Model the value of stored energy
Estimate annual bill savings and simple payback for a home battery using your usable capacity, cycling, tariffs and efficiency.
Method
Annual saving = energy delivered × import tariff − energy charged × export tariff. Simple payback = installed cost ÷ annual saving.
A 10 kWh battery with 90% usable capacity, 250 cycles and 90% round-trip efficiency delivers about 2,025 kWh per year before degradation.
Use responsibly
This is a simple pre-tax cash model. It excludes degradation, finance, maintenance, dynamic prices, grid-service income and tariff changes. Results are not a quotation.
Last reviewed: 20 July 2026
Calculation and copy checked for this release.
