Share of utility-scale installed capacity, by source
This interactive map and sortable table show every utility-scale petroleum-fired power plant in the United States, all 1,014 plants of 1 MW or larger in the U.S. Energy Information Administration’s EIA-860 (2025 early release) whose primary fuel is petroleum (diesel/distillate, residual fuel oil, kerosene, jet fuel, waste oil or petroleum coke), color-coded by technology: reciprocating engine (746), combustion turbine (198), steam turbine (32) and combined cycle (6). Natural gas plants are excluded (including dual-fuel gas sites), so there is no overlap with the Natural Gas page. Petroleum is a small, mostly standby slice of US power, used for backup and peaking, especially in Alaska, Hawaii, Puerto Rico and remote grids. Plants are shown across all statuses: active (570), standby (256), in development (4) and decommissioned (184). Together, the 570 active petroleum plants mapped here have a combined capacity of about 21,400 MW (~21 GW). Source: U.S. EIA Form EIA-860 (2025 early release), Schedules 2 (Plant) and 3 (Generator), with every plant’s status and capacity then reviewed against the Preliminary Monthly Electric Generator Inventory (EIA-860M), June 2026.
Capacity is what is installed; generation is what actually ran. Petroleum holds 1.62% of US utility-scale generating capacity and produced 0.44% of the electricity in 2025, an implied capacity factor of 10.3% on a nameplate basis. Nuclear is the extreme case in one direction, at 7.32% of capacity for 17.70% of generation; solar is the extreme in the other, at 12.50% for 6.67%.
Sources, basis and how the totals reconcile
Sources. Generation is EIA Electric Power Monthly, Table 1.1, Net Generation by Energy Source: Total (All Sectors), annual 2025 row. EIA marks 2025 and 2026 values as preliminary; 2024 and earlier are final, so these shares may be revised. Capacity is this site’s own datasets from EIA-860 (2025 early release), reconciled against EIA-860M (June 2026).
Basis. Both charts cover utility-scale plants of 1 MW or larger, generating sources only. Battery storage is excluded from the capacity chart because it shifts power rather than producing it, and estimated small-scale rooftop solar (93,148 GWh in 2025) is excluded from the generation chart so the two stay comparable.
Totals. The generation slices sum to 4,434,820 GWh. EIA’s published net total is 4,429,502 GWh, being that figure less 5,320 GWh of net pumped-storage hydro, which EIA reports as a negative because pumping consumes more electricity than generation returns, and a further 2 GWh that EIA attributes to independent rounding. Pumped storage is left out of the pie because a negative value cannot be drawn as a slice. Percentages use largest-remainder rounding at two decimal places so each chart adds to 100.00%.
Category notes. EIA reports wind, biomass and geothermal as one 526,246 GWh category; the split here carries a one-unit adjustment on wind so the three reconcile to that published total. Biomass covers wood and wood waste, black liquor, landfill gas, sludge waste, agricultural byproducts and biogenic municipal solid waste. Other fossil gas is blast furnace gas, gaseous propane and other manufactured waste gases; Other is hydrogen, non-biogenic municipal solid waste, batteries, purchased steam, sulfur and tire-derived fuel. One definitional seam is worth knowing: EIA-860 files gaseous propane under petroleum products, while Table 1.1 files it under other fossil gas, so the same fuel sits in the Petroleum slice on the capacity chart and the Other fossil gas slice on the generation chart. Only one 2.3 MW plant is affected.
Share of utility-scale electricity generated, by source
EIA preliminary data
Petroleum units are peakers and backup. They sit idle most hours because fuel is expensive, then start for the evening peak, for winter cold snaps when gas is constrained, or when another unit trips. The result is the spikiest and lowest profile of any source on this site.
Method: this is a modeled profile, not metered data. The 24-hour mean of 10.3% is the implied annual capacity factor, calculated as 2025 generation from EIA Electric Power Monthly Table 1.1 divided by the nameplate capacity of the active fleet on this page multiplied by 8,760 hours. EIA’s own published capacity factors use net summer capacity as the denominator and therefore run higher. The hourly shape applies the documented operating behaviour of this technology to that mean and is indicative rather than measured; metered hourly output would come from the EIA Hourly Electric Grid Monitor, which is not yet wired into this page.
| # | Plant | Type | State | Nearest city | Operator | Status | Capacity | Online |
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Most petroleum capacity is reciprocating diesel engines and oil-fired combustion turbines used for backup and peaking, and are widespread in Alaska, Hawaii, Puerto Rico and remote grids where other fuels are hard to deliver. Many sit on standby.
A shrinking set of large oil-fired steam turbine plants, mostly in the Northeast and on island grids, kept mainly for reliability and winter peaks when gas is constrained; among them are the biggest plants on this page (Wyman, Wagner, Kahe).
Petroleum is a small, mostly standby slice of US power at roughly 24 GW of active and standby capacity. This page shows only plants whose primary fuel is petroleum; the natural gas plants (including dual-fuel gas sites) are excluded and live on their own page.
Any utility-scale plant (1 MW or larger) in EIA-860 (2025 early release) with at least one generator whose primary energy source is a petroleum liquid or petroleum coke, namely distillate/diesel (DFO), residual fuel oil (RFO), kerosene (KER), jet fuel (JF), waste oil (WO) or petroleum coke (PC), aggregated to the EIA plant. That yields 982 plants, typed by prime mover.
No. Any plant that has a natural-gas-primary generator is treated as a natural gas plant and appears only on the Natural Gas page, including dual-fuel sites that can burn both gas and oil. This page lists only plants whose primary fuel is petroleum, so the two lists do not overlap.
Petroleum units are mostly backup and peaking capacity and are expensive to run, so they sit idle most of the year and start only during emergencies, extreme demand, or fuel shortages. Hundreds are therefore classified standby rather than actively operating.
They cluster in places without easy access to gas pipelines or large grids: Alaska, Hawaii, Puerto Rico and other islands rely on diesel engines, while the Northeast keeps large oil-fired steam units for winter reliability.
About 21 GW of active and standby capacity, a small share of US generation, and shrinking as older oil units retire. Most of it is rarely run.
It is the EIA-860 2025 early release (Schedules 2 and 3). EIA notes the early release is not fully edited and may withhold a few plants pending validation.
Petroleum is the website’s clearest example of capacity that exists to be held in reserve rather than run. Standby plants nearly rival active ones, and the geography explains why. Diesel engines and oil turbines concentrate where pipelines and large grids do not reach, in Alaska, Hawaii, Puerto Rico and remote communities. They are joined by a set of large oil-fired steam plants in the Northeast, kept for the coldest winter days, when gas is diverted to home heating.
Oil-fired power is expensive to run, so operators avoid it whenever cheaper sources can do the job; its advantage is that fuel can be stored on-site in tanks, independent of any network. That makes it the ultimate insurance policy. It is idle most of the year, invaluable during the rare hours of crisis. As batteries take over more of that reserve role, the petroleum fleet is slowly sliding from standby toward retirement, a transition visible in the large share of decommissioned plants on the map. We explore this reserve logic in The Power Plants That Almost Never Run.