# Energy Efficiency in Distribution Systems Impact Analysis Approach 

# 11.30.2011Voltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 1 

## Table of Contents 

# 1 Focus Area Overview 

# 2 Technologies and Assets 

# 3 Impact AnalysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 2 Focus Area Overview » Six Focus Areas 

## Six areas are of particular interest for determining smart grid impacts.

Note that AMI can be used to increase the functionality of distribution applications. Peak Demand and Electricity Consumption • Advanced Metering Infrastructure • Pricing Programs and Customer Devices • Direct Load Control 

### Operations and Maintenance Savings from Advanced Metering • Meter Reading • Service changes • Outage management 

### Distribution System Reliability • Feeder switching • Monitoring and health sensors 

### Energy Efficiency in Distribution Systems • Voltage optimization • Conservation voltage reduction • Line losses 

### Operations and Maintenance Savings from Distribution Automation • Automated and remote operations • Operational Efficiency 

### Transmission System Operations and Reliability • Application of synchrophasor technology for wide area monitoring, visualization and controlVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 3 Focus Area Overview » Benefits Framework 

## DOE’s Smart Grid Benefits Framework relates smart grid assets, functions and benefits.
Smart Grid Assets Higher Functionality Benefits for Utilities, Consumers and Society
• Smart meters • Automated switches • Phasor measurement units • Better load measurement and management • Faster circuit switching • Grid disturbance monitoring • Peak load reduction • Shorter outages • Better grid reliabilityVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 4 Focus Area Overview » Voltage and VAR Control 

## Our analysis will try to determine how asset combinations can be used to reduce distribution losses and end - use energy consumption.

• Determine the improvement in energy efficiency from the application of technology used to optimize circuit voltage and implement conservation voltage reduction. • Determine what technology configurations are most important for delivering measurable results. • Quantify the value of energy and capacity savings for utilities, electricity savings for customers, and lower emissions. Analysis ObjectivesVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 5 

## Table of Contents 

# 1 Focus Area Overview 

# 2 Technologies and Assets 

# 3 Impact AnalysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 6 

## Voltage and VAR control technologies monitor power, determine control settings, and then physically adjust voltage and reactive power.

Equipment to change voltage and power factor Technology to measure voltage and power factor, control equipment, and coordinate/optimize settings • Substation voltage and current

sensors (including CTs/VTs) • Distribution voltage and current

sensors (typically included in control packages) • SCADA to communicate readings

back to central location • Smart meters • AMI communications to

communicate readings back to central location • Control packages for transformer load tap changers (LTCs) • Control packages for capacitors • Control packages for voltage

regulators • Distribution management

systems and voltage optimization software • Transformer LTCs • Distribution capacitor banks • Distribution voltage regulators

Capacitor bank Voltage regulator Control package Distribution Management System Line voltage sensor Smart meter Technologies and Assets » Tools for Managing Voltage and Power FactorVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 7 Technologies and Assets » Three General Objectives 

## Utilities are pursuing three general objectives as part of their SGIG projects. Voltage and VAR Control (VVC) Voltage Optimization (VO) Conservation Voltage Reduction (CVR) Operating transformer load tap - changers, line voltage regulators and capacitor banks to adjust voltage along a distribution circuit and compensate load power factor. Coordinating VVC devices to achieve voltage profiles that meet the utility’s operational objectives, including energy delivery efficiency, power quality, and reliability. Utilizing VVC and VO functionality to lower distribution voltages for energy savings, without causing customer voltages to fall below minimum operating limits.Voltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 8 Technologies and Assets » Basic Voltage Regulation with an LTC 

## Line voltage drops from the LTC at the head of the distribution line to customers farther out on the line. S/S 2 3 4 5 6 7 Customer Loads at 1MW each 

### 1 M LTC

126V

114V 120V 127V

110V 7 mile feeder at 12.47 kV Transformer Load Tap Changer ANSI Standard C84.1 - 1995 “A” Service Voltage Range Hypothetical voltage profileVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 9 Technologies and Assets » Coordinated LTC and Voltage Regulator 

## A voltage regulator can boost (raise) or buck (lower) voltage at a point on the distribution line and regulate down - line voltage. S/S 2 3 4 5 6 7 Customer Loads 

### 1 M LTC

126V

114V 120V 127V

110V 

### Reg

Baseline Regulator Regulator + CVR Line Voltage Regulator

The utility can use better voltage control to keep voltage closer to nominal, or lower it for a CVR effect.Voltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 10 Technologies and Assets » Coordinated LTC, Regulator and Capacitor Bank 

## A capacitor bank can help regulation by compensating for the lagging power factor of load and the line itself. S/S 2 3 4 5 6 7 Customer Loads 

### 1 M LTC

126V

114V 120V 127V

110V 

### Reg

Baseline Reg + Cap Reg + Cap + CVR 

### Cap Capacitor Bank

Coordination of multiple control devices can produce a flatter voltage profile, and allow more aggressive CVR.Voltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 11 Technologies and Assets » Projects Deploying Automated Capacitors 

## Over 19,000 capacitor banks are being deployed by 41 projects as part of the SGIG program.

18 17 6 IOU Muni/PPA Cooperative 18,558 542 208
IOU Muni/PPA Cooperative 

### 41 SGIG Projects Expected to Deploy Voltage and VAR Control Functionality Number of Automated Capacitors Expected to be Deployed by Utility Type

Source: SGIG Build metrics and Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 12 

## Projects vary with utility objectives, operational experience, and current system configurations and equipment.

Voltage Optimization Conservation Voltage ReductionImpact Functionality SGIG Projects Voltage and VAR Control 17 Voltage Optimization 11 Voltage Optimization and CVR 13 Total 41
Degree of Functionality Voltage and VAR Control 

### We expect that impact will increase with higher functionality Technologies and Assets » Voltage and VAR Control Functionality

Source: SGIG Proposals, MBRPs Build metrics and Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 13 Technologies and Assets » Circuits with Automated Equipment 

## On average SGIG projects are installing automated equipment on about 25% of the circuits in their service territory.

* Includes projects that are installing automated feeder switches on some or all of the circuits 

### Number of Circuits with Automated Equipment vs. Total Service Territory

Source: SGIG Build metrics and Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 14 Technologies and Assets » Deployment Expected vs. To - Date 

## Nearly 19,000 capacitor banks are being deployed as part of the SGIG program. More than 80% are being deployed by four Investor Owned Utilities.

Source: SGIG Build metrics and Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 15 

## $133 $34 $58 $14 $27 $ - $20 $40 $60 $80 $100 $120 $140

Total Communications Infrastructure* Auto Capacitors Auto Regulators Distribution Management Systems* Technologies and Assets » Investments in VVC Assets 

## As of Q2 2011, recipients had spent approximately $133 million on VVC assets. Installed Costs ($ Millions) of Volt/Var and Supporting Equipment as of 2Q 2011

• Fifty percent of total costs allocated to volt/var. Assumed other costs allocated to reliability initiatives ** Avg. Const / Unit estimates include communication infrastructure Avg. Cost / Unit** Auto Capacitor $ 12,565 Auto Regulator $ 8,781

Source: SGIG Build metrics and Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 16 

## Table of Contents 

# 1 Focus Area Overview 

# 2 Technologies and Assets 

# 3 Impact AnalysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 17 Impact Analysis » Key Metrics 

## Key metrics will be collected from SGIG and SGD projects for use in analyzing Voltage and VAR Control with smart grid.

• Automated capacitors • Automated regulators • Distribution circuit monitors or SCADA • Distribution Management Systems (DMS) • DMS integration with Advanced Metering Infrastructure • Others • CVR algorithms • Load balancing • Reconductoring Key Build Metrics (Technologies) • Distribution feeder load (hourly and/or average) • Distribution power factor (hourly and/or average) • Distribution losses (average/peak, % of load, or MWh for reporting period) • Emissions reductions from energy savings • Others • Energy savings from CVR Key Impact MetricsVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 18 Impact Analysis » Lower Losses › Benefits Logic 

## Analyzing the change in hourly circuit load can contribute to determining how much energy is saved by reducing distribution losses.

Energy Savings

from Lower Losses Hourly Circuit Load Data (MW, MVAR) Determine Change in

Losses Determine Change in Distribution Circuit Load
Impact Metric Benefit Value of energy savings for

utilities Value of lower emissions for society
AnalysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 19 Impact Analysis » Lower Losses › Hourly Circuit Load Data 

## Many projects are reporting hourly circuit data for real and reactive power, and this data can be used to determine other parameters.

0 1000 2000 3000 4000 5000 6000 7000

P (kW) Q (kVAR) Time P (kW) Q (kVAR) 1:00 AM 4298 1949 2:00 AM 4061 1542 3:00 AM 3284 1574 4:00 AM 3408 1277 5:00 AM 2896 1519 6:00 AM 2900 1200 7:00 AM 3185 1388 8:00 AM 3103 1476 9:00 AM 4006 1868 10:00 AM 3817 1884 11:00 AM 4351 1997 12:00 PM 4635 2323

1:00 PM 5129 2390 2:00 PM 5213 2673 3:00 PM 5517 2677 4:00 PM 5378 2478 5:00 PM 5400 2855 6:00 PM 5658 2986 7:00 PM 5720 2638 8:00 PM 5643 2922 9:00 PM 5290 2664 10:00 PM 5346 2628 11:00 PM 5019 2496 12:00 AM 4801 2667 

### Real and reactive power for a day Hourly Circuit Load Data (MW, MVAR) Determine Change in Distribution Circuit Load

Source: Illustrative results from Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 20 Impact Analysis » Lower Losses › The Meaning of Line Losses 

## Energy is wasted as electricity flows through distribution lines. This wasted energy is known as “line losses”.

Conductor ( Resistance, R L ) 

### Modern overhead distribution conductor is typically made of stranded aluminum wire, sometimes with a steel reinforcing core. The resistance ( R L 

### ) of the conductor is about 0.3 ohms per mile, and decreases with cross sectional area. As line current flows through the conductor, its resistance dissipates power in the form of “line losses”. IL = Line Current 

# watts 2 L L losses line 

# R I P **=** Higher line current means higher line losses, and vice versa Energy Savings

from Lower Losses Determine Change in

LossesVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 21 Impact Analysis » Lower Losses › Calculation of Energy Savings from P/Q Data 

## Hourly data for real and reactive power will determine hourly line losses, and the difference between baseline and impact losses yields energy savings. Some projects will be reporting hourly circuit load data for real (P) and reactive (Q) power. Using this information we will calculate hourly values for apparent power (S3 θ

### ) and power factor, and then calculate hourly line current ( IL 

### ): S = Apparent Power (VA)

P = Real Power (W) θ = Phase AngleQ= Reactive Power (VAR)



## amperes volt 2 3 2 3 3 

## − **+ =**  **θ θ**  **θ** 

## Q P S **θ θ**  

## θ 3 3 1 

## )

( cos factor power S P **= =**  **−** 

## amperes 3

3 LL L 

## V S I **θ** 

## = With IL 

### and an assumption of distribution conductor resistance ( R L 

### ), we calculate hourly line losses ( Pline losses 

### ): 

## watts 2 L L losses line 

## R I P **=** 

## hours - watt 4380 1 4380 1 

# ∑ **∑**

**=**

**=** 

## − **=** n project n baseline 

## P P Savings Energy

For each six- month reporting period (4380 hours) the total line losses per circuit or circuit group are: Energy Savings

from Lower Losses Determine Change in

LossesVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 22 Impact Analysis » Lower Losses › Value of Benefits 

## The energy savings from lower distribution losses saves utilities money on wholesale energy, and reduces carbon emissions and their potential cost.

Value of energy savings for

utilities Value of lower emissions for society 

### ) / ($ ) ( ($) MWh Cost Energy Wholesale MWh Savings Energy Value **× =**  

# ( **)** 

# ( **)** ton Cost CO tons Emissions CO Value MWh tons Factor Emissions CO MWh Savings Energy tons Emissions CO $ ) ( ($) ) ( ) ( 2 2 2 2 **× =**  **× =**  Energy Savings

from Lower LossesVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 23 

### Reported hourly data for real and reactive power (four days in July) Impact Analysis » Lower Losses › Example Analysis – Hourly P/Q Data 

## This project is seeking to improve distribution circuit voltage regulation and reduce losses.

Source: Illustrative results from Navigant analysis 

### Distribution automation project implementing better voltage regulation to improve power quality and reduce losses. This includes the coordinated operation of a voltage regulator with a transformer load -tap changer at a substation.Voltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 24 Impact Analysis » Lower Losses › Example Analysis – Calculation of Losses Savings 

## This project was able to reduce line losses by about one percent over a year. SELECTED DATA (Jan 1 – Dec 31) FULL YEAR DATA (Same) Baseline New Change Baseline New Change Usage Energy 35712.1 35524.1 MWh -0.5% 35712.1 35524.1 MWh -0.5% Reactive Power 17111.8 17094.5 MVARh -0.1% 17111.8 17094.5 MVARh -0.1% Apparent Power 39654.8 39462.0 MVAh -0.5% 39654.8 39462.0 MVAh -0.5% Avg Power Factor 0.904 0.903 0.0% 0.904 0.903 0.0% Avg Current 209.0 208.0 A -0.5% 209.0 208.0 A -0.5% Total Power Losses 1207.66 1195.50 MWh - 1.0% 1207.7 1195.5 MWh - 1.0%

Source: Illustrative results from Navigant analysis Greatest savings happening at peak loadVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 25 Impact Analysis » Lower Losses › Example Analysis – Calculation of Monetary Value 

## Assuming average wholesale prices and a cost for CO2 emissions, the value of reducing losses by one percent is about $840 per year.

year per circuit, per $158 ) / ( 2000 ) / ($ 20 ) ( 160 , 12 ) / ( 3 . 1 ($) per ton $20 of emissions CO for price a and generation y electricit for lbs/kWh 1.3 Assuming year per circuit, per 680 $ ($) ) / ($ 56 ) 50 . 1195 66 . 1207 ( ($) MWh per $56 of price market wholesale average At ) / ($ ) ( ($)

2



## = **× ×**  **= =**  **× −**  **= ×**  **=**

ton lb ton kWh kWh lbs Value Value MWh MWh Value MWh Cost Energy Wholesale MWh Savings Energy ValueVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 26 Impact Analysis » Savings from CVR › Benefits Logic 

## We will work closely with projects implementing CVR to determine how its implementation creates energy and capacity savings.

Energy and

Capacity Savings from CVR On Hourly Circuit Load Data (MW, MVAR) Determine Change in Circuit Load

from CVR

Impact Metric Benefit Analysis Energy and Capacity CVR Factors Value of energy and capacity

savings for

utilities

Value of lower emissions for society Value of electricity savings for customers
CVR Information

from ProjectsVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 27 Impact Analysis » Savings from CVR › The Meaning of CVR 

## Conservation voltage reduction (CVR) reduces customer voltages along a distribution circuit to reduce electricity demand and energy consumption. Studies dating back to the 1980s have shown that small reductions in distribution voltage can reduce electricity demand from customer equipment and save energy. This has become known as “conservation voltage reduction (CVR)”. Recent utility pilot programs have demonstrated that lowering distribution voltage by 1% can reduce demand and energy consumption by 1% or more. “CVR-on” voltage profile Voltage reduced by adjusting the LTC set- point

Distance along circuit Customer Voltage

Distribution Source Voltage “CVR-off” voltage profile Energy and Capacity CVR FactorsVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 28 Impact Analysis » Savings from CVR › Correlating CVR Results with Technology Configurations 

## By analyzing hourly load data and talking with utilities, we will try to correlate CVR factors with VVC technology configurations. CVR reduces demand during peak load periods



# Illustrative Peak demand reduced 

### Some projects who are pursuing CVR will be reporting hourly circuit load data. By analyzing this data we hope to determine how much demand and energy savings each project achieves with its technology configuration. 

# volt watts V P CVRf **∆ ∆**  **=** 

# CVR Factor ( CVRf )
We will work with project teams in the focus group to understand how much distribution voltage was reduced to achieve the reduction in load. Source: Illustrative results from Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 29 Impact Analysis » Savings from CVR › Value of Benefits 

## The energy savings from CVR saves utilities and their customers money on energy and capacity, and reduces carbon emissions.

Value of lower emissions for society 

### ) / ($ ) ( ($) ) / ($ ) ( ($) MW Cost Capacity Wholesale MW Savings Capacity Value MWh Cost Energy Wholesale MWh Savings Energy Value **× =**  **× =**  

# ( **)** 

# ( **)** ton Cost CO tons Emissions CO Value MWh tons Factor Emissions CO MWh Savings Energy tons Emissions CO $ ) ( ($) ) ( ) ( 2 2 2 2 **× =**  **× =**  Energy and

Capacity Savings from CVR On Value of energy and capacity

savings for

utilities Value of electricity savings for customers ) / ($ ) ( ($) kWh Cost y Electricit Average kWh Savings y Electricit Value **× =** Voltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 30 

### Reported hourly data for real and reactive power (four peak demand days in July) Impact Analysis » Savings from CVR › Example Analysis – Hourly P/Q Data 

## This project is seeking to reduce system peak demand with conservation voltage reduction during the summer. Distribution automation project implementing conservation voltage reduction including the coordinated control of a capacitor bank with a transformer load -tap changer at a substation. The CVR action was taken as a way to reduce system peak demand during high load periods in July and August.

Source: Illustrative results from Navigant analysisVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 31 Impact Analysis » Savings from CVR › Example Analysis – Calculation of Capacity Savings 

## This project achieved about a 2% reduction in demand by performing CVR during a peak period in July. SELECTED DATA (July 1 -4, 3PM -9PM) Baseline New Change Usage Energy 5.841 5.770 MW - 1.2% Reactive Power 3.092 2.891 MVAR - 6.5% Apparent Power 6.610 6.456 MVA - 2.3% Avg Power Factor 0.887 0.896 1.0% Avg Current 304.6 295.4 A - 3.0% Total Power Losses 280.2 267.1 kW -4.7%

Source: Illustrative results from Navigant analysis Peak load reductionVoltage and VAR Control Impact Analysis Approach, 11 -30 - 2011 32 Impact Analysis » Savings from CVR › Example Analysis 

## Assuming peak wholesale prices the capacity value of CVR is worth over $15,000 per year, per circuit.

year per million about circuits circuit Value circuit per year per yr kW MW Value MW Cost Capacity Wholesale MW Savings Capacity Value

8 $ 500 ) / ($ 400 , 15 ($) circuits 2000 its of 25% on CVR implements utility large a Assuming , 400 , 15 $ ) / ($ 100 6.456) - 6.610 ( ($) prices sale peak whole At ) / ($ ) ( ($)

**= ×**  **= =**  **− ×**  **= ×**  **=**