Battery ROI Calculator

Time-of-use arbitrage savings for a standalone or solar-paired battery — shows the payback from rate-shifting alone.

This calculates dollar savings from shifting energy use to off-peak hours. Want backup runtime during an outage instead? See the Battery Backup Calculator.

Heads up: the 30% federal battery storage tax credit expired for systems placed in service after December 31, 2025. This calculator defaults to no federal credit. Estimates are for general planning only, not a quote.

This tool provides a planning estimate based on the assumptions shown below the results — it is not a quote, and actual costs and savings will vary by installer, local rates, and your specific home.

Your state

Sets the off-peak rate below to your state's average (EIA, April 2026) as a flat-rate baseline — peak rate still needs your actual time-of-use rate, since that premium varies by utility, not just by state.

This system was placed in service on or before Dec 31, 2025 (federal credit still applies)

Battery system cost (installed)

Usable capacity

kWh

Peak rate

Off-peak rate

Find both on your time-of-use rate plan.

Full cycles per week

Enter your numbers to see your battery's arbitrage payback.

How this calculator works

Each cycle shifts usable capacity from off-peak to peak hours, valued at the difference between your two rates, derated by a 90% round-trip efficiency (typical for lithium-based home batteries).

If you flag the system as a 2025 install, cost applies the (now-expired) 30% federal Residential Clean Energy Credit; otherwise assumes no federal credit, since it expired for property placed in service after 2025-12-31. Payback is based on arbitrage savings alone.

Source: DOE Office of Electricity, Energy Storage; IRS Residential Clean Energy Credit, last updated 2026-07-10.