Where Illinois Gets Its Electricity
Net generation by source · 12-month average, June 2025 – May 2026.
Generation mix
| Source | Share | Generation |
|---|---|---|
| Natural gas | 17.4% | 33,705 GWh |
| Coal | 15.3% | 29,641 GWh |
| Nuclear | 49.7% | 96,318 GWh |
| Wind | 13.3% | 25,686 GWh |
| Solar | 4.0% | 7,680 GWh |
| Hydro | 0.0% | 31 GWh |
| Other | 0.4% | 768 GWh |
193.8 TWh generated over the 12 months to May 2026. Shares are of net generation within Illinois, which is not the same as what the state consumes — power crosses state lines.
Counting rooftop solar
EIA reports small-scale solar — mostly rooftop panels on homes and businesses — separately, and leaves it out of the state generation total that the mix above is a share of. Illinois generated 2,537 GWh that way. Counting it on both sides of the ratio takes solar from 4.0% to 5.2%.
How the mix has shifted since 2016
| Source | 2016 | 2025 | Change |
|---|---|---|---|
| Natural gas | 9.3% | 16.8% | +7.5 pts |
| Coal | 31.7% | 16.0% | −15.7 pts |
| Nuclear | 52.6% | 50.5% | −2.2 pts |
| Wind | 5.7% | 12.9% | +7.2 pts |
| Solar | 0.0% | 3.4% | +3.3 pts |
| Hydro | 0.1% | 0.0% | −0.1 pts |
| Other | 0.5% | 0.4% | −0.2 pts |
Compared with the U.S. and nearby states
Illinois's generation mix in context
Nuclear power supplied 49.7% of Illinois's electricity generation between June 2025 and May 2026, making it the dominant source. Gas accounted for 17.4%, coal 15.3%, and wind 13.3%. Solar made up 4% of utility-scale generation, or 5.2% when rooftop solar is included. These figures mean Illinois generated 67.1% of its electricity from carbon-free sources, well above the national average of 42.6%. Renewables—wind, solar, hydro, and the renewable fraction of other sources—totaled 17.4% of generation, ranking 27th among the 51 states and DC.
Over the past decade, Illinois's generation mix shifted substantially. Coal collapsed from 31.7% in 2016 to 16% in 2025, a loss of 15.7 percentage points. Nuclear declined slightly from 52.6% to 50.5%. Wind expanded from 5.7% to 12.9%, and solar grew from zero to 3.4%, driving the renewable share up from 6% to 16.4%. Gas increased from 9.3% to 16.8%, partially offsetting the gains from renewable growth.
Compared with the national mix, Illinois relies much less on gas—17.4% against 40.8% nationally—and far more on nuclear. It generates less renewable energy than the country as a whole, which stood at 24.9%. Among its neighbours, only Iowa exceeds Illinois's renewable share at 61.5%. Indiana, Wisconsin, Missouri, and Kentucky all generate smaller shares of renewables, though Indiana and Missouri depend more on coal.
Written from the EIA figures on this page, covering data through May 2026.
Frequently asked questions
›What percentage of Illinois's electricity comes from renewable energy?
›What percentage of Illinois's power comes from solar?
›Where does Illinois get most of its electricity?
›Does Illinois still burn coal for electricity?
›Is Illinois getting greener?
How this is measured
Figures are net generation reported to the U.S. Energy Information Administration for all sectors — utilities, independent power producers, and industrial and commercial plants that generate their own power. Shares are of the 12 months to May 2026, rather than a single month, because generation is strongly seasonal: solar peaks in summer and hydro with the spring melt, so one month says more about the weather than about the grid.
“Other” is the reported total minus the six named sources, so the shares add to exactly 100%. It holds geothermal, biomass, petroleum, other gases, and pumped storage — the last of which consumes more electricity than it returns, and so can be negative. Geothermal and biomass are renewable, which is why the renewable share above is slightly larger than wind, solar and hydro added together.
This is generation, not consumption. Electricity crosses state lines freely, so a state can generate more than it uses or rely on imports for a large part of its supply; neither shows up here.