Solar decisions, backed by public data.
Free calculators, state-by-state cost and incentive data, and spec-based battery and power station comparisons — sourced from EIA, NREL, LBNL, DSIRE, state energy offices, and manufacturer specs.
Calculators
Solar Calculator
System size, cost, and payback for your state.
Generator Size Calculator
What size generator you actually need.
Battery Runtime Calculator
How long a battery can run your load.
Electricity Cost Calculator
What an appliance costs to run.
Featured
Is Solar Worth It in California?
Real cost, incentives, and a computed payback estimate.
Solar Lease vs. Buy vs. PPA
How the 2026 tax credit rules change the math.
EcoFlow vs. Jackery
Spec-by-spec, plus a real appliance runtime table.
Best Solar Battery for Home Backup
All published models ranked by GoSolarIndex Score.
Every number has a source
Every number on this site traces back to a real source — EIA, NREL, LBNL, IRS.gov, a state energy office, or a manufacturer's own spec sheet — shown on the page it appears on. See our methodology.