Where Connecticut Gets Its Electricity
Net generation by source · 12-month average, September 2025 – August 2026.
Generation mix
| Source | Share | Generation |
|---|---|---|
| Natural gas | 56.2% | 25,672 GWh |
| Coal | 0.0% | 0 GWh |
| Nuclear | 37.2% | 16,999 GWh |
| Wind | 0.0% | 11 GWh |
| Solar | 1.8% | 828 GWh |
| Hydro | 0.6% | 258 GWh |
| Other | 4.2% | 1,921 GWh |
45.7 TWh generated over the 12 months to August 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 1,977 GWh that way. Counting it on both sides of the ratio takes solar from 1.8% to 5.9%.
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 | 3.7% | 40.9% | Natural gas 56.2% |
| U.S. average | 25.4% | 43.0% | Natural gas 40.9% |
| New York | 29.0% | 49.5% | Natural gas |
| Massachusetts | 23.9% | 23.9% | Natural gas |
| Rhode Island | 12.2% | 12.2% | Natural gas |
Connecticut's generation mix in context
Natural gas supplied 56.2% of Connecticut's electricity generation in the trailing twelve months to August 2026, the largest source by far. Nuclear power accounted for 37.2%, making it the second-largest contributor. Together, these two sources provided most of the state's electricity. Renewable sources generated 3.7% of the total, placing Connecticut lowest among the 50 states and DC with generation data. Carbon-free generation—renewables plus nuclear—reached 40.9% of the mix.
Solar made up 1.8% of generation from utility-scale facilities alone, and 5.9% when rooftop solar installations were included in the calculation, ranking 38th among the states. Hydro contributed 0.6%, while other sources, a category holding geothermal, biomass, and other fuels, accounted for 4.2%. Coal generation was zero.
The generation mix has shifted sharply since 2001. Gas surged from 13.4% in 2001 to 56.2% in 2025, while nuclear declined from 50.6% to 38.4% over the same period. Coal fell from 12.3% to nothing. A large share of other fuels, which stood at 22.8% in 2001, shrank to 2.9% in 2025. The renewable share remained essentially flat at 3.9% in 2001 and 3.9% in 2025. All three bordering states—New York, Massachusetts, and Rhode Island—generated higher renewable shares than Connecticut, at 29%, 23.9%, and 12.2% respectively. Nationally, natural gas was also the largest source at 40.9%, but renewables supplied 25.4% of electricity, far exceeding Connecticut's 3.7%.
Written from the EIA figures on this page, covering data through August 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 August 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.