| Adams Electric Cooperative | IL |
| Adams Electric Cooperative Inc | PA |
| Agralite Electric Cooperative | MN |
| Albemarle Electric Member Corporation | NC |
| Allamakee-Clayton REC | IA |
| Arizona Public Service (APS) | AZ |
| Avangrid | CT, ME, NY |
| Avista Utilities | ID, MT, WA |
| Barron Electric Cooperative | WI |
| Beltrami Electric Coop Inc. | MN |
| BENCO Electric Cooperative | MN |
| Benton County Electric System | TN |
| Benton PUD | WA |
| Berkeley Electric Cooperative | SC |
| Blue Ridge Energy | NC |
| Brunswick Electric Membership Corporation (BEMC) | NC |
| Butler County Rural Electric Cooperative | IA |
| Butler Rural Electric Cooperative Association, Inc. | KS |
| Cape Hatteras Electric Cooperative | NC |
| Carteret-Craven El Member Cooperative | NC |
| CenterPoint Energy | TX |
| Central Electric Member Corporation | NC |
| Central Hudson Gas and Electric | NY |
| Central Lincoln | OR |
| Central Wisconsin Electric Cooperative | WI |
| Choctawhatchee Electric Cooperative (CHELCO) | FL |
| Citizens' Electric Company | PA |
| City of Alcoa Electric Department | TN |
| City of Monroe, NC | NC |
| City of New Bern Public Utilities | NC |
| City of Ocala Electric Utility (OEL) | FL |
| City of Shelby | NC |
| Clallam County PUD | WA |
| Clark County REMC | IN |
| Columbia Rural Electric Association | WA |
| Consolidated Edison of New York and Orange and Rockland Utilities | NY |
| Consumers Energy | MI |
| Consumers Power Inc | OR |
| Continental Divide Electric Cooperative, Inc. | NM |
| Cooperative Light & Power | MN |
| Cordova Electric Cooperative (CEC) | AK |
| CORE Electric Cooperative | CO |
| Cowlitz Public Utility District #1 | WA |
| Dakota Electric Association | MN |
| Delaware Electric Cooperative | DE |
| DEMCO | LA |
| Douglas County PUD | WA |
| Douglas Electric Cooperative | OR |
| Dunn Energy Cooperative | WI |
| Duquesne Light Company | PA |
| East Central Energy | MN, WI |
| Edgecombe-Martin County EMC | NC |
| Empire Electric Association, Inc. (Empire) | CO, UT |
| EnergyUnited Electric Membership Corporation | NC |
| Erwin Utilities | TN |
| Evergy, Inc. | KS, MO |
| Eversource Energy | CT, MA, NH |
| Exelon | DC, IL, MD, PA |
| Federated Rural Electric Association | MN |
| FirstEnergy | OH, WV, VA, MD, PA, NJ |
| Four County Electric Membership Corporation | NC |
| Freeborn Mower Electric Cooperative | IA, MN |
| French Broad Electric Membership Corporation | NC |
| Gaffney Board of Public Works | SC |
| Goodhue County Cooperative Electric Association (GCCEA) | MN |
| Grand Valley Power | CO |
| Grayson Collin Electric Cooperative | TX |
| Great Lakes Energy Cooperative | MI |
| Habersham EMC | GA |
| Halifax Electric Membership Corporation | NC |
| Harriman Utility Board | TN |
| Hawaiian Electric | HI |
| Haywood Electric Membership Corporation | NC |
| Heartland Power Cooperative | IA, MN |
| Henderson Municipal Power & Light (HMP&L) | KY |
| Hingham Municipal Lighting Plant | MA |
| Holy Cross Energy | CO |
| Horry Electric Cooperative | SC |
| Jackson Energy Cooperative | KY |
| Jefferson County PUD | WA |
| Jones-Onslow EMC | NC |
| Kandiyohi Power Cooperative | MN |
| Knoxville Utilities Board | TN |
| La Plata Electric Association | CO |
| Lake Country Power | MN |
| Lake Region Electric Cooperative | MN |
| Lawrenceburg Utility System (LUS) | TN |
| Licking Valley RECC | KY |
| Little River Electric Cooperative | SC |
| Lumbee River EMC | NC |
| Mason County PUD #1 | WA |
| Mason County PUD 3 | WA |
| McLeod Cooperative Power Association | MN |
| Meeker Cooperative Light & Power Association | MN |
| MidAmerican Energy Company | IA, IL, NE, SD |
| Middle Tennessee Electric Membership Corporation (MTE) | TN |
| Midwest Energy & Communications | MI |
| MiEnergy Cooperative | IA, MN |
| Mille Lacs Energy Cooperative | MN |
| Minnesota Valley Electric Cooperative | MN |
| Missoula Electric Coop, Inc | ID, MT |
| Morristown Utilities | TN |
| National Grid | NY, MA, RI |
| Newport Utilities | TN |
| Nobles Cooperative Electric | IA, MN |
| Nolin RECC | KY |
| North Itasca Electric Co-op | MN |
| Northern Lights, Inc. | ID, MT, WA |
| Northern Neck Electric Cooperative | VA |
| Norwood Municipal Light (NMLD) | MA |
| Oklahoma Gas & Electric | AR, OK |
| Orcas Power & Light Cooperative (OPALCO) | WA |
| Pacific Gas & Electric Company (PG&E) | CA |
| PacifiCorp | CA, ID, OR, UT, WA, WY |
| Pee Dee Electric Cooperative, Inc. | SC |
| Pend Oreille Public Utility District No. 1 | WA |
| People's Energy Cooperative | MN |
| Piedmont Electric Cooperative | NC |
| Portland General Electric | OR |
| Poudre Valley Rural Electric Association, Inc. | CO |
| Powder River Energy Corp. | MT, WY |
| Public Utility District No. 1 of Snohomish County (Snohomish County PUD) | WA |
| Puget Sound Energy | WA |
| Pulaski Electric System | TN |
| Randolph Electric Member Corporation | NC |
| Red River Valley Co-op Power Assn. | MN |
| Renville-Sibley Cooperative Power Association | MN |
| Roanoke Electric Membership Corporation | NC |
| Runestone Electric Association | MN |
| Rural Electric Cooperative, Inc. | OK |
| Rutherford Electric Membership Corporation | NC |
| Santee Cooper | SC |
| Seattle City Light | WA |
| Shelby Electric Coop, Inc | IL |
| Sioux Valley Southwestern Electric Inc. (DBA Sioux Valley Energy) | MN, SD |
| South Central Indiana REMC | IN |
| Southern California Edison | CA |
| South River Electric Membership Corporation | NC |
| Stearns Cooperative Association | MN |
| Surry-Yadkin Electric Membership Corporation | NC |
| Tacoma Public Utilities | WA |
| Tanner Electric Cooperative | WA |
| Tideland Electric Membership Corporation | NC |
| Town of Apex | NC |
| Traverse Electric Cooperative, Inc. | MN, ND, SD |
| Trico Electric Cooperative | AZ |
| Tri-County Electric Coop, Inc. | SC |
| Tri-County Electric Membership Corporation | NC |
| Tullahoma Utilities Authority | TN |
| United Power, Inc. | CO |
| Unitil | MA, NH |
| Vermont Electric Cooperative Inc. | VT |
| Victory Electric Cooperative Association, Inc. | KS |
| Wake Electric Membership Corporation | NC |
| Wild Rice Electric Cooperative | MN |
| Wright-Hennepin Cooperative Electric Association | MN |
| Yampa Valley Electric Association, Inc. (YVEA) | CO, WY |