How is the average electricity rate calculated?

Residential revenue divided by residential kWh sold, from EIA Form 861M. The 12-month average is weighted by kWh sold each month.

How is the average electric bill calculated?

Residential revenue divided by the number of residential customers in the state for that month.

Do solar estimates include the federal tax credit?

No. The residential clean energy credit (25D) does not apply to expenditures made after 31 December 2025.

How we calculate

Electricity prices

Average price (cents per kWh) = utility revenue ÷ kWh sold, using EIA monthly data (Form EIA-861M). The 12-month price is weighted by kWh sold in each month. Rank 1 is the most expensive of the 50 states plus DC.

Average bill and usage

Average monthly bill = residential revenue ÷ residential customers. Average usage = residential kWh sold ÷ customers. These are state averages, not a specific household.

Appliance costs

Daily kWh = watts × hours used ÷ 1,000 (the US Department of Energy method). Cost = kWh × the state's 12-month average residential price. A month is 30.42 days.

Solar estimates

Production per kW comes from NREL PVWatts (version 8) for the state's largest city, with a fixed roof-mount array, 20° tilt, south-facing, standard modules and 14% system losses.

System size = annual household use ÷ kWh per kW, rounded up to whole 400 W panels. Cost = size × $2.57 per watt. Savings each year = the lower of production and household use × the electricity price. Production falls 0.5% a year; prices rise 0% a year. Payback is the year cumulative savings pass the cost, over 25 years. No federal tax credit is included: the residential clean energy credit (25D) does not apply to systems installed after 31 December 2025.

EV charging

Example efficiency: 30 kWh per 100 miles. Change it in the calculator to match your vehicle.

Last updated 9 November 2026 · By the SolarOwnersHub.com Editorial Team