LEARN / REINDUSTRIALIZATION

The Generation Mix

What a country has installed and what it actually generates are different distributions, and the gap between them is capacity factor. Coal holds 14 percent of American generating capacity and produces 17 percent of the electricity. Renewables hold a third of capacity and produce considerably less than a third.

Key points

Natural gas held about 40 percent of both capacity and generation in 2025, the one source where the two shares align.
Coal held 14 percent of capacity and produced about 17 percent of utility-scale generation.
Renewables reached 33.2 percent of utility-scale capacity, while wind and solar together produced 17 percent of utility-scale generation.
Dispatchable sources, natural gas, coal and nuclear, accounted for 75 percent of utility-scale generation.
Most published mix figures cover utility-scale plants only, which excludes rooftop solar and changes the totals.

Two different distributions

A generation mix can be stated two ways and the two do not agree. Installed capacity describes what exists, measured in megawatts. Generation describes what was produced, measured in megawatt-hours. A source with a high capacity factor produces a larger share of the electricity than its share of the capacity, and a source with a low one produces less.

Data14% capacity → 17% generation
Coal at the end of 2025: 14 percent of U.S. electricity generation capacity, about 17 percent of total utility-scale electricity generation. Natural gas held 40 percent of capacity and 40 percent of generation. Renewables reached 33.2 percent of utility-scale capacity while wind and solar produced 17 percent of utility-scale generation. Source: U.S. Energy Information Administration.

Series and provenance

Agency: U.S. Energy Information Administration
Program: Electric Power Monthly and Electricity Explained
Series: Generating capacity and net generation by source
Measure: U.S. electricity capacity share against generation share
Units: Percent of capacity; percent of net generation
Adjustment: Utility-scale plants of 1 MW and above unless stated
Period: Calendar year 2025
Latest: Coal 14 percent of capacity and about 17 percent of generation; natural gas 40 and 40; renewables 33.2 percent of utility-scale capacity; wind and solar 17 percent of utility-scale generation, 19 percent including small-scale solar; dispatchable sources 75 percent of generation
Source tier: Primary
Retrieved: August 9, 2026

Capacity share and generation share are different distributions separated by capacity factor. Most published figures cover utility-scale plants only; EIA estimates small-scale solar separately, and including it changes the wind and solar share by about two percentage points.

Open the source

Read across those pairs and the mix becomes legible. Coal overperforms its capacity share because coal units run when dispatched. Gas matches, because the fleet contains both baseload combined cycle plants and peaking units that run rarely, and the two average out. Wind and solar underperform their capacity share, because output follows conditions rather than instruction.

Dispatchability

EIA groups natural gas, coal and nuclear as dispatchable, meaning they can be operated on instruction and can run as baseload units. Together they accounted for 75 percent of utility-scale generation in 2025, a share EIA expects to fall to about 72 percent by 2027 as the combined wind and solar share rises from roughly 18 to 21 percent.

That transition is the substance of most current reliability argument. The share of electricity coming from resources that produce when instructed is declining slowly, while the share coming from resources that produce when conditions permit is rising. Whether the resulting system is adequate depends on storage, transmission, demand flexibility and the accreditation methods used to plan around all three.

Measurement noteMost published mix figures cover utility-scale plants, defined by EIA as those with at least one megawatt of generating capacity. Small-scale solar, mainly rooftop, is estimated separately. Including it raises the 2025 wind and solar share from 17 percent of utility-scale generation to 19 percent of total net generation. A comparison between one figure that includes small-scale solar and one that does not is not a comparison.

Why the mix matters for industrial capacity

An industrial facility running continuously draws in every hour, including the ones when weather-dependent output is low. The relevant question for such a site is not the annual share of clean generation in its region but what serves load during the hardest hours, which is a question about dispatchable capacity, storage duration and imports rather than about annual percentages.

Institute analysisAnnual mix percentages answer a question about emissions and investment. They do not answer the question a manufacturer is asking, which concerns availability in specific hours. A region can hold a high annual renewable share and a tight position during winter mornings, and the annual figure gives no warning of it.

Common misconceptions

That capacity share describes the mix. Capacity is what exists; generation is what was produced. The two differ by capacity factor and can point in different directions.

That renewables at a third of capacity means a third of the electricity. Renewables reached 33.2 percent of utility-scale capacity in 2025 while wind and solar produced 17 percent of utility-scale generation.

That all published shares are comparable. Utility-scale figures exclude rooftop solar, which EIA estimates separately. Whether a figure includes it changes the answer by around two percentage points.

What the evidence says, and where it is contested

ContestedWhether the declining dispatchable share represents a reliability problem is genuinely disputed. One position holds that the metric that matters is not the share of dispatchable generation but whether the portfolio, including storage and transmission, can serve load in every hour, and that systems have operated reliably through the transition so far. A second holds that reliability has been maintained partly by delaying retirements and by drawing on neighbouring regions, and that both are finite. The disagreement concerns how much margin remains before the transition becomes binding, which is a forward-looking question that current operating experience cannot settle.

Related Institute research

Why Supply Is Not Keeping Pace
Why nameplate additions and accredited additions differ.

Firm Power and Why It Matters
What a system can count on in the hours that matter.

How Electricity Demand Is Measured
Energy, peak and load factor.

Sources

U.S. Energy Information Administration, Electricity generation, capacity, and sales in the United States. eia.gov
U.S. Energy Information Administration, Wind and solar generated a record 17% of U.S. electricity in 2025, March 2026. eia.gov
U.S. Energy Information Administration, Short-Term Energy Outlook. eia.gov
U.S. Energy Information Administration, Electric Power Monthly. eia.gov
North American Electric Reliability Corporation, 2025 Long-Term Reliability Assessment. nerc.com

Reference entry maintained by the Institute for American Manufacturing & Technology. Figures are drawn from primary sources and cited above. Where the Institute states a position rather than a finding, it is marked as such.