| Alabama Power Company |
| AmerenUE |
| American Electric Power |
| Asplundh |
| Avista Utilities |
| Baltimore Gas & Electric |
| Bangor Hydro Electric |
| BC Hydro |
| Central Hudson Gas &
Electric |
| Central Vermont Public
Service |
| Choptank Electric
Cooperative |
| Christenson Electric,
Inc. |
| Connecticut Light &
Power Company |
| Consumers Energy Company |
| Dominion Resources
Services, Inc. |
| Dominion Virginia Power |
| Duke Energy |
| Elektro |
| Entergy |
| EON-US |
| Florida Power & Light |
| Georgia Power Company |
| Green Mountain Power |
| Hawaii Electric Light
Company, Inc. |
| Hawaiian Electric
Company, Inc. |
| Henkels & McCoy, Inc. |
| Hydro Ottawa |
| Kansas City Power &
Light |
| Kenergy Corporation |
| Knoxville Utilities
Board |
| Madison Gas & Electric
Company |
| Minnesota Power |
| New Brunswick Power |
| Northeast Utilities |
| NorthWestern Energy |
| Nova Scotia Power Inc. |
| NV Energy |
| Oklahoma Gas and
Electric |
| Oncor Electric Delivery |
| Pacific Gas & Electric
Company |
| Pepco Holdings, Inc. |
| Pike Electric, Inc. |
| PowerSouth Energy
Cooperative |
| PPL |
| Progress Energy |
| PSNC Energy |
| South Carolina Electric
& Gas |
| Southern California
Edison |
| Tennessee Valley
Authority |
| The Empire District
Electric Company |
| Tucson Electric Power |
| UniSource Energy
Services |
| The United Illuminating
Company |
| Vectren Corporation |
| Westar Energy, Inc. |
| Xcel Energy |
