Where Connecticut Gets Its Electricity
Net generation by source · 12-month average, June 2025 – May 2026.
Generation mix
| Source | Share | Generation |
|---|---|---|
| Natural gas | 55.7% | 25,345 GWh |
| Coal | 0.0% | 0 GWh |
| Nuclear | 37.7% | 17,165 GWh |
| Wind | 0.0% | 11 GWh |
| Solar | 1.8% | 818 GWh |
| Hydro | 0.7% | 302 GWh |
| Other | 4.2% | 1,891 GWh |
45.5 TWh generated over the 12 months to May 2026. Shares are of net generation within Connecticut, 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. Connecticut generated 1,875 GWh that way. Counting it on both sides of the ratio takes solar from 1.8% to 5.7%.
How the mix has shifted since 2016
| Source | 2016 | 2025 | Change |
|---|---|---|---|
| Natural gas | 49.2% | 56.2% | +7.0 pts |
| Coal | 0.5% | 0.0% | −0.5 pts |
| Nuclear | 45.4% | 38.4% | −7.1 pts |
| Wind | 0.0% | 0.0% | — |
| Solar | 0.1% | 1.7% | +1.7 pts |
| Hydro | 0.6% | 0.8% | +0.2 pts |
| Other | 4.2% | 2.9% | −1.3 pts |
Compared with the U.S. and nearby states
| Where | Renewable | Carbon-free | Largest source |
|---|---|---|---|
| Connecticut | 3.7% | 41.4% | Natural gas 55.7% |
| U.S. average | 24.9% | 42.6% | Natural gas 40.8% |
| New York | 29.0% | 49.5% | Natural gas |
| Massachusetts | 21.2% | 21.2% | Natural gas |
| Rhode Island | 11.5% | 11.5% | Natural gas |
Connecticut's generation mix in context
Natural gas supplied 55.7% of Connecticut's electricity generation in the trailing twelve months to May 2026, making it the largest source. Nuclear power generated 37.7% of the state's total, while renewables accounted for 3.7% of generation. The solar share was 1.8% when counting utility-scale facilities alone, but 5.7% when rooftop solar is included in the total.
Over the past decade, natural gas generation grew by 7 percentage points, rising from 49.2% in 2016 to 56.2% in 2025. Nuclear fell by the same amount, declining from 45.4% to 38.4%. Solar expanded significantly, increasing from 0.1% to 1.7%. Coal, which represented 0.5% in 2016, is no longer part of the generation mix. Renewable generation overall rose modestly from 3.1% in 2016 to 3.9% in 2025, an increase of 0.8 percentage points.
Connecticut's renewable share ranks last among all 51 states and DC with generation data. Its solar share ranks 38th. Both neighbours and the national average show higher renewable generation: New York generates 29.0% from renewables, Massachusetts 21.2%, and Rhode Island 11.5%, while the national renewable share stands at 24.9%. Nationally, natural gas also leads at 40.8%, but renewables supply nearly seven times the share they do in Connecticut.
Written from the EIA figures on this page, covering data through May 2026.
Frequently asked questions
›What percentage of Connecticut's electricity comes from renewable energy?
›What percentage of Connecticut's power comes from solar?
›Where does Connecticut get most of its electricity?
›Does Connecticut still burn coal for electricity?
›Is Connecticut 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.