Directory of Power Plants in the United States
| Plant Name | Utility | Location | Balancing Authority | Annual Generation | Plant Date | Last Update | Fuel Types |
|---|---|---|---|---|---|---|---|
| Oak Hill - Dry Creek | Vistra Zero LLC | Henderson, TX | Electric Reliability Council of Texas, Inc. (ERCO) | 103.1 GWh | - | May 2026 | Solar |
| OES Biogas Power | Organic Energy Solutions, Inc. | San Bernardino, CA | California Independent System Operator (CISO) | 4.9 GWh | - | Dec 2024 | Other Biomass Gas |
| Optimist | Origis Energy USA, Inc | West Point, MS | Tennessee Valley Authority (TVA) | 198.2 GWh | - | May 2026 | Solar : 99.8% |
| Ocoee 1 | Tennessee Valley Authority | Benton, TN | Tennessee Valley Authority (TVA) | 65.6 GWh | Dec 1911 | Dec 2025 | Water |
| Ocoee 2 | Tennessee Valley Authority | Benton, TN | Tennessee Valley Authority (TVA) | 98.1 GWh | Sep 1913 | Dec 2025 | Water |
| Oswego Falls East | Erie Boulevard Hydropower LP | Fulton, NY | New York Independent System Operator (NYIS) | 22.2 GWh | Dec 1913 | Dec 2025 | Water |
| Oswego Falls West | Erie Boulevard Hydropower LP | Fulton, NY | New York Independent System Operator (NYIS) | 3.4 GWh | Dec 1913 | Dec 2025 | Water |
| Oneida | PacifiCorp | Riverdale, ID | PacifiCorp East (PACE) | 39.4 GWh | Jun 1915 | Dec 2025 | Water |
| Oconto Falls Upper | Eagle Creek Renewable Energy, LLC | Oconto Falls, WI | Midcontinent Independent System Operator, Inc. (MISO) | 12.0 GWh | Dec 1917 | Dec 2025 | Water |
| Oak Grove | Portland General Electric Co | Estacada, OR | Portland General Electric Company (PGE) | 142.1 GWh | Jul 1924 | Dec 2025 | Water |
| Oakdale | Northern Indiana Pub Serv Co | Monticello, IN | Midcontinent Independent System Operator, Inc. (MISO) | 15.0 GWh | Oct 1925 | Feb 2025 | Water |
| Ohio Falls | Louisville Gas & Electric Co | Shippingport Island, KY | Louisville Gas and Electric Company and Kentucky Utilities Company (LGEE) | 219.5 GWh | Dec 1927 | Dec 2025 | Water |
| Oxford Dam | Duke Energy Carolinas, LLC | Conover, NC | Duke Energy Carolinas (DUK) | 86.5 GWh | Mar 1928 | Dec 2025 | Water |
| Ozark Beach | Empire District Electric Co | Forsyth, MO | Southwest Power Pool (SWPP) | 40.3 GWh | May 1931 | Dec 2025 | Water |
| Ottumwa City of | City of Ottumwa - (IA) | Ottumwa, IA | Midcontinent Independent System Operator, Inc. (MISO) | 2.9 GWh | Jul 1931 | Dec 2025 | Water |
| Osage Dam | Union Electric Co - (MO) | Eldon, MO | Midcontinent Independent System Operator, Inc. (MISO) | 498.9 GWh | Sep 1931 | Dec 2025 | Water |
| Ocoee 3 | Tennessee Valley Authority | Benton, TN | Tennessee Valley Authority (TVA) | 141.3 GWh | Mar 1943 | Dec 2025 | Water |
| Oberlin (OH) | City of Oberlin - (OH) | Oberlin, OH | PJM Interconnection, LLC (PJM) | 593.0 MWh | Dec 1947 | Dec 2025 | Natural Gas : 87.7% Distillate Fuel Oil : 12.3% |
| O H Hutchings | Kimura Power LLC | Miamisburg, OH | PJM Interconnection, LLC (PJM) | 397.0 MWh | Jun 1948 | Dec 2024 | Natural Gas |
| Orrville | City of Orrville - (OH) | Orrville, OH | PJM Interconnection, LLC (PJM) | 29.3 GWh | Dec 1948 | Dec 2025 | Bituminous Coal : 54.3% Natural Gas : 45.7% |
| Oakdale Power Station | Massachusetts Water Res Auth | West Boylston, MA | ISO New England (ISNE) | 1.4 GWh | Apr 1951 | Dec 2025 | Water |
| Ogden | City of Ogden - (IA) | Ogden, IA | Midcontinent Independent System Operator, Inc. (MISO) | 73.0 MWh | Jun 1951 | Dec 2025 | Distillate Fuel Oil |
| Oxford (NE) | Village of Oxford - (NE) | Oxford, NE | Southwest Power Pool (SWPP) | 82.0 MWh | Jul 1953 | Dec 2025 | Natural Gas : 67.3% Distillate Fuel Oil : 32.7% |
| Oberlin (KS) | City of Oberlin - (KS) | Oberlin, KS | Southwest Power Pool (SWPP) | 9.8 MWh | Dec 1953 | Dec 2025 | Distillate Fuel Oil |
| Old Hickory | USCE-Nashville District | Hendersonville, TN | Tennessee Valley Authority (TVA) | 324.7 GWh | Mar 1957 | Dec 2025 | Water |
| Osborne | City of Osborne - (KS) | Osborne, KS | Southwest Power Pool (SWPP) | 30.4 MWh | May 1957 | Dec 2025 | Distillate Fuel Oil : 61.7% Natural Gas : 38.3% |
| Oliver Dam | Georgia Power Co | Columbus, GA | Southern Company Services, Inc. - Trans (SOCO) | 120.3 GWh | Jun 1959 | Dec 2025 | Water |
| Ocotillo | Arizona Public Service Co | Tempe, AZ | Arizona Public Service Company (AZPS) | 378.7 GWh | Feb 1960 | May 2026 | Natural Gas |
| Oxbow (OR) | Idaho Power Co | Oxbow, OR | Idaho Power Company (IPCO) | 990.3 GWh | Jun 1961 | Dec 2025 | Water |
| Oahe | USACE-Omaha | Pierre, SD | Southwest Power Pool (SWPP) | 2.0 TWh | Mar 1962 | Dec 2025 | Water |
| Ord | City of Ord - (NE) | Ord, NE | Southwest Power Pool (SWPP) | 119.0 MWh | Dec 1962 | Dec 2025 | Distillate Fuel Oil : 99.4% Natural Gas : 0.6% |
| Osage (IA) | City of Osage - (IA) | Osage, IA | Midcontinent Independent System Operator, Inc. (MISO) | 5.5 GWh | Aug 1963 | Dec 2025 | Wind : 81.8% Solar : 18.2% |
| Oxbow (CA) | Placer County Water Agency - (CA) | Foresthill, CA | California Independent System Operator (CISO) | 23.2 GWh | Sep 1966 | Dec 2025 | Water |
| Oak Bluffs Diesel Generating Facility | Vineyard Reliability LLC | Oak Bluffs, MA | ISO New England (ISNE) | 2.9 GWh | Dec 1968 | Sep 2025 | Distillate Fuel Oil |
| Oconto Falls Lower | Eagle Creek Renewable Energy, LLC | Oconto Falls, WI | Midcontinent Independent System Operator, Inc. (MISO) | 6.0 GWh | Dec 1970 | Dec 2025 | Water |
| Orrtanna | Orrtanna Power, LLC | Orrtanna, PA | PJM Interconnection, LLC (PJM) | 417.0 MWh | Apr 1971 | Dec 2025 | Distillate Fuel Oil |
| Ormond Beach | Ormond Beach Power, LLC | Oxnard, CA | California Independent System Operator (CISO) | 4.9 GWh | Jul 1971 | May 2026 | Natural Gas |
| O W Sommers | City of San Antonio - (TX) | San Antonio, TX | Electric Reliability Council of Texas, Inc. (ERCO) | 2.3 TWh | Mar 1972 | Dec 2025 | Natural Gas |
| Ozark | USCE-Little Rock District | Ozark, AR | Southwestern Power Administration (SPA) | 314.7 GWh | Oct 1972 | Dec 2024 | Water |
| Oconee | Duke Energy Carolinas, LLC | Seneca, SC | Duke Energy Carolinas (DUK) | 22.0 TWh | Jun 1973 | May 2026 | Nuclear |
| Oswego Harbor Power | Oswego Harbor Power | Oswego, NY | New York Independent System Operator (NYIS) | 130.8 GWh | May 1975 | Feb 2026 | Residual Fuel Oil : 98.0% Natural Gas : 2.0% |
| Old Faithful | NorthWestern Energy (MT wind/thermal) | Yellowstone, WY | NorthWestern Corporation (NWMT) | 203.0 MWh | Nov 1979 | Dec 2025 | Distillate Fuel Oil |
| Ottumwa | Interstate Power and Light Co | Ottumwa, IA | Midcontinent Independent System Operator, Inc. (MISO) | 3.5 TWh | Apr 1981 | May 2026 | Subbituminous Coal : 99.6% |
| Oxnard Wastewater Treatment Plant | City of Oxnard - (CA) | Oxnard, CA | California Independent System Operator (CISO) | 3.0 GWh | Jul 1981 | May 2026 | Other Biomass Gas : 97.6% Natural Gas : 2.4% |
| Owatonna | City of Owatonna - (MN) | Owatonna, MN | Midcontinent Independent System Operator, Inc. (MISO) | 1.4 GWh | Mar 1982 | Dec 2025 | Natural Gas |
| Oak Creek Energy Systems I | Terra-Gen Operating Co-Wind | Mojave, CA | California Independent System Operator (CISO) | 57.3 GWh | May 1982 | Dec 2025 | Wind |
| Oxnard | Procter&Gamble Paper Products Co-Oxnard | Oxnard, CA | California Independent System Operator (CISO) | 425.0 GWh | Jun 1982 | May 2026 | Natural Gas |
| Ottauquechee Hydro | Green Mountain Power Corp | N. Hartland, VT | ISO New England (ISNE) | 2.8 GWh | Mar 1983 | Dec 2025 | Water |
| Orca | Cordova Electric Coop, Inc | Cordova, AK | 4.3 GWh | Sep 1984 | Dec 2025 | Distillate Fuel Oil | |
| Opal Springs Hydro | Deschutes Valley Water District | Culver, OR | PacifiCorp West (PACW) | 28.0 GWh | Dec 1984 | Dec 2025 | Water |
| Otis Hydro | Eagle Creek Renewable Energy, LLC | Livermore Falls, ME | ISO New England (ISNE) | 38.0 GWh | Dec 1984 | May 2026 | Water |
| Odyssey Energy Altura Cogen, LLC | Odyssey Operating Services | Channelview, TX | Electric Reliability Council of Texas, Inc. (ERCO) | 3.4 TWh | Oct 1985 | May 2026 | Natural Gas |
| Omega Hills Gas Recovery | WM Renewable Energy LLC | Germantown, WI | Midcontinent Independent System Operator, Inc. (MISO) | 77.8 GWh | Nov 1985 | May 2026 | Landfill Gas |
| Oswego County Energy Recovery | Oswego County - (NY) | Fulton, NY | New York Independent System Operator (NYIS) | 5.6 GWh | Jan 1986 | Dec 2025 | Non-biogenic Municipal Solid Waste : 55.0% Biogenic Municipal Solid Waste : 45.0% |
| Oxnard Paper Mill | New-Indy, Oxnard LLC | Oxnard, CA | California Independent System Operator (CISO) | 150.5 GWh | Feb 1986 | May 2026 | Natural Gas |
| Ormesa I | Ormat Nevada Inc | Holtville, CA | Imperial Irrigation District (IID) | 70.2 GWh | Nov 1986 | Dec 2024 | Geothermal |
| Orchard Avenue 1 | Yakima-Tieton Irrigation Dist | Yakima, WA | PacifiCorp West (PACW) | 2.9 GWh | Feb 1987 | Oct 2025 | Water |
| Olmsted Waste Energy | Olmsted County Public Works - (MN) | Rochester, MN | Midcontinent Independent System Operator, Inc. (MISO) | 47.5 GWh | Mar 1987 | Dec 2025 | Non-biogenic Municipal Solid Waste : 54.7% Biogenic Municipal Solid Waste : 44.8% Natural Gas : 0.5% |
| Ogdensburg | Ampersand Ogdensburg Hydro, LLC | Ogdensburg, NY | New York Independent System Operator (NYIS) | 4.4 GWh | Nov 1987 | Dec 2025 | Water |
| Ormesa II | Ormat Nevada Inc | Holtville, CA | Imperial Irrigation District (IID) | 131.7 GWh | Apr 1989 | Dec 2024 | Geothermal |
| Ormesa III | Ormat Nevada Inc | Holtville, CA | Imperial Irrigation District (IID) | 44.4 GWh | Apr 1989 | Dec 2024 | Geothermal |
| Olsen | Olsen Power Partners | Whitmore, CA | California Independent System Operator (CISO) | 15.3 GWh | Dec 1989 | Dec 2025 | Water |
| Oroville Cogeneration, LLC | Apex Power Generation Corp. | Oroville, CA | California Independent System Operator (CISO) | 115.6 MWh | Dec 1989 | Dec 2025 | Natural Gas |
| Ocean State Power | Ocean State Power Co | Harrisville, RI | ISO New England (ISNE) | 1.0 TWh | Nov 1990 | Dec 2025 | Natural Gas : 99.7% |
| Ocean State Power II | Ocean State Power II | Harrisville, RI | ISO New England (ISNE) | 576.9 GWh | Sep 1991 | Dec 2025 | Natural Gas : 99.9% |
| Orlando Cogen LP | Florida Municipal Power Agency (FL) | Orlando, FL | Duke Energy Florida, Inc. (FPC) | 704.8 GWh | Aug 1993 | Dec 2024 | Natural Gas |
| Oyster Creek Unit VIII | Dow Chemical Company-Oyster Creek VIII | Freeport, TX | Electric Reliability Council of Texas, Inc. (ERCO) | 2.6 TWh | Sep 1994 | May 2026 | Natural Gas : 99.8% |
| Onondaga County Resource Recovery | Covanta Onondega LP | Jamesville, NY | New York Independent System Operator (NYIS) | 179.4 GWh | Oct 1994 | May 2026 | Non-biogenic Municipal Solid Waste : 53.8% Biogenic Municipal Solid Waste : 44.0% Natural Gas : 2.2% |
| Orange Cogeneration Facility | Northern Star Generation Services Co LLC | Bartow, FL | Duke Energy Florida, Inc. (FPC) | 374.6 GWh | Jan 1995 | Dec 2025 | Natural Gas |
| Opryland USA | Gaylord Entertainment Co | Nashville, TN | Tennessee Valley Authority (TVA) | 8.0 GWh | Jun 1995 | May 2026 | Natural Gas |
| Otsego Mill Power Plant | Otsego Paper Inc | Otsego, MI | Midcontinent Independent System Operator, Inc. (MISO) | 162.5 GWh | Oct 1995 | Dec 2025 | Natural Gas |
| Okeelanta Cogeneration | New Hope Power Company | South Bay, FL | Florida Power & Light Co. (FPL) | 53.7 GWh | Dec 1995 | May 2026 | Agricultural By-Products : 97.4% Natural Gas : 2.6% |
| Ocean County Landfill | NextEra Renewable Fuels, LLC | Manchester, NJ | PJM Interconnection, LLC (PJM) | 64.3 GWh | Jan 1997 | Dec 2024 | Landfill Gas |
| Orrville Peaking | American Mun Power-Ohio, Inc | Orrville, OH | PJM Interconnection, LLC (PJM) | 271.0 MWh | Jun 1999 | Dec 2025 | Distillate Fuel Oil |
| Oxford (KS) | City of Oxford - (KS) | Oxford, KS | Southwest Power Pool (SWPP) | 4.0 MWh | Jun 1999 | Dec 2025 | Distillate Fuel Oil |
| Oak Point Cogen | Chevron Oronite Co LLC | Belle Chasse, LA | Midcontinent Independent System Operator, Inc. (MISO) | 97.8 GWh | Sep 1999 | Dec 2025 | Natural Gas |
| Odessa-Ector Power Plant | LaFrontera Holdings LLC | Odessa, TX | Electric Reliability Council of Texas, Inc. (ERCO) | 8.5 TWh | Jun 2001 | May 2026 | Natural Gas |
| Old Gold Energy Center, LLC | Old Gold Energy Center, LLC | Joice, IA | Midcontinent Independent System Operator, Inc. (MISO) | 57.1 GWh | Sep 2001 | Dec 2025 | Wind |
| Osceola Generating Station (FL) | Orlando Utilities Comm | St. Cloud, FL | Duke Energy Florida, Inc. (FPC) | 3.7 GWh | Nov 2001 | Dec 2025 | Natural Gas : 85.7% Distillate Fuel Oil : 14.3% |
| Ontelaunee Energy Center | Ontelaunee Energy Center | Reading, PA | PJM Interconnection, LLC (PJM) | 3.7 TWh | Apr 2002 | May 2026 | Natural Gas |
| Oleander Power Project LP | Oleander Holdings LLC | Cocoa, FL | Florida Power & Light Co. (FPL) | 579.6 GWh | May 2002 | Dec 2025 | Natural Gas : 99.8% |
| Oneta Energy Center | Oneta Power LLC | Broken Arrow, OK | Southwest Power Pool (SWPP) | 4.4 TWh | Jun 2002 | May 2026 | Natural Gas |
| Oswegatchie | Erie Boulevard Hydropower LP | Edwards, NY | New York Independent System Operator (NYIS) | 7.0 GWh | Jul 2002 | Dec 2025 | Water |
| Ouachita | Entergy Louisiana LLC | Sterlington, LA | Midcontinent Independent System Operator, Inc. (MISO) | 4.4 TWh | Jul 2002 | May 2026 | Natural Gas |
| Onancock Diesel Generation Facility | Old Dominion Electric Coop | Onancock, VA | PJM Interconnection, LLC (PJM) | 578.0 MWh | Oct 2002 | Dec 2025 | Distillate Fuel Oil |
| Overall Road Station | City of Farmington - (MO) | Farmington, MO | Midcontinent Independent System Operator, Inc. (MISO) | 29.0 MWh | Feb 2003 | Dec 2025 | Distillate Fuel Oil |
| Osawatomie | Evergy Metro | Miami, KS | Southwest Power Pool (SWPP) | 53.6 GWh | May 2003 | Dec 2025 | Natural Gas |
| Oklahoma Wind Energy Center | FPL Energy Oklahoma Wind LLC | Woodward, OK | Southwest Power Pool (SWPP) | 140.6 GWh | Sep 2003 | Dec 2025 | Wind |
| Ontario LFGTE | Seneca Energy II | Stanley, NY | New York Independent System Operator (NYIS) | 77.7 GWh | Oct 2003 | Dec 2025 | Landfill Gas |
| Oak Ridge LFGTE | Wabash Valley Power Assn, Inc | Logansport, IN | Midcontinent Independent System Operator, Inc. (MISO) | 23.0 GWh | Nov 2003 | Dec 2025 | Landfill Gas |
| One Market Plaza | Paramount Group Inc | San Francisco, CA | California Independent System Operator (CISO) | 1.2 GWh | Nov 2003 | Dec 2025 | Natural Gas |
| Orchard Park | Borough of Chambersburg - (PA) | Chambersburg, PA | PJM Interconnection, LLC (PJM) | 49.0 GWh | Nov 2003 | May 2026 | Natural Gas : 96.0% Distillate Fuel Oil : 4.0% |
| Otter Creek Ethanol Poet - Ashton | Otter Creek Ethanol LLC - Poet Ashton | Ashton, IA | Midcontinent Independent System Operator, Inc. (MISO) | 44.6 GWh | Feb 2004 | May 2026 | Natural Gas |
| Osprey Energy Center Power Plant | Duke Energy Florida, LLC | Auburndale, FL | Tampa Electric Company (TEC) | 3.4 TWh | Apr 2004 | May 2026 | Natural Gas |
| Oasis Wind | Terra-Gen Operating Co-Wind | Mojave, CA | California Independent System Operator (CISO) | 221.1 GWh | Nov 2004 | Dec 2025 | Wind |
| Orange Street G1 | Town of Bedford - (VA) | Bedford, VA | PJM Interconnection, LLC (PJM) | 269.0 MWh | Jun 2005 | Dec 2025 | Distillate Fuel Oil |
| OREG 1 Inc | Ormat Nevada Inc | Culbertson, MT | Southwest Power Pool (SWPP) | 124.0 GWh | Jun 2006 | May 2026 | Waste Heat |
| Old Trail Wind Farm | Old Trail Wind Farm LLC | Ellsworth, IL | PJM Interconnection, LLC (PJM) | 563.5 GWh | Nov 2007 | May 2026 | Wind |
| Odin Wind Farm LLC | Aspenall Energies (Delaware), LLC | Mountainlake, MN | Midcontinent Independent System Operator, Inc. (MISO) | 32.4 GWh | Apr 2008 | Dec 2025 | Wind |
| Osceola Windpower LLC | Osceola Windpower LLC | Harris, IA | Southwest Power Pool (SWPP) | 383.8 GWh | Jun 2008 | May 2026 | Wind |
Summary of Power Plants By State
Figures are based on May 2026 generation numbers.| State | Rank | Active Plants | May 2026 Generation |
|---|---|---|---|
| Alabama | # 8 | 77 | 11,823.92 GWh |
| Alaska | # 48 | 140 | 513.29 GWh |
| Arizona | # 14 | 196 | 9,091.99 GWh |
| Arkansas | # 25 | 117 | 4,873.33 GWh |
| California | # 4 | 1,740 | 15,360.54 GWh |
| Colorado | # 31 | 308 | 4,156.36 GWh |
| Connecticut | # 35 | 173 | 3,391.33 GWh |
| Delaware | # 49 | 35 | 236.45 GWh |
| District of Columbia | # 51 | 17 | 14.46 GWh |
| Florida | # 2 | 342 | 25,093.89 GWh |
| Georgia | # 6 | 250 | 12,138.02 GWh |
| Hawaii | # 46 | 70 | 762.50 GWh |
| Idaho | # 41 | 151 | 1,963.84 GWh |
| Illinois | # 5 | 494 | 14,816.74 GWh |
| Indiana | # 15 | 222 | 7,662.28 GWh |
| Iowa | # 21 | 297 | 5,720.38 GWh |
| Kansas | # 24 | 188 | 5,118.39 GWh |
| Kentucky | # 23 | 61 | 5,471.28 GWh |
| Louisiana | # 13 | 90 | 9,131.60 GWh |
| Maine | # 44 | 242 | 1,130.78 GWh |
| Maryland | # 37 | 228 | 3,103.37 GWh |
| Massachusetts | # 45 | 666 | 1,073.93 GWh |
| Michigan | # 11 | 276 | 9,774.25 GWh |
| Minnesota | # 28 | 790 | 4,567.82 GWh |
| Mississippi | # 20 | 60 | 6,404.61 GWh |
| Missouri | # 22 | 129 | 5,701.36 GWh |
| State | Rank | Active Plants | May 2026 Generation |
|---|---|---|---|
| Montana | # 40 | 71 | 2,053.07 GWh |
| Nebraska | # 36 | 126 | 3,193.89 GWh |
| Nevada | # 33 | 117 | 3,848.29 GWh |
| New Hampshire | # 43 | 57 | 1,198.65 GWh |
| New Jersey | # 30 | 398 | 4,274.91 GWh |
| New Mexico | # 29 | 158 | 4,513.39 GWh |
| New York | # 10 | 1,064 | 10,643.78 GWh |
| North Carolina | # 9 | 913 | 11,481.42 GWh |
| North Dakota | # 34 | 59 | 3,601.34 GWh |
| Ohio | # 7 | 211 | 11,886.21 GWh |
| Oklahoma | # 17 | 144 | 7,547.66 GWh |
| Oregon | # 27 | 281 | 4,575.23 GWh |
| Pennsylvania | # 3 | 258 | 18,234.28 GWh |
| Rhode Island | # 47 | 107 | 580.94 GWh |
| South Carolina | # 16 | 209 | 7,632.32 GWh |
| South Dakota | # 42 | 53 | 1,802.78 GWh |
| Tennessee | # 19 | 99 | 6,454.94 GWh |
| Texas | # 1 | 1,019 | 50,690.02 GWh |
| Utah | # 39 | 128 | 2,809.26 GWh |
| Vermont | # 50 | 118 | 186.37 GWh |
| Virginia | # 18 | 250 | 7,445.56 GWh |
| Washington | # 12 | 134 | 9,231.20 GWh |
| West Virginia | # 32 | 41 | 4,142.41 GWh |
| Wisconsin | # 26 | 266 | 4,582.07 GWh |
| Wyoming | # 38 | 69 | 2,983.81 GWh |