FullCalculator

Solar Battery Storage Payback Calculator

Time-of-Use Arbitrage

Calculate savings from charging during off-peak and discharging during peak hours

Solar + Battery

Battery paired with solar for self-consumption maximization

Formula

Daily Savings = Usable Capacity × Cycles × (Peak Rate − Off-Peak / Efficiency); Payback = Net Cost / Annual Savings; Net Cost = Battery Cost × (1 − ITC Rate)

Frequently Asked Questions

Is a home battery worth the investment?
It depends on your utility rate structure. If you have time-of-use rates with a large peak/off-peak spread ($0.20+), batteries can pay back in 5-8 years. With flat rates, the financial case is weaker, but backup power during outages adds value that's hard to quantify.
How long do home batteries last?
Most home batteries (Tesla Powerwall, Enphase, etc.) are warrantied for 10-15 years at 70-80% capacity. Real-world data suggests lithium-ion home batteries can last 15-20 years with proper management. They typically lose 2-3% capacity per year.

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