Data sources

Every number on this site comes from one of the sources below. Each appliance and car page lists its own.

Electricity rates

• EIA Electric Power Monthly, Table 5.6.A: average price of electricity to ultimate customers by end-use sector, by state. Latest month used: June 2026. Retrieved September 26, 2026.
• EIA Open Data API v2, route electricity/retail-sales, residential sector, monthly: used by our monthly refresh.
• EIA Form 861 annual retail sales, revenue and customers by state (via the Catalyst Cooperative PUDL open-data build): annual price history and the state ranking by number of residential customers.

Status: June 2026 values were transcribed from pages that republish EIA Table 5.6.A (the build container could not reach eia.gov). June 2025 values are derived from the stated 12-month change. Run bin/update_rates.php with an EIA API key to replace them with values read directly from the EIA API.

Appliance power

• Virginia Cooperative Extension: space heater, ceiling fan, whole-house fan, dehumidifier, electric blanket, refrigerator, microwave, dishwasher, coffee maker, toaster, toaster oven, washing machine, clothes dryer, clothes iron, tv, desktop computer, laptop, computer monitor, electric water heater, hair dryer, well pump, vacuum cleaner.
• Penn State EGEE 102: space heater, ceiling fan, whole-house fan, dehumidifier, electric blanket, refrigerator, microwave, dishwasher, coffee maker, toaster, toaster oven, washing machine, clothes dryer, clothes iron, tv, desktop computer, laptop, computer monitor, electric water heater, hair dryer, well pump, vacuum cleaner.
• ENERGY STAR: refrigerator.
• U.S. Department of Energy: refrigerator.
• ENERGY STAR: chest freezer, upright freezer.
• Xcel Energy: electric oven.
• Southern California Edison: coffee maker, washing machine.

Electric cars

EPA combined efficiency ratings (kWh per 100 miles), range and battery capacity. The official source is fueleconomy.gov; each car page lists the pages we took its figures from. 24 cars are published.

Gasoline

AAA, national average price of regular gasoline: $4.48 a gallon on September 24, 2026. Fallback: EIA weekly U.S. regular gasoline retail price (series EMM_EPMR_PTE_NUS_DPG).

Geography

Neighboring states are computed from U.S. Census Bureau cartographic boundary files. Climate regions follow the NOAA NCEI U.S. climate regions.

Not yet published

91 appliances and 49 cars are researched but waiting for a sourced wattage or efficiency figure. We add them as soon as a source is confirmed.