Home battery payback
7.5 kWh home battery payback example
This worked example shows how simple payback changes with installed cost, cycling, round-trip efficiency and the value of each shifted kWh.
Illustrative base case13.9 years simple payback
£5,125 installed cost · 0.75 cycles/day · 90% efficiency · 20p/kWh value spread
Low / base / high-benefit sensitivity
| Scenario | Cost | Cycles | Efficiency | Spread | Useful shifted energy | Annual value | Payback |
|---|---|---|---|---|---|---|---|
| Cautious | £6,150 | 0.50/day | 88% | 12p | 1,204 kWh | £145/yr | 42.5 yrs |
| Base | £5,125 | 0.75/day | 90% | 20p | 1,848 kWh | £370/yr | 13.9 yrs |
| High-use / wide spread | £4,356 | 0.90/day | 92% | 28p | 2,267 kWh | £635/yr | 6.9 yrs |
The installed cost is a worked-example assumption, not a current quote. Battery degradation, usable capacity, warranty limits, financing, export effects and real control behaviour are excluded from simple payback.