TOOL
Battery Calculator
This calculator models the two main ways a home battery is used in Edinburgh: storing surplus solar instead of exporting it, and charging from the grid at off-peak times then using that energy during peak hours. In Scotland, grid arbitrage is often the larger share because solar yield is lower and the peak/off-peak spread can be wide.
Your assumptions
Adjust any value. All defaults are editable.
Illustrative annual energy
Breakdown (annual)
| Solar stored → used at peak | 1285 kWh/yr |
| Grid arbitrage (off-peak → peak) | 3916 kWh/yr |
Year-by-year (with degradation)
| Year | Capacity factor | Energy delivered |
|---|---|---|
| 1 | 97.5% | 5,071 kWh |
| 2 | 96.0% | 4,995 kWh |
| 3 | 94.6% | 4,920 kWh |
| 4 | 93.2% | 4,846 kWh |
| 5 | 91.8% | 4,774 kWh |
| 6 | 90.4% | 4,702 kWh |
| 7 | 89.0% | 4,632 kWh |
| 8 | 87.7% | 4,562 kWh |
| 9 | 86.4% | 4,494 kWh |
| 10 | 85.1% | 4,426 kWh |
How this calculator works
Energy delivered: battery capacity × cycles per day × 365.
Solar stored [A]: the smaller of your daily solar surplus and the charge needed (charge kWh = delivered ÷ RTE), × RTE.
Grid arbitrage [B]: the remaining charge drawn from the grid off-peak, × RTE.
Degradation: 2.5% in year 1, then 1.5% per year thereafter (0.93 average over 10 years).
Maximum 2 cycles per day. This is the house rule on every quotation — the website does not contradict it.
All figures are illustrative and should not be relied upon for financial decisions. Savings confirmed on your written quote.
Get a battery quote → or call 0141 230 0198
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Click the box above to copy. Published August 2026. Updated quarterly.
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