Battery Size & Payback Calculator
South West Tech — what a battery does for your bill, and when it pays for itself
— kWh battery recommended
| Overnight consumption covered | — |
| Backup runtime at 1.5 kW | — |
| Solar needed to charge it daily | — |
| Estimated rebate | — |
| Installed cost after rebate | — |
| Annual savings | — |
| Approximate payback | — |
Estimate only. Assumes solar charges the battery daily (savings = rate minus feed-in on shifted energy), battery sized to cover overnight use +10%, rebate per the federal Cheaper Home Batteries Program (tapered above 14 kWh usable, current at July 2026). Real payback depends on usage patterns and tariffs — we model it properly in your quote. South West Tech — 0488 224 284.