What a battery costs
Installed home batteries run roughly $700-$1,200 per usable kWh before incentives. Compare quotes on $/kWh, not sticker price.
Incentives and tax rules
The 30% residential credit (IRC 25D) ended for expenditures after 2025; some states and utilities still offer rebates. Verify current law on DSIRE and with a tax professional.
Payback screening
Annual savings equal usable kWh times cycles per year times savings per kWh minus upkeep. Divide net cost by annual savings for payback years.
Formulas used
Annual savings
usable kWh x cycles/year x $/kWh - upkeep
Payback
net cost / annual savings
Worked examples
13.5 kWh, 300 cycles, 25c spread
13.5 x 300 x 0.25 - 100 = $912/year; $9,000 / 912 = 9.9 years.
Common questions
Are home batteries worth it?
They pencil out fastest with wide peak/off-peak spreads, demand charges, or frequent outages; flat-rate grids pay back slowly.
What is a good $/kWh for batteries?
Compare lifetime $/kWh (price divided by kWh times warranted cycles), not upfront $/kWh.
Sources
- DSIRE Incentive Database N.C. Clean Energy Technology Center
- Energy Saver: Battery Storage U.S. Department of Energy