line flows into 

the system, less the metered line flows out of the system. The demands for station service or auxiliary needs 

(such as fan motors, pump motors, and other equipment essential to the operation of the generating units) are 

not included. Total Internal Demand should be reduced by indirect Demand-Side Management programs such as 

conservation programs, improvements in efficiency of electric energy use, Stand-by Load under Contract, all nondispatchable Demand Response programs (such as Time-of-Use, Critical Peak Pricing, Real Time Pricing and 

System Peak Response Transmission Tariffs). Adjustments for controllable Demand Response should not be 

included in this value.

The demand of a metered system, which includes the Firm demand, plus any Controllable and Dispatchable DSM 

load and the load due to the energy losses incurred within the boundary of the metered system. (Source: NERC 

Glossary of Terms)

Transmission-Limited 

Resources

The amount of transmission-limited generation resources that have deliverability limitations to serve load within 

the Region. If capacity is limited by both studied transmission limitations and generator derates, the generator 

derates takes precedence.

Uncertainty The magnitude and timing of variable generation output is less predictable than for conventional generation.

Variable Energy 

Resources

Resources with output that are highly variable subject to weather fluctuations such as wind speed and cloud 

cover.

Variability The output of variable generation changes according to the availability of the primary fuel (wind, sunlight and 

moving water) resulting in fluctuations in the plant output on all time scales.
Appendix III: 2014 Polar Vortex Scenario Analysis

NERC | 2014 Long-Term Reliability Assessment | November 2014

105

Appendix III: 2014 Polar Vortex Scenario Analysis

Overview

The 2014 polar vortex involved extended periods of extreme cold weather from January 6–8, 2014, in several parts of North 

America, presenting challenges for System Operators in both the Eastern and Texas Interconnections. During the event, the 

BPS was stressed with high periods of demand, establishing new records for several areas. Concurrently, an increased number 

of units experienced forced outages amounting to over 10,000 MW, resulting in the use of emergency operating procedures 

and calling DR programs in several areas. Despite these extreme conditions, the BPS remained stable and generally performed 

reliably throughout the duration of the event, primarily because of preparation efforts prior to the cold snap. Specifically,

generator owners took preemptive steps to prepare equipment for the freezing temperatures. These steps included:

cancelling scheduled generator outages, installing additional insulation, and testing dual-fuel capabilities. Similarly, System 

Operators coordinated with neighboring areas to ensure resource availability and share other pertinent information.

Subsequent to a thorough review of the event, NERC released the Polar Vortex Review report in September 2014, based on 

data and information provided from the NERC Generator Availability Data System (GADS), as well as supplemental support 

from the impacted Assessment Areas. According to these data, it was concluded that forced outages during the event were 

primarily caused by the following:

1. Inoperable equipment in extreme low temperatures,

2. Unavailability of fuel at generating units (due to supply or transportation or a combination of both), and

3. Challenges for some dual-fuel capable units in switching from a primary to a secondary fuel. 

Colder temperatures contributed to higher electricity demand while also increasing the demand for natural gas used for 

residential heating in some parts of North America. These conditions stressed the ability of pipeline operators and suppliers

to deliver natural gas to the power sector, which resulted in a significant amount of gas-fired generation being unavailable 

due to gas curtailments. This was particularly relevant considering that gas-fired units accounted for approximately 40 

percent of the generation mix during the 2014 polar vortex. Accordingly, natural-gas-fired units were also the most impacted 

compared to other generators, representing over 55 percent of all forced outages during the event.

Scenario Assumptions and Results

In addition to the Polar Vortex Review, NERC staff also conducted scenarios for MISO, PJM, SERC-E, and TRE-ERCOT. Each of 

these Assessment Areas experienced high forced outage rates during the event. NERC’s scenario assumptions involved 

applying these actual forced outage rates as derates to existing and projected (Tier 1) capacity data from the 2014LTRA 

reference case. Similarly, projected load was assumed to be consistent with the extreme loads during the event.

Fuel Derates and Net Internal Demand Assumptions (Based on Actual Forced Outages and Demand)

Assessment Area

Applied Derate

Coal Petroleum Natural Gas Nuclear Wind Solar Other Generation Assumed Net Internal Demand

MISO 15% 10% 30% 0% 100% 100% 0% 110%

PJM 30% 10% 20% 20% 100% 100% 0% 105%

SERC-E 0% 0% 0% 0% 100% 100% 0% 118%

TRE-ERCOT 15% 0% 25% 0% 100% 100% 0% 110%
Appendix III: 2014 Polar Vortex Scenario Analysis

NERC | 2014 Long-Term Reliability Assessment | November 2014

106

MISO (Right) and PJM (Left)

SERC-E (Right) and TRE-ERCOT (Left)

Scenario Observations

This analysis demonstrates that a repeated extreme weather event with conditions similar to those observed during the 2014 

polar vortex would result in inadequate Anticipated Resources, based on the 2014LTRA reference case. This highlights the 

need for system planners to more strongly consider generator performance during extreme weather events, particularly for 

natural-gas-fired units.

-10%

0%

10%

20%

30%

40%

50%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Margin Scenario Margin

Reference Margin Level

-10%

0%

10%

20%

30%

40%

50%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Margin Scenario Margin

Reference Margin Level

-5%

5%

15%

25%

35%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Margin Scenario Margin

Reference Margin Level

-10%

0%

10%

20%

30%

40%

50%

60%

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Anticipated Margin Scenario Margin

Reference Margin Level
	






	






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