Solar panels
Do solar panels pay for themselves?
System size, install cost and payback period from your state's electricity price and actual solar resource.
Pays back inside 10 years in 13 of 51 states →
EV vs gas
Is an EV cheaper to run than gas?
Charging versus fuel, including the charging losses and public fast-charging costs most comparisons quietly omit.
Cheaper to fuel than gas in 51 of 51 states →
Heat pump vs furnace
Is a heat pump cheaper than gas heating?
Running costs with efficiency adjusted for your actual climate, instead of one flattering figure applied nationwide.
Cheaper to run than gas in only 17 of 51 states →
Home battery
Does a home battery pay for itself?
What a battery actually earns on your bill, kept strictly separate from what backup power is worth to you.
Pays for itself in 0 of 51 states →
Why these numbers disagree with the brochure
Payback calculators are usually published by people selling the thing being calculated. The result is a set of predictable thumb on the scale: a flat efficiency figure applied to every climate, solar production quoted before real-world losses, battery savings counted twice, EV charging priced as though every kilowatt-hour comes from a cheap home tariff.
We model each of those honestly and show the workings on every page. Sometimes that produces a worse answer than you were hoping for — a heat pump costs more to run than gas across most of the cold north, and a home battery does not pay for itself anywhere on bill savings alone. Those are the findings, so those are what we publish.
None of it is an argument against buying. It is an argument for knowing the real number first, and for buying the thing for the reason it actually delivers.
Data vintage: Electricity: EIA Electric Power Monthly Table 5.6.B (residential, May 2026 YTD). Solar resource: PVGIS v5.3 (EU JRC), ERA5 2005-2023. Gasoline: AAA state averages. Natural gas: EIA residential by state. Heating degree days: NOAA CPC population-weighted normals. Retrieved 2026-08-03/04. Install costs, household usage, net-metering status, annual mileage, time-of-use spreads and outage hours remain estimates.