Last updated: May 2026
Why examples help
A home battery can look very different depending on the assumptions used. A small battery with low peak usage may have a weak payback, while a regularly cycled battery on a strong off-peak tariff may look more attractive.
These examples use the same calculation logic as the calculator, so they are useful starting points rather than separate hand-written figures.
Example scenarios
Scenario
Small battery / low usage
A cautious example with a smaller battery, lower peak-period use and fewer yearly cycles.
Annual saving
£159
Monthly saving
£13
Payback period
28.3 years
Saving per cycle
£0.64
Input assumptions
- Battery capacity: 5 kWh
- Useful peak usage: 4 kWh
- Installed cost: £4,500
- Warranty: 10 years
Tariff assumptions
- Peak rate: 27p/kWh
- Off-peak rate: 10p/kWh
- Efficiency: 90%
- Cycles per year: 250
This looks hard to justify on savings alone because the payback period is much longer than the warranty period.
Scenario
Typical off-peak charging
A middle-ground example using a 10 kWh battery, cheap overnight charging and regular cycling.
Annual saving
£485
Monthly saving
£40
Payback period
10.3 years
Saving per cycle
£1.62
Input assumptions
- Battery capacity: 10 kWh
- Useful peak usage: 8 kWh
- Installed cost: £5,000
- Warranty: 10 years
Tariff assumptions
- Peak rate: 28p/kWh
- Off-peak rate: 7p/kWh
- Efficiency: 90%
- Cycles per year: 300
This looks marginal because the estimated payback period is longer than the warranty period.
Scenario
High peak usage
A stronger-use example with a larger battery, higher peak usage and more yearly cycles.
Annual saving
£858
Monthly saving
£71
Payback period
7.6 years
Saving per cycle
£2.60
Input assumptions
- Battery capacity: 13.5 kWh
- Useful peak usage: 12 kWh
- Installed cost: £6,500
- Warranty: 10 years
Tariff assumptions
- Peak rate: 30p/kWh
- Off-peak rate: 7.5p/kWh
- Efficiency: 90%
- Cycles per year: 330
This looks potentially worthwhile because the estimated payback period sits within the warranty period.
What these examples show
The same battery can produce very different results depending on how much useful peak-rate electricity it replaces and how strong the gap is between peak and off-peak prices.
Installed cost also matters heavily. A cheaper battery with slightly lower capacity can sometimes have a better payback than a larger, more expensive system.
Best next step
Use the home battery savings calculator to test your own quote, tariff rates and expected peak-period usage.
Estimate your own numbers
The examples above are only general scenarios. Your result depends on your battery size, tariff rates, installed cost, efficiency and how often you use the battery.
Use the home battery savings calculatorRelated guides
Keep learning
These related guides explain the assumptions behind home battery savings, payback period and quote checks.
Is a home battery worth it in the UK?
Understand when a battery may make sense, when it may not, and which numbers matter most.
Read guide →
Is a home battery worth it without solar?
Learn how grid charging on cheap off-peak electricity can work even without solar panels.
Read guide →
How to estimate battery payback period
See how installed cost and annual saving combine to produce a simple payback estimate.
Read guide →