Subcontract Report

NREL/SR-550-46763

December 2009

Central Wind Power Forecasting 

Programs in North America 

by Regional Transmission 

Organizations and Electric Utilities

K. Porter and J. Rogers

Exeter Associates, Inc.

Columbia, Maryland
National Renewable Energy Laboratory

1617 Cole Boulevard, Golden, Colorado 80401-3393

303-275-3000 • www.nrel.gov

NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency and Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

Contract No. DE-AC36-08-GO28308

Subcontract Report

NREL/SR-550-46763

December 2009

Central Wind Power Forecasting 

Programs in North America 

by Regional Transmission 

Organizations and Electric Utilities

K. Porter and J. Rogers

Exeter Associates, Inc.

Columbia, Maryland

NREL Technical Monitor: J. Hein

Prepared under Subcontract No. LAM-9-99431-01
NOTICE

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1

Central Wind Power Forecasting Programs in North America

by Regional Transmission Organizations and Electric Utilities

Jennifer Rogers, Exeter Associates, Inc.

Kevin Porter, Exeter Associates, Inc.

December 2009

and incorporating review comments from:

Sanjay Patil, PJM

David Edelson, New York Independent System Operator (NYISO)

David Maggio, Electricity Reliability Council of Texas (ERCOT)

Bart McManus, Bonneville Power Administration (BPA)

Mark Ahlstrom and Joe Sullivan, WindLogics

Martin Hastings and Michael Falvo, Independent Electric System Operator of Ontario

Keith Parks, Xcel Energy

Ulrich Focken, Energy & Meteo

Alain Forcione and Jacques Bourret, Hydro Quebec

Jim Blatchford, California Independent System Operator (CAISO)

James Shen, Alberta Electric System Operator

Kenneth Pennock, Dan Meade and John Zack, AWS Truewind

Erik Ela, National Renewable Energy Laboratory (NREL)

Michael McMullen, Midwest Independent System Operator (Midwest ISO)

Barry Gilman, Southern California Edison (SCE)

Charlie Smith, Utility Wind Integration Group

The following table addresses the implementation of central wind power forecasting by electric utilities 

and regional transmission organizations in North America. The first part of the table focuses on electric 

utilities and regional transmission organizations that have central wind power forecasting in place; the 

second part focuses on electric utilities and regional transmission organizations that plan to adopt 

central wind power forecasting in 2010. Table entries are organized as follows:

• When the wind power forecast was put into operation, or will be in operation.

• What wind power forecast vendor and model is used.

• What wind power forecast tools and techniques are used.

• What applications are the wind power forecast used for.

• How wind power forecasts are paid for.

• What data is required, by wind turbine and wind project.

• How the wind power forecast is conducted.

• Whether a ramp forecast is prepared.

• How the wind power forecast was performed.
2

PJM ERCOT Midwest ISO

Record Peak Demand 144,644 MW 

(August 2, 2006)

62,339 MW 

(August 2006)

116,030 MW 

(July 31, 2006)

Available Generating 

Capacity

164,895 MW 80,076 MW 138,556 MW

Installed Wind Capacity About 2500 MW 8,916 MW About 7200 MW

Area Served 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.

85% of load in Texas; 75% 

of Texas by geography.

All or most of North 

Dakota, South Dakota, 

Nebraska, Minnesota, 

Iowa, Wisconsin, Illinois, 

Indiana, Michigan and 

parts of Montana, 

Missouri, Kentucky, and 

Ohio.

Date of Operation of 

Wind Forecast

April 2009 July 2008 June 2008

Wind Power Forecast 

Vendor

Energy & Meteo GmbH AWS Truewind Energy & Meteo GmbH

Forecast Model Previento eWind Previento

Forecast 

Tools/Techniques

Physical model that uses 

Numerical Weather 

Prediction (NWP)

forecasts as input.

Energy & Meteo uses

NWP input, a combination 

of several numerical 

weather models weighted 

according to the weather 

situation, site-specific 

power curves based on 

historical data, and a 

shorter-term model (0-10 

hours) based on wind 

power measurements and 

NWPs.

Wind turbine deration 

data is integrated in the 

forecast.

AWS Truewind uses a 

composite of the 

individual members of an

ensemble of forecasts for 

each wind project in the 

ERCOT territory.

Uses three NWP models, 

one run every 3 hrs and 

two run every 6 hrs; Wind 

Generation Resource 

(WGR) output model

mixed approach: some 

statistical using WGR data

and some specified power 

curve

Plan to use: 9 NWP model 

ensemble run every 6 hrs;

single NWP model run 

every hr (for Residual Unit 

Commitment); Statistical 

optimized ensemble

procedure that will weight 

ensemble members 

according to performance 

in a rolling training 

sample; Statistical power 

output model: all WGRs

with adequate data

Physical model that uses 

Numerical Weather 

Prediction forecasts as 

input. Energy & Meteo 

uses NWP input, a 

combination of several 

numerical weather models 

weighted according to the 

weather situation, sitespecific power curves 

based on historical data, 

and a shorter-term model 

(0-10 hours) based on 

wind power 

measurements and NWP

input.
3

PJM ERCOT Midwest ISO

Forecast Applications Developing process to 

automate the integration 

of day-ahead wind power 

forecast within existing 

PJM systems to determine

whether there is sufficient 

generation scheduled 

within PJM to meet 

expected load, transaction 

schedules, and reserve 

requirements. 

Day-ahead Unit 

Commitment uses 80% 

exceedance forecast for 

day-ahead planning (i.e., 

80% chance production 

meets or exceeds wind 

power forecast).

Transmission security 

planning and outage 

coordination; and forward 

and intra-day reliability 

analysis. Also can use 

wind power forecast to 

determine impact of wind 

variability on transmission 

flowgates.

Forecast Payment 

Method

PJM pays for the central

wind power forecasting 

service.

ERCOT pays for the central

wind power forecasting 

service.

Midwest ISO pays for the 

central wind power 

forecasting service.

Wind Turbine Data 

Requirements

General turbine 

information (class of 

turbine, turbine capacity); 

min/max wind speed; 

manufacturer power 

curves; geographic 

location; hub height;

ambient temperature 

operating limits and 

information on installation 

of cold weather packages.

Along with these turbinespecific requirements, the 

initial project data 

required includes 

aggregate historic power

output, meteorological 

and outage data; and the 

aggregate reactive 

capability curve.

The number, MW rating, 

and model of turbines. 

Also requires average hub 

height of the project and 

geographic location of the 

center of the wind project.

Turbine 

Outage/Availability data is 

currently voluntary; 

however ERCOT is working 

on making it a 

requirement.

Not applicable - wind 

projects do not provide 

any turbine-specific 

information to Energy & 

Meteo.

Wind turbine outages not 

currently factored into the

wind power forecast, but 

the Midwest ISO 

anticipates doing so in the 

future.

Wind Project Data 

Requirements

Real time aggregate wind 

project MW output.

Must install at least one 

meteorological tower (or 

wind speed and direction 

from selected wind 

turbine anemometers and 

wind vanes) with wind 

speed and wind direction 

data required; 

temperature and pressure 

data preferred; and 

humidity data accepted. 

Outage of turbines ≥ 1MW 

or an outage lasting 

1 hour or more must be 

reported. 

AWS Truewind Data 

Requirements: Observed 

Generation; Observed 

Availability; Observed 

Basepoint; Observed 

Meteorological Data 

(Wind Speed, Wind 

Direction, Temperature, 

and Atmospheric 

Pressure).

Market participants 

required to provide nonbinding day-ahead 

intermittent resource 

forecast to Midwest ISO. 

Midwest ISO provides the 

latitude and longitude 

values of each wind 

project, the hub heights, 

maximum and historical 

MW output, and real-time 

output for each wind 

project to Energy & 

Meteo. Energy & Meteo 

then uses this information 

to create wind power 

forecasts.
4

PJM ERCOT Midwest ISO

Description of Forecast Long Term: Provided 

hourly, from 48 hours 

ahead to 168 hours ahead.

Medium Term: Updated 

from 6 hours ahead to 48 

hours ahead.

Short Term: Updated with 

frequency of every 10

min, forecast interval of 5

min for next 6 hours.

Confidence interval 

defined by PJM.

Forecast on 5 aggregation 

levels.

Statistical power curve for 

each wind project.

Wind power forecasts are 

updated hourly and cover 

1-48 hours ahead. 

Forecast delivered by 15 

minutes past each hour.

Though not currently 

required, the following

will be a requirement of 

the nodal market when it 

is launched in late 2010:

Long-Term (one year) 

forecasts: The long-term 

forecast is a “typical” 

energy profile for each 

day of a future month out 

to 36 months. Wind 

developers will be 

required to submit the 

long-term wind power 

forecast each month for a

rolling 36 month period.

Receives hourly updated 

forecasts from Energy & 

Meteo for each hour of 

the next seven days, for 

over 100 Commercial 

Pricing (CP) nodes.

Forecasts available more 

frequently, but Midwest 

ISO has not yet 

determined that need. 

A short term forecast is 

provided for the next 6 

hours and the remainder 

of the time is considered a 

medium/long-term 

forecast.

Energy & Meteo provides 

forecasts at 4 levels: CP 

nodes, zones, regions and 

all of Midwest ISO. 

Generally, the CP nodes 

represent an individual 

wind project. Three 

different NWP models are 

used for each of these 

levels. Energy & Meteo 

also forecasts wind power 

output as an optimal 

combination of all three 

forecasts.

Statistical power curve for 

each wind project.

Ramp Forecast Updated every 10 minutes 

at 5 min intervals for next 

6 hours.

In process of developing a 

ramp forecast.

Several wind power 

forecasts indicating 

possible ramps are 

provided; however, ramp 

forecasting metrics are

still being developed. 
5

PJM ERCOT Midwest ISO

Forecast Performance 

Metrics

For all of PJM monthly

averaged mean absolute 

error (MAE) for the May 

2009 - July 2009 period

ranged from 4.9% to 5.1% 

for intra-day; 5.9% to 7.9% 

for day-ahead; and 5.2% 

to 5.6% for the evening 

forecast at 4:00 PM, which 

covers 8 to 32 hours 

ahead.

The monthly averaged 

Root Mean Squared Error

(RMSE) for the May 2009 

- July 2009 period ranged

from 6.5% to 7.3% for 

intra-day; 8.3% to 10.3% 

for day-ahead; and 6.9% 

to 7.6% for the evening 

forecast. Forecast 

performance achieved 

without meteorological 

data.

For all of ERCOT, monthly

averaged MAE for the 

4:30 PM system-wide dayahead forecast, for May 

2009-August 2009, ranged 

from 8.28% to 10.73% of 

capacity for all hours.

For all of the Midwest ISO, 

monthly averaged MAE 

for the 4:30 PM forecast 

for day-ahead, for May 

2009 - July 2009, ranged

from 3.3% to 4.5% for all 

hours.

The monthly averaged 

RMSE for intraday (0 – 24 

hour) ranges between 4%

and 7% for the period 

from August 2008 to 

August 2009.

For monthly RMSE for 

day-ahead (24 – 48) 

ranges from 5 to 10%. This 

is the accuracy for the first 

year after the setup.
6

NYISO CAISO SCE Hydro-Québec

Record Peak 

Demand

33,939 MW 

(August 2, 2006)

50,270 MW 

(July 24, 2006)

23,303 MW 

(August 31, 2007)

37,230 MW

(January 16, 2009)

Available 

Generating 

Capacity

38,190 MW (Summer 

2009)

48,954 MW (does 

not include 10,350 

MW of net imports).

SCE considers data 

as confidential.

43,664 MW

Installed Wind 

Capacity

1,275 MW 2,953 MW (CAISO 

total); 1,005 MW in 

CAISO’s wind 

forecasting program.

1,073 MW 657 MW

Areas Served New York 75% of California

load

50,000 square mile 

area of California, 

excluding the City 

of Los Angeles and 

certain other cities. 

Quebec, Canada

Date of Operation

of Wind Forecast

June 2008 – for 

dispatch decisions;

May 2009 – for 

individual wind plant 

economic dispatch 

decisions

June 2004 November 2000 November 2006

Wind Power 

Forecast Vendor

AWS Truewind AWS Truewind AWS Truewind Environment Canada: 

operational GEM 

15-km NWP

Forecast Model eWind eWind eWind Anemos/WPPT; HQ 

proprietary models; 

Forecasting tools 

operated by HQ.

Forecast 

Tools/Techniques

Uses ensemble 

forecasts and 

statistical analysis to 

prepare wind power 

forecast. Uses the 

following inputs: grid 

point output from 

regional-scale and 

global-scale NWP 

models; 

measurement data 

from several 

meteorological 

sensors; highresolution 

geographical data; 

and meteorological 

and generation data 

from wind projects.

Uses ensemble 

forecasts and 

statistical analysis to 

prepare wind power 

forecast. Uses the 

following inputs: grid 

point output from 

regional-scale and 

global-scale NWP 

models; 

measurement data 

from several 

meteorological 

sensors; highresolution 

geographical data; 

and meteorological 

and generation data 

from wind projects.

Uses ensemble 

forecasts and 

statistical analysis 

to prepare wind 

power forecast. 

Uses the following 

inputs: grid point 

output from 

regional-scale and 

global-scale NWP 

models; 

measurement data 

from several 

meteorological 

sensors; highresolution 

geographical data; 

and meteorological 

and generation data 

from wind projects. 

SCE inputs outage 

and curtailment 

data both prior and 

post-production.

Statistical models 

using NWP and actual 

wind project 

generation and 

turbine availability as 

inputs. Extensive R&D 

program on additional 

and complementary 

forecasting tools at 

the Institut de 

recherche d'HydroQuébec (IREQ), HydroQuébec’s research 

institute.
7

NYISO CAISO SCE Hydro-Québec

Forecast 

Applications

Used to review dayahead unit 

commitment 

schedules to ensure 

enough generation is 

committed to meet 

load forecast. Also 

used in real time to 

make real-time 

commitment and 

dispatch decisions.

Used in hour-ahead 

market, as

Participating 

Intermittent 

Resource Program

(PIRP) participants 

must bid wind power 

forecast. Day-ahead 

wind power forecast 

advisory.

Energy scheduling. Day-ahead scheduling; 

Intra-day 

rescheduling; shortterm maintenance 

scheduling. The wind 

power forecast is 

taken into account in 

the intra-day 

scheduling (generation 

scheduled to meet 

expected load, 

transaction schedules, 

and reserve 

requirements).

Forecast Payment 

Method

Fee assessed to each 

wind project. Charge 

includes the sum of a 

monthly fee of $500 

and a separate 

monthly fee of $7.50 

per MW of 

nameplate capacity. 

Fees are subject to 

change as more wind 

projects are added.

Fee assessed on PIRP 

participating 

intermittent 

resources of

$0.10/MWh, and the 

CAISO covers about 

$0.09/MWh from 

within its operating 

budget.

Proposed change: 

Assess $0.10/MWh 

fee to non-PIRP 

intermittent 

resources as well.

SCE pays for the 

wind power 

forecasting service.

HQ pays for the wind

power forecasting 

service.

Wind Turbine 

Data 

Requirements

Turbine 

manufacturer 

specifications; plant 

configuration 

(latitude/longitude of 

each turbine); 

manufacturer’s 

power curve; 

plant/turbine 

availability; plant 

level or turbine level 

power output data.

Real-time telemetry 

data requirements: 

wind speed, wind 

direction, barometric 

pressure, ambient 

temperature, realtime MW production, 

MW production 

revenue meter.

Data requirements:

latitude/longitude and 

elevation of the 

turbine hub height

that will be used as a 

designated turbine. A 

designated turbine is 

the turbine designated 

to send in 

anemometry data to 

represent a 

surrounding group of 

turbines.

MW production 

metering

Operational planning 

data (planned turbine 

availability); turbine 

specifications (power 

curve, control system, 

cold weather 

packages, etc); realtime data including 

kW of active power, 

nacelle direction, 

blade position, 

temperature at nacelle 

level, wind speed, 

wind direction, and 

turbine status.
8

NYISO CAISO SCE Hydro-Québec

Wind Project 

Data 

Requirements

Meteorological data 

from at least one 

point at least every 

15 minutes (to be 

increased in 2010 

requiring data every 

30 seconds, and from 

locations such that 

no individual turbine 

is more than 5 km 

from a reporting 

sensor). On-site 

meteorological data 

[wind speed, wind 

direction, pressure, 

temperature, 

humidity, dew point] 

from multiple 

heights.

Daily penalties of the 

greater of $500 or 

$20/MW for 

persistent lack of or 

bad data.

Minimum 1 met 

tower.

Proposed data 

requirements:

Outage reporting:

Each wind project 

must submit outages 

of at least 1 MW and 

greater if their 

overall capacity is 

greater than 10 MW.

A second met tower

must be installed. 

Alternatively, a 

second data 

recording device may 

be on the same met 

tower, located at 

approximately 30 

meters below the 

average hub height.

Meteorological 

data (wind speed, 

direction, 

temperature, 

humidity).

SCE uses 12 met 

towers (six each in 

Tehachapi and San 

Gorgonio). SCE 

inputs outages and 

curtailments into 

the system both 

before wind

production (for 

forecast 

correction) and 

after wind

production (for 

calibration of the 

system).

Specifications (wind 

project layout).

Real-time data 

including: kW of active 

power; kW power 

available from wind 

turbines, substation, 

and wind project; 

number of available 

turbines; numbers of 

turbines stopped due 

to weak wind, strong 

wind, and low 

temperature.

Meteorological data 

(horizontal and 

vertical wind speed, 

wind direction, 

temperature, 

humidity, and 

atmospheric 

pressure).
9

NYISO CAISO SCE Hydro-Québec

Description of 

Forecast

Day-ahead forecasts 

updated twice daily, 

covering next two 

operating days at 

4 AM and 4 PM.

Real-time forecasts 

updated every 

15 minutes on a 

15-minute interval 

basis, covering an 

8 hour time horizon.

Real-time forecast is 

blended with 

persistence forecast 

to develop wind 

plant schedules in 

real-time 

commitment (which 

looks ahead in 

15-minute intervals 

for 2.5 hours) and 

real-time dispatch, 

which looks ahead in 

5 to 15 minute 

intervals for 60 

minutes. 100% 

persistence used in 

very short-term.

Extended forecasts: 

production (MW) for 

each hour of days 2, 

3, and 4 after 

delivery day; 

delivered by 5:30 AM 

on Thursdays, Fridays 

and selected days 

before scheduling 

holidays.

Next day: production 

(MW) for each hour 

of next calendar day, 

delivered by 5:30 am. 

Next hour: 

production (MW) for 

each of the next 7 

hours, delivered by 

15 minutes after 

each hour and at 

least one hour and 

forty-five minutes

before real time.

Forecast updated 

twice a day (at 

5 AM and 5 pm), 

and both forecasts 

look forward 

7 days.

NWPs updated twice 

daily [at midnight and 

12 PM (UTC)],

covering 48 hours 

ahead. Additional 

6 AM and 6 PM runs 

operational by the end 

of October 2009.

Wind power forecasts 

updated hourly. 

Alarms sent to the 

network and wind 

project operators 

when expected 

storms, icy conditions, 

or very low 

temperatures risking 

turbine shutdowns are 

foreseen.

Ramp Forecast No ramp forecast; 

under consideration.

No ramp forecast

currently working 

with the DOE and 

BPA to develop a 

Short Term Event 

Predictor along with 

a ramp forecast tool.

No ramp forecast; 

under 

consideration.

No ramp forecast.

Forecast 

Performance 

Metrics

For all of the NYISO 

and averaged for all 

intervals between

June 2008 and March 

2009:

MAE of 4.8% for one 

hour ahead forecast.

MAE of 11.5% for 

day-ahead operation.

Average RMSE for 

the period between

July 2008 and July 

2009: 

Day-ahead forecast: 

<15 % RMSE

Hour ahead forecast: 

<7% RMSE

Comparable wind

power forecast 

performance data 

is unavailable.

MAE for March 15, 

2009 – June 1, 2009:

1 hr ahead: 8.5%

4 hrs ahead: 13%

8 hrs ahead: 14.2%

12 hrs ahead: 14.4%

24 hrs ahead: 15%

RMSE for March 15, 

2009 – June 1, 2009:

1 hr ahead: 12.6%

4 hrs ahead: 18%

8 hrs ahead: 19.8%

12 hrs ahead: 20.1%

24 hrs ahead: 20.7%
10

Central Wind Power Forecasting under Development

in the United States and Canada

Xcel Energy

(Colorado)

Ontario IESO Alberta ESO BPA

Record Peak 

Demand

6,884

(Summer 2005)

27,005 MW

(August 1, 2006)

9,806 MW

(December 2008)

10,500 MW

Available

Generating 

Capacity

7,738 MW About 35,465 MW About 12,700 MW 21,580 MW

Installed Wind 

Capacity

1,234 MW About 1,200 MW About 560 MW 2,284 MW

Area Served Xcel Energy serves 

parts of eight states. 

This information is 

applicable only for 

Xcel Energy’s 

operations in 

Colorado.

Ontario, Canada Alberta, Canada 300,000 square miles

All of Washington, 

Oregon, and Idaho, 

and western Montana, 

and small contiguous 

portions of California, 

Nevada, Utah, 

Wyoming, and eastern 

Montana

Status of 

Centralized Wind

Power

Forecasting as of 

November 2009

Not yet launched. 

Expected operation 

date around August 

2010; receipt of test 

forecasts from NCAR 

began September 25, 

2009.

Launch of centralized 

wind power 

forecasting expected 

to start in 2010. 

Request for proposal 

(RFP) expected to be 

issued in late 2009 or 

early 2010. 

Completed a wind 

power forecasting 

pilot project in 

2008; released 

wind power 

forecasting RFP 

issued in June 

2009. Central wind 

power forecasting 

expected to start in 

2010. Proposes to 

recover costs from 

wind generators 

via a $/MWh 

charge.

Not yet launched. 

Through 2009, 

conducting research 

on wind power 

forecasting with 

different vendors.

Wind Power

Forecast Vendor

The National Center 

for Atmospheric 

Research (NCAR), 

with assistance from 

NREL. 

To be determined 

through competitive 

RFP process.

For purposes of 

the pilot, 3 vendors 

were chosen: AWS 

Truewind, Energy 

& Meteo Systems, 

and WEPROG.

AESO expects to 

complete 

contracting with a 

wind power 

forecasting 

provider by the 

end of 2009.

To be determined by 

January 2010 for 

operation by end of 

May 2010. May opt to 

produce the wind 

forecast internally or 

contract with a wind 

forecasting company.
11

Xcel Energy

(Colorado)

Ontario IESO Alberta ESO BPA

Forecast 

Tools/Techniques

NCAR will 

incorporate 

observations of 

current atmospheric 

conditions from a 

variety of sources 

using the Weather 

Research and 

Forecasting model 

and their Real-Time 

Four-Dimensional 

Data Assimilation 

system.

Currently operating a 

decentralized 

forecasting regime, 

whereby wind 

generators submit a 

forecast of 

generation output. 

Wind power forecast 

accuracy subject to 

compliance 

requirements. Wind 

generators are 

required to provide 

updates if actual 

output is reasonably 

expected to differ 

from their original 

forecasts by 2% or 10 

MW, whichever is 

greater.

Real-time scheduling 

done on a 5-minute 

basis, relying on a

telemetry snapshot 

of wind output from

10 minutes prior to 

setting the schedule 

in real time.

Decentralized 

forecasting regime 

will eventually be 

replaced by 

centralized wind 

power forecasting 

(expected to be in 

service in 2010).

In the pilot project:

- AWS Truewind 

utilized the eWind 

system, which 

produced forecasts 

via an assembly of 

physics-based 

(NWP) and 

statistical models.

- Energy & Meteo 

used NWP input, a 

combination of 

several numerical 

weather models 

weighted 

according to the 

weather situation, 

site-specific power 

curves based on 

historical data, and 

shortest-term 

model (0-10 hours) 

based on power 

measurements.

- WEPROG used an 

ensemble 

forecasting system 

with a large 

number of 

members, based 

on their Wind 

Generation Pool 

(WGP) and NWP 

forecasts.

Forecasts to be made 

up to 36 hours ahead 

at four wind projects; 

two in Oregon and 

two in Washington. 

Will focus particularly 

on wind ramps. BPA 

has also installed 14 

met devices in their 

Balancing Authority 

Area. Data feeds from 

met sites will be in 

place by late 2009 for 

forecast displays.

BPA will be developing 

a “wind desk” over the 

next two years to help 

dispatchers.
12

Xcel Energy Ontario IESO Alberta ESO BPA

Data 

Requirements

Collect turbine-level 

and onsite met tower 

detail from wind 

projects into the Xcel 

energy scheduling 

system. They are 

also pursuing remote 

sensing technologies 

for short-term 

forecasting purposes.

To be determined. For the pilot, 

10-minute facility 

power (MW) 

output: historical 

and real time; 

10-minute wind 

speed, wind 

direction, 

temperature and 

pressure: historical 

and real time; 

10-minute realtime turbine 

availability (at 2 

sites only).

Subject to AESO 

rulemaking, AESO 

will impose data 

requirements on 

wind plants, i.e., 

10-minute met 

tower and wind 

generation, and 

available capacity. 

Operational power 

limit will be used 

as well.

Forecasts to 

incorporate up to 

two years of 

historical met and 

power data.

Wind power 

forecasters to use 

metrological data 

taken from wind 

facilities.
13

Xcel Energy Ontario IESO Alberta ESO BPA

Forecast Update 

Frequency

3-km nested 

forecasting grid 

updated every 

3 hours.

As per existing

market rules, the 

market participants

submit day-ahead

wind power forecast 

by 11:00 AM on a 

daily basis. 

Additional forecast 

updates are required 

as conditions change. 

Some wind 

companies update 

their forecast on

hourly basis while 

others may not 

frequently update 

apart from the 

day-ahead forecast. 

Market Assessment 

and Compliance 

Division (MACD) of 

the IESO looks for 

evidence that the 

market participant 

has exercised due 

diligence in 

revising/updating 

dispatch data

(forecasts) to reflect 

changed conditions 

or expected

injection.

Existing 

processes/rules will 

be updated upon 

start of centralized

wind power 

forecasting (expected 

to be in service in 

2010).

For the pilot, three 

forecasters 

delivered a 

48-hour forecast, 

updated each 

hour. Forecasts 

were delivered in 

real time for 

7 existing wind 

generation 

facilities (WGFs), 

5 future WGFs as 

well as 4 regional 

aggregates of 3 

WGFs each, and 

the aggregate of 

the existing WGFs, 

future WGFs and 

all WGFs.

For the RFP, AESO 

wants hourly

forecasts up to 

48 hours ahead; 

and max and min 

forecast at several

confidence levels; 

and forecasted

maximum ramp 

rates within hour 

and notification of 

multi-hour large 

ramps. AESO 

interested in 

expanding 

forecasting to 72, 

96, or 120 hours 

ahead and rolling 

6-hour intra-hour 

forecast at 

10-minute 

intervals.

Forecast likely 

updated every ten 

minutes. It will have 

10-minute predictions 

out 6 hours, and 

hourly predictions out 

36 hours.
14

Table References

PJM

Focken, Ulrich and Lange, Matthias, 2007, Summary of Forecast Methodology of Previento, prepared by Energy &

Meteo GmbH, June 25, 2007, http://www.aeso.ca/downloads/EMSYS_Generic_Summary.pdf.

Personal Communication, Sanjay Patil, PJM Interconnection, August 21, 2009.

Personal Communication, Ulrich Focken, Energy & Meteo Systems, August 20, 2009.

PJM, 2009, PJM 2008 Annual Report, issued April 2009, http://www.pjm.com/about-pjm/who-weare/~/media/about-pjm/newsroom/2008-annual-report.ashx.

PJM, 2009, “PJM Training Course: Wind Generation Operational Considerations”, June 9, 2009, slides.

PJM Intermittent Resource Working Group, 2009, meeting minutes PJM Interconnection, January 8, 2009,

http://www.pjm.com/Media/committees-groups/working-groups/irwg/20090108-minutes.pdf.

PJM Power System Coordination Department, 2009, PJM Manual 14D: Generator Operational Requirements,

Revision 15; effective April 1, 2009,

http://www.pjm.com/documents/~/media/documents/manuals/m14d.ashx.

ERCOT

Botterud, Audun and Wang, Jianhui, 2009, Wind Power Forecasting and Electricity Market Operations,

http://www.usaee.org/usaee2009/submissions/OnlineProceedings/Botterud_etal_paper.pdf.

Doggett, Trip, 2009, “Renewables Development”, ERCOT presentation for the Gulf Coast Power Association Spring 

Conference, April 3, 2009, slides, http://www.gulfcoastpower.org/default/s09doggett.pdf.

ERCOT, 2008a, EMS Wind Power Forecasting Detailed Design (B2) v1.0, March 4, 2008. 

ERCOT, 2008b, PRR794: Meteorological Data Required From QSEs Representing Wind-Powered Generation 

Resources, effective date: 04/01/2009 http://www.ercot.com/mktrules/issues/prr/775-799/794/.

ERCOT, 2009, “ERCOT Quick Facts”, May 2009, http://www.ercot.com/content/news/presentations/

2009/ERCOT%20Quick%20Facts%20May%202009.pdf.

Personal Communication, David Maggio, Electric Reliability Council of Texas, Inc, September 2, 2009.

Personal Communication, Kenneth Pennock, AWS Truewind, LLC, September 4, 2009.
15

Saathoff, Kent, 2009, “Grid Operations and Planning Report”, presentation to the ERCOT Board of Directors,

November 17, 2009, slides, http://www.ercot.com/content/meetings/board/keydocs/

2009/1117/Item_08_-_Grid_Operations_and_Planning_Report.pdf.

Zack, John W, 2008, “Wind Forecasting Efforts to Improve Renewable Penetration”, AWS Truewind presentation

for the Integrated Energy Policy Report workshop, Sacramento, CA, July 31, 2008, slides,

http://www.energy.ca.gov/2008_energypolicy/documents/2008-07-31_workshop/presentations/

Wind_Forecasting_Efforts-Zack.pdf.

Zack, John W, 2009, “Overview of the Current Status and Future Prospects of Wind Power Production Forecasting

for the ERCOT System”, AWS Truewind presentation at an ERCOT workshop, Austin, TX, June 26, 2009,

slides. 

Midwest ISO

Botterud, Audun and Wang, Jianhui, 2009, Wind Power Forecasting and Electricity Market Operations,

http://www.usaee.org/usaee2009/submissions/OnlineProceedings/Botterud_etal_paper.pdf.

Focken, Ulrich and Lange, Matthias, 2007, Summary of Forecast Methodology of Previento, prepared by Energy &

Meteo GmbH, June 25, 2007, http://www.aeso.ca/downloads/EMSYS_Generic_Summary.pdf.

Midwest ISO, 2009, “Corporate Information”, November 2009, http://www.midwestiso.org/publish/Document/

3e2d0_106c60936d4_-7ba50a48324a/Corporate%20Fact%20Sheet%209-1-09.pdf?action=

download&_property=Attachment.

Midwest ISO, 2009, Guide to Day-ahead Intermittent Resource Forecast Data Submittal for Reliability, March 31,

2009, http://www.midwestmarket.org/publish/Document/2c41ee_1200f54a695_-7dd80a48324a/

Intermittent%20Resource%20Forecast%20Submittal%20Guide%20(2).pdf?action=download&_property=

Attachment.

Ontario IESO, 2009, Centralized Renewable Forecasting, draft, February 4, 2009,

http://www.ieso.ca/imoweb/pubs/consult/se57/se57-20090210-Wind-Forecasting.pdf.

Personal Communication, Joe Sullivan, WindLogics, August 26, 2009.

Personal Communication, Kris Ruud, Midwest ISO, November 19, 2009.

Personal Communication, Michael McMullen, Midwest ISO, August 28, 2009.

Personal Communication, Ulrich Focken, Energy & Meteo Systems, August 20, 2009.

NYISO

AWS Truewind, Forecasting: eWind® - Proven, Accurate, Valuable,

http://www.awstruewind.com/forecasting.cfm/details/true (accessed: June 2009).
16

Botterud, Audun and Wang, Jianhui, 2009, Wind Power Forecasting and Electricity Market Operations,

http://www.usaee.org/usaee2009/submissions/OnlineProceedings/Botterud_etal_paper.pdf.

Edelson, David, 2009a, “Changing Operating Standards for Wind in New York: Forecasting and Curtailments”,

AWEA wind and transmission workshop: grid operations and integration session, Overland Park, KS,

March 17-18, 2009, slides.

Edelson, David, 2009b, “Requirements and Expectations for a Quality Wind Forecast”, NYISO presentation for the

wind energy production forecasting webinar, February 9, 2009, slides,

http://www.uwig.org/webinar20909/Edelson.pdf.

Edelson, David, 2009c, “Wind Forecasting and Curtailment Experience at NYISO”, NYISO presentation for the UWIG

Fall Technical Workshop, Cedar Rapids, Iowa, October 7-9, 2009, slides,

http://www.uwig.org/iowawork/Edelson.pdf.

Federal Energy Regulatory Commission, Order Conditionally Accepting Tariff Revisions, 123 FERC ¶ 61,267,

June 17, 2008.

Gonzales, Rick, 2009, “Operational Challenges and Innovative Solutions to Integrating Renewable Resources”,

NYISO presentation, Washington, DC, March 2, 2009, slides,

http://www.ferc.gov/EventCalendar/Files/20090303120300-Gonzales,%20NYISO.pdf.

NYISO, 2009, 2009 Load and Capacity Data: “Gold Book”, version 2, released August 2009.

NYISO Market Issues Working Group, 2007, “Wind Rules and Forecasting Project Update”, draft,

December 14, 2007, slides,

http://www.nyiso.com/public/webdocs/committees/bic_miwg/meeting_materials/2007-12-

14/MIWG_Wind_Forecasting_and_Rules_20071214_v2.pdf.

Ontario IESO, 2009b, Improving Forecasts From Variable Generation, June 11, 2009,

http://www.ieso.com/imoweb/pubs/consult/se57/se57-20090616-Centralized-Wind-Forecasting.pdf.

Personal Communication, David Edelson, New York ISO, August 17, 2009.

Personal Communication, Erik Ela, National Renewable Energy Laboratory, July 13, 2009.

Pike, Robert, 2008, “Wind Rules and Forecasting Proposal”, January 16, 2008, NYISO slides,

http://www.nyiso.com/public/webdocs/committees/bic/meeting_materials/2008-01-

16/BIC_agenda_07_Wind_Forecasting_and_Rules_Proposal_11608.pdf.

CAISO

AWS Truewind, Forecasting: eWind® - Proven, Accurate, Valuable,

http://www.awstruewind.com/forecasting.cfm/details/true (accessed: June 2009).
17

Blatchford, Jim, 2008, “CAISO Supporting Integration of Renewables”, BPA/CAISO international wind forecasting

workshop, July 24-25, 2008, slides, http://www.bpa.gov/corporate/business/innovation/docs/2008/

BPA_California%20ISO%20Cal%20ISO%20Presentation.pdf.

Botterud, Audun and Wang, Jianhui, 2009, Wind Power Forecasting and Electricity Market Operations,

http://www.usaee.org/usaee2009/submissions/OnlineProceedings/Botterud_etal_paper.pdf.

California Energy Commission. Summer 2009 Electricity Supply and Demand Outlook. CEC-200-2009-007, May 

2009. http://www.energy.ca.gov/2009publications/CEC-200-2009-007/CEC-200-2009-007.PDF. 

CAISO, 2009, 2008 California ISO Annual Report, posted September 9, 2009,

http://www.caiso.com/2424/2424b1b6278c0.pdf.

CAISO, 2009, Settlements & Billing: BPM Configuration Guide: Forecasting Service Fee, CC 701, version 1.10,

March 12, 2009, http://www.caiso.com/1b6a/1b6aa70416258.doc.

Helman, Udi, 2009, “Examination of Operational or Dispatch Provisions of Wholesale Tariffs and Market Rules”,

FERC technical conference: integrating renewable resources into the wholesale electric grid, remarks by

Udi Helman, March 2, 2009, http://www.ferc.gov/eventcalendar/Files/20090302091501-

Helman,%20CAISO.pdf.

Ontario IESO, 2009, Improving Forecasts From Variable Generation, June 11, 2009,

http://www.ieso.com/imoweb/pubs/consult/se57/se57-20090616-Centralized-Wind-Forecasting.pdf.

Personal Communication, Jim Blatchford, California ISO, August 14, 2009.

Zack, John W, 2005, “Wind Power Production Forecasting for CAISO PIRP”, workshop on wind resource forecasting 

and RTO/ISO integration, hosted by PJM Interconnection, March 3, 2005, slides.

Zack, John W, 2008, “Wind Forecasting Efforts to Improve Renewable Penetration”, AWS Truewind presentation

for the integrated energy policy report workshop, Sacramento, CA, July 31, 2008, slides,

http://www.energy.ca.gov/2008_energypolicy/documents/2008-07-31_workshop/

presentations/Wind_Forecasting_Efforts-Zack.pdf.

SCE

AWS Truewind, Forecasting: eWind® - Proven, Accurate, Valuable,

http://www.awstruewind.com/forecasting.cfm/details/true (accessed: June 2009).

Bailey, Bruce; Brower, Michael; Cheng, Min; Gilman, Barry; Isaac, Jerry; and Zack, John, 2001, The Value of Wind 

Forecasting to Southern California Edison, http://d.wanfangdata.com.cn/NSTLHY_NSTL_HY2163883.aspx.

Personal Communication, Arthur Canning, Southern California Edison, November 20, 2009.

Personal Communication, Barry Gilman, Southern California Edison, June 26, 2009.
18

Xcel Energy

Parks, Keith, 2009, “Xcel Wind Forecasting Project”, UWIG spring forecasting workshop, February 18-19, 2009

slides.

Personal Communication, Craig Cox, Interwest, November 30, 2009.

Personal Communication, Erik Ela, National Renewable Energy Laboratory, July 13, 2009.

Personal Communication, Keith Parks, Xcel Energy, August 17, 2009.

Personal Communication, Mark Ahlstrom, WindLogics, September 2, 2009.

Public Service Company of Colorado, Notice of Filing of Reduced Firm Demand and Energy Sales Forecasts, before

the Public Utilities Commission of the State of Colorado, Docket No. 07A-447E, March 19, 2009,

http://www.xcelenergy.com/SiteCollectionDocuments/ docs/ 07A447E_PSCoNoticeFilingReducedDemandEnergySalesForecasts_03-19-09.pdf.

University Corporation for Atmospheric Research, 2009, “NCAR Forecasts Will Help Xcel Energy Harness Wind”,

news release, February 4, 2009, http://www.ucar.edu/news/releases/2009/xcel.jsp.

Ontario IESO

Ontario IESO, Demand Overview, http://www.ieso.ca/imoweb/media/md_demand.asp

(accessed November 19, 2009)

Ontario IESO, Supply Overview, http://www.ieso.ca/imoweb/media/md_supply.asp

(accessed November 19, 2009).

Ontario IESO, 2008, “Near Term Wind Forecasting: Improving Final Pre-Dispatch Results Through the Utilization of 

Persistence Forecasting”, presentation to the Wind Power Standing Committee, May 14, 2008, slides,

http://www.ieso.ca/imoweb/pubs/consult/windpower/wpsc-20080514-Item4.pdf.

Ontario IESO, 2009a, Centralized Renewable Forecasting, draft, February 4, 2009,

http://www.ieso.ca/imoweb/pubs/consult/se57/se57-20090210-Wind-Forecasting.pdf.

Ontario IESO, 2009b, “Information and Discussion: Centralized Forecasting for Variable Generation”, June 16, 2009,

slides, http://www.ieso.ca/imoweb/pubs/consult/se57/se57-20090616-Centralized-Wind-Forecastingpres.pdf.

Ontario IESO, 2009c, “Ontario's System Operator to Launch Centralized Wind Forecasting”, news release,

August 18, 2009, http://www.ieso.ca/imoweb/media/md_newsitem.asp?newsID=4842.

Personal Communication, Martin Hastings, Ontario IESO, August 18, 2009.
19

Hydro-Québec 

Balvet, Vincent; Bourret, Jacques; and Maubois, Jean-Emmanuel, 2009, Massive Data Acquisition for the Short

Term Wind Power Forecasting in a Large Grid: The Hydro-Québec SAGIPE System Experience, Power

Systems Conference and Exposition, 2009, PSCE apos;09, IEEE/PES, 15-18 March 2009, Page(s):1 –7,

digital object identifier: 10.1109/PSCE.2009.4839924.

Forcione, Alain; Petrucci, Franco; Roberge, Gaétan; and Yu, Wei, 2008, “Hydro-Québec and Environment Canada

Wind Energy Forecasting Project”, NE Region System Operators’ wind integration seminar, Montréal,

February 13, 2008, slides, http://www.weican.ca/documents/2008/080213-19-AlainForcioneForecasting%20NE%20Region%20Wind%20Integration.pdf.

Hydro-Québec, 2009, Powering Our Future: Annual Report 2008, 

http://www.hydroquebec.com/publications/en/annual_report/index.html.

Hydro-Québec Distribution, 2009, “Electricity Supply for Québec Needs: Call for Tenders Document A/O 2009-02,

Addendum 1”, issue date: June 8, 2009, APPENDIX VII.

Personal Communication, Alain Forcione, Hydro-Québec, August 31, 2009.

Personal Communication, Francis Gosselin, Hydro-Québec, November 20, 2009.

Personal Communication, Jacques Bourret, Hydro-Québec, August 31, 2009.

Alberta ESO

Alberta Electric System Operator, Current Supply Demand Report, 

http://ets.aeso.ca/ets_web/ip/Market/Reports/CSDReportServlet (accessed November 19, 2009).

Alberta Electric System Operator, Wind Power Forecasting Pilot Project,

http://www.aeso.ca/gridoperations/13825.html (accessed June 2009).

Alberta Electric System Operator, 2009a, Powering Albertans, volume 3, issue 1, posted March 5, 2009,

http://www.aeso.ca/downloads/Powering_Albertans_FINAL.pdf.

Alberta Electric System Operator, 2009b, “Wind Integration Stakeholder Session”, August 12, 2009, slides,

http://www.aeso.ca/downloads/AESO_Stakeholder_Session_Presentation_(Aug_12)_(2).pdf.

Alberta Electric System Operator, 2009c, Wind Power Forecasting Service: Request for Proposals, date issued: 

June 23, 2009, http://www.aeso.ca/downloads/Wind_Power_Forecast_RFP_FINAL_23June09.pdf.

AWS Truewind, LLC, 2008, AWS Truewind’s Final Report for the Alberta Forecasting Pilot Project,

submitted: June 25, 2008, http://www.aeso.ca/downloads/Alberta_PP_Final_Report_AWST_Jun25.pdf.
20

Focken, Ulrich and Lange, Matthias, 2008, Final report: Wind power forecasting pilot project in Alberta, Canada,

Energy & Meteo Systems GmbH, May 26, 2008,

http://www.aeso.ca/downloads/Final_report_emsys_lv.pdf.

Frost, Warren, 2009, Final recommendations regarding implementation of market and operational framework 

(MOF) for wind integration in Alberta and AESO response to stakeholder comments, June 18, 2009,

http://www.aeso.ca/downloads/MOF_stakeholder_comments_and_AESO_response_matrix_cover_letter.pdf.

Industry Work Group, 2008, Wind Power Forecasting Pilot Project: Industry Work Group Report, Alberta

Department of Energy, Alberta Electric System Operator, Alberta Energy Research Institute, August 6, 

2008, http://www.aeso.ca/downloads/Work_Group_Paper_Final_(3).pdf.

Jørgensen, Jess and Möhrlen, Corinna, 2008, AESO Wind Power Forecasting Pilot Project: Final Project Report,

WEPROG, May 2008, http://www.aeso.ca/downloads/weprog_pilotproject_finalreport_v4.pdf.

Ontario IESO, 2009a, Centralized Renewable Forecasting, draft, February 4, 2009,

http://www.ieso.ca/imoweb/pubs/consult/se57/se57-20090210-Wind-Forecasting.pdf.

Personal Communication, James Shen, Alberta ESO, September 1, 2009.

Personal Communication, Mark Ahlstrom, WindLogics, September 2, 2009.

BPA

Bonneville Power Administration, 2009, “2008 BPA Facts”, 

http://www.bpa.gov/corporate/about_BPA/Facts/FactDocs/BPA_Facts_2008.pdf.

Bonneville Power Authority, 2009, “Wind Generation Capacity in the BPA Balancing Authority Area”,

September 22, 2009,

http://www.transmission.bpa.gov/business/operations/Wind/WIND_InstalledCapacity_current.xls.

Bonneville Power Administration, 2009, “Wind Integration Initiatives Update”, September 18, 2009, slides.

Personal Communication, Bart McManus, Bonneville Power Administration, August 17, 2009.

Personal Communication, Doug Larson, Western Interstate Energy Board, December 2, 2009.

Personal Communication, Doug Johnson, Bonneville Power Administration, December 3, 2009.

Renewable Energy World, 2009, “BPA Sponsors Wind Forecast Competition”, August 6, 2009,

http://www.renewableenergyworld.com/rea/news/article/2009/08/bpa-sponsors-wind-forecastcompetition.
F1146-E(10/2008)

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Central Wind Power Forecasting Programs in North America by 

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The report addresses the implementation of central wind power forecasting by electric utilities and regional 

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