Battery Storage Self-Consumption Calculator
Estimate how much solar energy you can save, reduce grid reliance, and calculate your annual financial savings by adding a home battery storage system.
Quick Estimate or Detailed Projection?
Whether you’re exploring the basic benefits of battery storage or modelling specific system parameters, pick the tool below to get instant, accurate results.
Quick Battery Savings Estimate
Get a fast projection using standard UK household assumptions
Savings Projection
Estimated self-consumption increase and financial savings
Enter your system details, then click Estimate Savings.
Detailed Battery Projection
Fine-tune with specific cycle counts, efficiency, and baseline rates
Typical lithium-ion: 85-95%
UK average is ~250 (5x per week)
Without battery (typically 30-40%)
Detailed Projection
Comprehensive breakdown of energy flows and savings
Enter your detailed parameters, then click Project Detailed Savings.
Battery Storage Quick Reference
Typical values for UK solar and battery systems. Use these as a guide if you are unsure of your exact figures.
| Metric | Typical Value | Notes |
|---|---|---|
| Average UK Solar Generation | 3,500 – 4,500 kWh/yr | Based on a 4kWp system in Southern/Central UK. |
| Average UK Household Usage | 2,700 – 3,500 kWh/yr | Ofgem typical medium usage household. |
| Baseline Self-Consumption | 30% – 40% | Without a battery, most solar is exported or used instantly. |
| Self-Consumption with Battery | 60% – 80% | Properly sized batteries can double self-consumption rates. |
| Battery Round-Trip Efficiency | 85% – 95% | Energy lost as heat during charging/discharging. |
| Typical Annual Cycles | 250 – 300 | Equates to roughly 5 to 6 full cycles per week. |
Battery Storage FAQ
Everything you need to know about calculating self-consumption and evaluating home battery storage.
Solar self-consumption is the percentage of electricity generated by your solar panels that is used directly in your home, rather than being exported to the national grid. A higher self-consumption rate means greater savings on your electricity bills.
A home battery stores excess solar energy generated during the day that would otherwise be exported to the grid at a low rate. You can then use this stored energy in the evening or at night, increasing your self-consumption rate from a typical 30-40% up to 60-80%.
In the UK, a typical home battery system averages around 250 to 300 full cycles per year. This equates to roughly 5 to 6 cycles per week, depending on your household’s energy consumption patterns and solar generation.
Without a battery, a typical UK household achieves a self-consumption rate of 30% to 40%. With a properly sized battery storage system, this can realistically be increased to 60% to 80%, significantly reducing reliance on grid electricity.
Yes, for most households with solar panels, battery storage is financially worthwhile. With UK electricity prices remaining high and smart export guarantees (SEG) relatively low, storing your own free solar energy for evening use provides a much better return on investment than exporting it.
Yes, but with diminishing returns. A 5kWh battery will capture most of the daily excess solar for an average household. Jumping to 10kWh or 15kWh may only marginally increase self-consumption if your daily solar generation doesn’t consistently exceed the smaller battery’s capacity.