Where Connecticut Gets Its Electricity
Net generation by source · 12-month average, July 2025 – June 2026.
Generation mix
| Source | Share | Generation |
|---|---|---|
| Natural gas | 56.2% | 25,548 GWh |
| Coal | 0.0% | 0 GWh |
| Nuclear | 37.2% | 16,910 GWh |
| Wind | 0.0% | 11 GWh |
| Solar | 1.8% | 837 GWh |
| Hydro | 0.7% | 296 GWh |
| Other | 4.1% | 1,884 GWh |
45.5 TWh generated over the 12 months to June 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 1,921 GWh that way. Counting it on both sides of the ratio takes solar from 1.8% to 5.8%.
How the mix has shifted since 2001
| Source | 2001 | 2025 | Change |
|---|---|---|---|
| Natural gas | 13.4% | 56.2% | +42.8 pts |
| Coal | 12.3% | 0.0% | −12.3 pts |
| Nuclear | 50.6% | 38.4% | −12.2 pts |
| Wind | 0.0% | 0.0% | — |
| Solar | 0.0% | 1.7% | +1.7 pts |
| Hydro | 0.9% | 0.8% | −0.2 pts |
| Other | 22.8% | 2.9% | −19.9 pts |
Compared with the U.S. and nearby states
| Where | Renewable | Carbon-free | Largest source |
|---|---|---|---|
| Connecticut | 3.8% | 41.0% | Natural gas 56.2% |
| U.S. average | 25.2% | 42.9% | Natural gas 40.7% |
| New York | 29.1% | 49.7% | Natural gas |
| Massachusetts | 22.3% | 22.3% | Natural gas |
| Rhode Island | 11.6% | 11.6% | Natural gas |
Connecticut's generation mix in context
Natural gas supplied 55.7% of Connecticut's electricity generation since June 2025, more than any other source. Nuclear power provided 37.7%, the second-largest share. Together, these two sources accounted for over nine-tenths of generation. Solar made up 1.8% on a utility-scale basis, though when rooftop solar is counted the figure rises to 5.7%. Hydroelectric generation contributed 0.7%, while other sources, which include geothermal and biomass, made up 4.2%.
The state generated 3.7% of its electricity from renewable sources, ranking lowest among all states and the District of Columbia. Carbon-free generation, which includes nuclear along with renewables, reached 41.4%. This compares with a national renewable share of 24.9% and national carbon-free generation of 42.6%. Connecticut falls well below its bordering states on renewable energy: all three neighbours—New York, Massachusetts, and Rhode Island—generated higher renewable shares, at 29%, 21.2%, and 11.5% respectively.
The generation mix has shifted markedly since 2001. Natural gas surged 42.8 percentage points, from 13.4% in 2001 to 56.2% in 2025. Nuclear fell 12.2 points, from 50.6% to 38.4%. Coal, which provided 12.3% in 2001, disappeared entirely. Solar emerged over this span, reaching 1.7% in 2025 from nothing at the start. Hydroelectric declined slightly from 0.9% to 0.8%, and other sources shrank from 22.8% to 2.9%. Renewable generation as a share held steady at 3.9% across the two years, as solar's growth offset small declines in other renewable sources.
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 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.