How old are US power plants?
Of the US generating capacity operating at the end of 2025, 59% came online in 2000 or later, but the fleet spans more than a century. The 2000s added the most capacity that is still working, 313.9 GW, ahead of the 1970s (215.2 GW) and the 2020s so far (258.1 GW). Units built before 1980 still make up 25% of nameplate capacity.
Ages here are counted per generator, by the year it began commercial operation. A plant can mix units from very different decades, so the most useful question is usually how old a given unit is, not the plant.
Capacity still operating, by decade built
| Decade | Capacity still operating | Share | Largest fuel |
|---|---|---|---|
| 1900s | 318 MW | 0.0% | Hydroelectric |
| 1910s | 1,941 MW | 0.1% | Hydroelectric |
| 1920s | 4,372 MW | 0.3% | Hydroelectric |
| 1930s | 4,310 MW | 0.3% | Hydroelectric |
| 1940s | 7,669 MW | 0.6% | Hydroelectric |
| 1950s | 35.7 GW | 2.6% | Hydroelectric |
| 1960s | 74.5 GW | 5.4% | Natural gas |
| 1970s | 215.2 GW | 15.6% | Coal |
| 1980s | 147.9 GW | 10.7% | Coal |
| 1990s | 76.2 GW | 5.5% | Natural gas |
| 2000s | 313.9 GW | 22.8% | Natural gas |
| 2010s | 236.6 GW | 17.2% | Natural gas |
| 2020s | 258.1 GW | 18.7% | Solar |
That last note is the key to reading the table. It shows survivors: units from the 1950s and 1960s that have since retired are not counted, and the retirement columns on the home page chart show that side. The 2000s bulge is mostly natural gas: combined-cycle and combustion-turbine units built in a short burst around 2000 to 2003.
Each fuel has its own era
For each fuel, the median year below is the year by which half of today’s capacity of that fuel had come online, weighted by megawatts. The last column names the oldest unit still on the books.
| Fuel | Median year online | Oldest working unit |
|---|---|---|
| Nuclear | 1984 | 1969, Nine Mile Point Nuclear Station (NY) |
| Coal | 1979 | 1930, Neenah Paper Munising Mill (MI) |
| Hydroelectric | 1962 | 1891, Whiting (WI) |
| Pumped-storage hydro | 1977 | 1927, Horse Mesa (AZ) |
| Oil and petroleum | 1975 | 1915, Wakefield (NE) |
| Natural gas | 2002 | 1936, Cushing (OK) |
| Wind | 2016 | 1981, Victory Garden (Tehachapi) (CA) |
| Solar | 2023 | 2001, Springerville (AZ) |
| Battery storage | 2024 | 2003, Battery Energy Storage System (AK) |
Hydropower is the oldest fleet by a wide margin, with a median year of 1962; dams last, and small units from the early twentieth century still turn. Coal (1979) and nuclear (1984) belong to the build-out of the 1970s and 1980s. Natural gas centers on 2002. Wind (2016), solar (2023) and batteries (2024) are almost entirely recent; half of today’s battery capacity came online in 2024 or later.
The oldest unit for a fuel is often tiny. The oldest working hydro and oil units listed above are well under 1 MW each; they remain in the data because their plant as a whole clears the 1 MW threshold. The oldest large units are clearer on the fuel pages, for example coal and nuclear, which chart capacity by the year it came online.
Age is not the same as remaining life
Old does not mean about to close: the hydro units in the table above are more than a century old and still operable. What EIA-860 does record is the operator’s own reported plan: generators with a planned retirement year. Plant pages show those years as dashed tails on the unit chart, exactly as reported for 2025, and the additions and retirements note shows what actually retired over the past decade. To list the oldest plants in a state, open the plant finder sorted by oldest first unit.
The oldest gigawatt-scale plants
Among plants of 1,000 MW or more, the earliest first working units date back to 1936. The list is dominated by hydroelectric plants, whose first units have kept running for decades while newer units were added beside them.
| Plant | State | Main fuel | Capacity | First unit |
|---|---|---|---|---|
| Hoover Dam (AZ) | Arizona | Hydroelectric | 1,039 MW | 1936 |
| Hoover Dam (NV) | Nevada | Hydroelectric | 1,039 MW | 1936 |
| Bonneville | Oregon | Hydroelectric | 1,162 MW | 1938 |
| Grand Coulee | Washington | Hydroelectric | 6,809 MW | 1941 |
| Shawnee | Kentucky | Coal | 1,575 MW | 1953 |
| Barry | Alabama | Natural gas | 3,344 MW | 1954 |
| Kingston | Tennessee | Coal | 1,700 MW | 1954 |
| Chief Joseph | Washington | Hydroelectric | 2,456 MW | 1955 |
Reported retirement plans, 2026 to 2035
Operators reported planned retirement years for 74.4 GW of today’s capacity between 2026 and 2035, and 60% of that is coal. The largest single year in the reports is 2028, with 15.6 GW. These are statements of intent filed for 2025; some plans are postponed and others are added each year, so the table is a snapshot of what operators said, not a schedule.
| Planned year | Capacity | Largest fuel |
|---|---|---|
| 2026 | 8,933 MW | Natural gas |
| 2027 | 10.8 GW | Coal |
| 2028 | 15.6 GW | Coal |
| 2029 | 6,829 MW | Coal |
| 2030 | 6,292 MW | Coal |
| 2031 | 6,351 MW | Coal |
| 2032 | 4,591 MW | Coal |
| 2033 | 4,850 MW | Coal |
| 2034 | 5,674 MW | Coal |
| 2035 | 4,468 MW | Natural gas |
Old and new on the same site
A plant’s age is rarely one number. Of the 2,720 plants of 100 MW or more, 45 have operable units that came online at least 50 years apart. The widest span belongs to Holtwood in Pennsylvania, where the oldest working unit dates from 1910 and the newest from 2013. Sites like these keep their grid connection, water supply and land while the machines on them change, which is why the unit-by-unit chart on each plant page is drawn per generator instead of giving the plant a single age.
The same logic explains why the “first unit” year in the plant finder can be later than the year a site first made electricity: when the original units retire, the oldest unit still on the books becomes the reference.
Source: U.S. Energy Information Administration, Form EIA-860 (Annual Electric Generator Report), 2025 final data (Sep 2026). Downloaded 2026-10-28. Figures are computed by GridPlants from the plant, generator and ownership files; see how to read the data.