Advanced Energy Systems Inc.
AEI Service LLC
Allegheny Energy, Inc.
Alliant Energy
Alyeska Pipeline Service Company
Ameren Corporation
Arkansas Electric Cooperative Corp
Associated Electric Cooperative, Inc.
BG Group
BrightSource Energy, Inc.
Caithness Corporation
Calpine Corporation
Chevron Global Power Company
Cleco Corporation
CMS Generation
Constellation Energy Group
Covanta Energy Corporation
CPS Energy
Dominion Resources, Inc.
DTE Energy
Duke Energy Corporation
Duquesne Light Holdings
Dynegy
Edison Mission Energy
Electric Reliability Council of Texas, Inc
Energy Future Holdings Corporation
Enpower Management Corp.

Entegra Power Group LLC
enXco
Exelon Generation, LLC
First Solar
FirstEnergy Corp.
Florida Municipal Power Agency
Foster Wheeler Ag
Frederickson Power
Garland Power & Light
Gateway Energy Services
GDF Suez North America
GWF Power Systems
Iberdrola Renewables, Inc.
Idaho Power Company
Integrys Energy Group, Inc.
IPA Operating Company, Inc.
JEA
John Deere Credit
Midland Cogeneration Venture
Mirant Corporation
NAES Corporation
Nebrask Public Power District
New York Power Authority
NextEra Energy Resources, LLC
Northern Star Generation Srvc Co
NRG Energy, Inc.
OGE Energy Corp.
Oglethorpe Power Corporation

Old Dominion Electric Co-op
Pinnacle West Capital Corporation
Portland General Electric Co.
PowerSouth Energy Cooperative
Prairie State Generating Company
Public Service Enterprise Group
Public Utility District of Chelen County #1
Puget Sound Energy
RRI Energy
SCANA Corporation
Seminole Electric Coop
Sempra Global
Siemens Energy
Southern Company
Tenaska Inc.
Terra-Gen Operating Company LLC
Topaz Power Management Group, LP
TransAlta Centralia LLC
TransCanada Corp
Westinghouse Elec. Co
Wind Capital Ventures
Wood Group Power Operation, Inc.
Xcel Energy, Inc.