Where Illinois Gets Its Electricity
Net generation by source · 12-month average, July 2025 – June 2026.
Generation mix
| Source | Share | Generation |
|---|---|---|
| Natural gas | 17.2% | 33,429 GWh |
| Coal | 15.0% | 29,025 GWh |
| Nuclear | 49.7% | 96,410 GWh |
| Wind | 13.4% | 25,995 GWh |
| Solar | 4.2% | 8,204 GWh |
| Hydro | 0.0% | 31 GWh |
| Other | 0.4% | 772 GWh |
193.9 TWh generated over the 12 months to June 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 2,625 GWh that way. Counting it on both sides of the ratio takes solar from 4.2% to 5.5%.
How the mix has shifted since 2001
| Source | 2001 | 2025 | Change |
|---|---|---|---|
| Natural gas | 2.6% | 16.8% | +14.3 pts |
| Coal | 44.4% | 16.0% | −28.4 pts |
| Nuclear | 51.5% | 50.5% | −1.0 pts |
| Wind | 0.0% | 12.9% | +12.9 pts |
| Solar | 0.0% | 3.4% | +3.4 pts |
| Hydro | 0.1% | 0.0% | −0.1 pts |
| Other | 1.4% | 0.4% | −1.1 pts |
Compared with the U.S. and nearby states
Illinois's generation mix in context
Nuclear generation supplied 49.7% of Illinois' electricity in the twelve months from June 2025 to May 2026, making it by far the largest source. Gas and coal together accounted for nearly one-third of generation, while wind provided 13.3%. Solar contributed 4.0% of utility-scale generation, or 5.2% when rooftop solar is included. Renewables as a whole made up 17.4% of the state's mix, placing it 27th among the 51 states and DC with generation data. Carbon-free sources together supplied 67.1%, well above the national average of 42.6%.
The generation mix has shifted dramatically since 2001. Coal's share collapsed from 44.4% to 16.0% in 2025, while gas expanded from 2.6% to 16.8% over the same span. Wind grew from nothing to 12.9% in 2025, and solar climbed from zero to 3.4%. Nuclear has remained the backbone of the state's electricity, slipping only slightly from 51.5% in 2001 to 50.5% in 2025. Renewables overall rose from 0.5% in 2001 to 16.4% in 2025.
Illinois' renewable share of 17.4% lies 7.5 percentage points below the national figure of 24.9%. Among its five bordering states, only Iowa generates more renewable electricity, with 61.5% of its mix from wind and other clean sources. Indiana, Wisconsin, Missouri and Kentucky all have lower renewable shares than Illinois, ranging from 8.6% to 17.3%.
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 June 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.