Power Bill Facts

Methodology

This page sets out every calculation on the site. Nothing is estimated or modelled: each figure is either copied from a U.S. Energy Information Administration (EIA) file or derived from one by the arithmetic below.

Average price, bill and use

average price (¢ per kWh) = revenue ÷ sales × 100

EIA collects revenue in thousands of dollars and sales in megawatthours for each utility, state, sector and year. Dividing one by the other gives the average revenue per kilowatthour, which EIA publishes as the "average price". It is not a tariff rate. It folds together fixed monthly charges, fuel and other riders and every rate schedule in the sector, weighted by how much customers on each schedule used. EIA's form instructions define what a respondent counts as revenue.

average monthly bill = residential revenue ÷ residential customers ÷ 12
average monthly use = residential sales ÷ residential customers ÷ 12

These follow EIA's own average-bill tables. For a single month the division by twelve is dropped. Customer counts are as each utility reports them on the form; a customer is a meter or account, not a person.

Bundled, energy-only and delivery-only service

Form EIA-861 separates bundled service (parts A and D of the sales schedule, where one respondent bills the whole service) from energy-only service (part B) and delivery-only service (part C), which arise where customers can buy energy from a retail supplier. Energy-only or delivery-only revenue covers part of a bill, so dividing it by sales understates the price. On this site:

State and US figures

State and US averages by year and month are EIA's own, from the Form EIA-861M sales and revenue workbook (through July 2026). Final years in that workbook are benchmarked by EIA to the annual Form EIA-861 census; recent months and the latest year are marked preliminary and are revised. State reliability totals are EIA's "any standard" figures from the Form EIA-861 reliability file. This site does not add up utility rows to make a state figure.

Where a page shows a median (for a state, a county's utilities, an ownership type or the country), it is computed here across utility filings in the final 2024 file, each filing counting once regardless of size. Medians and EIA's customer-weighted averages answer different questions and are labelled each time.

Thresholds

The price dial

The dial on utility, state and ownership pages shows position in the national distribution of 1,230 utilities' average residential prices for 2024. The knob sits at the share of utilities with that price or lower; the ends are labelled with the 1st and 99th percentile prices. Reference ticks (state average, US average) are placed the same way. Because most utilities are small and the largest tend to have higher prices, the customer-weighted US average sits well above the median utility.

Reliability

SAIDI is the average minutes of sustained interruption per customer over the year; SAIFI is the average number of sustained interruptions per customer; CAIDI is SAIDI divided by SAIFI. Utilities report them either under the IEEE 1366 standard or under another method, with and without major event days. The site shows both versions as reported and states the method. Figures from different methods are shown side by side with that warning and are never combined into one number. For a utility in several states, the utility-level figure is the customer-weighted mean of its state rows that use the same method as its largest state.

Trends and the early release

Year-by-year figures use the final Form EIA-861 file for each year from 2013. Changes are nominal, not adjusted for inflation. EIA's early release for 2025 is described by the agency as not fully edited and inappropriate for aggregation. It is shown as a marked row on the utility's own page and nowhere else.

Utilities are tracked by EIA utility number. Mergers, renamings and moves between the full and short form appear as breaks in a series; nothing is spliced.

Counties

County pages come from the Form EIA-861 service territory file, where each utility lists the counties it serves. EIA publishes no customers, prices or outages by county. Every figure on a county page is therefore the utility's figure for its whole operation in that state. Territories overlap, and a utility may cover only a small part of a county. Connecticut's counties are listed as EIA names them, although the Census Bureau now reports Connecticut by planning region, so no population is shown there.

Generation mix

The stacked bar sums Form EIA-923 net generation for 2025 across plants whose operator is the utility, grouped as coal, natural gas, nuclear, hydro (pumped storage excluded), wind, solar, petroleum and other. It describes what the utility's plants generated. It does not describe the power delivered to its customers, which also depends on wholesale purchases, sales to other utilities and shares in plants operated by others.

Update cycle

The site rebuilds daily. Closed years are read from compact snapshots of the final EIA files kept with the site's code; the newest annual file, the monthly workbook and the monthly utility sample are downloaded at each build. Every page footer carries the date the data runs to.