Data · Methodology · Version 1
How the Electricity Price Index Is Built
Every figure in the Geostellar Residential Electricity Price Index traces to a public federal dataset, a stated metric, and a stated time window. This page documents the source, the exact definition, how we aggregate it, when it updates, and what it cannot tell you.
Latest data period: · Snapshot generated
Source data
The index is computed from U.S. Energy Information Administration (EIA), Electricity retail sales — average price by state. We query the EIA Open Data API v2 electricity retail-sales endpoint for the monthly residential (sector RES) average price, in cents per kilowatt-hour, for every state and DC, back to January 2001. We use no proprietary or private-market data.
Exact metric definition
The metric: Average residential retail price of electricity published by the EIA for the state, in cents per kilowatt-hour — a statewide monthly average, not a personalized utility tariff or the rate any single household pays.
Prices are taken exactly as EIA publishes them per state per month; we round to the source’s two-decimal precision and never add precision the source does not provide.
Derived figures
- National average (month) = unweighted mean of the state residential averages reporting that month — a cross-state benchmark, not a sales-weighted national rate.
- Year-over-year change = (latest month ÷ same month one year earlier − 1) × 100. Where a state lacks the 12-months-prior period, we compare against the earliest available month and label the change “since <month>.”
- vs. national = (state average ÷ national average − 1) × 100, both for the latest period.
- Estimated annual bill = state rate × 10,500 kWh, the approximate U.S. average annual residential consumption — an illustration of the rate’s dollar impact, not a billed amount.
Update cadence and data lag
We refresh the snapshot monthly, after EIA publishes a new complete month. EIA publishes state retail-price data on a lag of roughly two to three months; the latest period shown reflects that lag. In practice the newest period shown is about three months behind the calendar: the April 2026 period is the latest complete month available as of this snapshot, which spans 304 monthly periods from January 2001.
Limitations — read before citing
- Not your personal rate. These are statewide averages; your utility, rate plan, and usage tier determine what you actually pay.
- Average of all residential customers. The figure blends every utility and rate class in a state, so it can mask wide differences between territories within the same state.
- Unweighted national benchmark. Our national line is a simple mean of state averages; it is not EIA’s population- or sales-weighted national figure.
- Retail price only. The series is the retail price of grid electricity — it does not model net-metering credits, demand charges, or fixed monthly fees, which affect real solar economics.
Frequently asked questions
Is this the rate I personally pay?
No. The index reports the EIA-published state residential average retail price of electricity — a statewide monthly average across all residential customers and utilities. Your own rate depends on your specific utility, rate plan, tier, and time-of-use schedule, and can differ substantially from the state average.
Where does the data come from?
Every figure is computed from U.S. Energy Information Administration (EIA), Electricity retail sales — average price by state, the U.S. Energy Information Administration's public electricity retail-sales series, queried from https://api.eia.gov/v2/electricity/retail-sales/data/. We use no proprietary or private data.
Why is the latest month a few months old?
EIA publishes state retail-price data on a lag of roughly two to three months; the latest period shown reflects that lag. We publish the newest complete month once EIA releases it, so the index runs on roughly an M-3 schedule rather than showing the current calendar month.
Why does this matter for solar?
Your electricity rate is the single biggest driver of how much a solar system saves and how fast it pays back: savings are the kilowatt-hours you no longer buy from the grid multiplied by their price. A higher rate — or a rising one — shortens payback. That is why every state page links to a solar-savings estimate pre-filled with the state's rate.
How is the national average computed?
The national figure shown here is the unweighted mean of the state averages for each month — a simple cross-state benchmark, not a customer- or sales-weighted national rate. EIA also publishes an official national residential average; use that where a population-weighted figure is required.
Can I reuse these figures or the CSV files?
Yes. The tables and CSV downloads are free to reuse with attribution to Geostellar and a link to the page you drew from. A suggested citation appears in the "Use this data" block on every data page.
Changelog
- v1 — July 2026. Initial release: national trend, 51 state pages, 304 monthly periods through April 2026, CSV downloads, and this methodology.
Corrections
If a figure does not reconcile with the EIA source, email corrections@geostellar.com with the page URL and the period in question. Confirmed errors are corrected in the next snapshot and noted in the changelog above.