Connecticut Utility Cost Calculator

Supply and delivery are separate

Energy-only suppliers delivered 49% of Connecticut’s retail electricity in 2024 to about 365,000 accounts: the wires belong to Connecticut Light & Power or United Illuminating, while the supply portion of a bill can come from the utility or from a competitive supplier such as Constellation NewEnergy, which ranked second in household sales. The Public Utilities Regulatory Authority regulates the two utilities.

Residential prices moved down this summer — 24.16¢ per kWh in July 2026 against 27.60¢ a year earlier — while the 12-month average of 27.99¢ still carries the costlier winter months.

Oil country, gas country

Connecticut heats with fuel oil (39% of homes) almost as often as with natural gas (36%). An oil-heated home burned 629 gallons a year in the 2020 survey; at the $5.546 per gallon EIA logged in the last week of the 2025–26 season, that is a large bill concentrated in winter. Gas accounts average about 821 therms a year, but EIA lists the 2025 residential gas price as not available, so the calculator falls back to 2024’s — check your own bill.

Nuclear power, few smart meters

The Millstone nuclear station supplied 38% of the state’s 2024 generation and gas plants 58%; Connecticut generated about 1.6 times the electricity it sold to its own customers. Unlike most states, it has few smart meters — only about 21% of residential meters were advanced (AMI) meters in 2024. Help with heating bills is available through the Department of Social Services.