UK Battery Storage Savings Calculator
Estimate the annual bill saving a home battery delivers. Compare battery sizes, tariffs and charging strategies to see how much less you would pay each year.
Independent UK energy information from PowerGuardian.
See all your savings in one place
Enter your home details once and get personalised savings, supplier picks, recommended actions, calculators and guides on My PowerGuardian.
Figures reviewed June 2026 and updated monthly where appropriate. All results are estimates.
Most UK homes fit 5–10 kWh of usable storage.
Charge overnight at a cheap rate, use it during the day.
The rate you'd otherwise pay for grid electricity.
The cheap rate you charge the battery at (e.g. overnight).
Leave blank to use a typical UK figure of about £700/kWh installed.
This tool assumes about 90% round-trip efficiency and roughly 330 useful cycles a year. It uses simple payback and doesn't model finance costs, battery degradation or future price changes. Results are an estimate, not a guaranteed return.
Estimated annual saving
£252
Simple payback period
13.9 yrs
10-year net return
-£976
Monitor and get more from your storage
Independently chosen kit that helps UK households cut energy use.
Tapo P110 Smart Plug (Energy Monitoring)
See exactly which appliances are quietly inflating your bill — track real-time watts, kWh and runtime from your phone.
- Real-time energy monitoring
- Cuts standby/vampire power
- Schedule appliances off-peak
Estimated benefit: ~£40/yr standby savings
Shop on Amazon
Home Energy Monitor (Whole-House)
Track your whole-home electricity use live and find where the kWh are going before the bill lands.
- Whole-house live usage
- Spot expensive habits fast
- App history & alerts
Estimated benefit: Awareness cuts ~5-10% use
Shop on AmazonAffiliate links — we may earn a small commission at no extra cost to you. This keeps PowerGuardian free and independent.
Your next step
A battery can pay back within its warranty on the right tariff. Compare suppliers and off-peak deals, and keep an eye on the forecast to get the most from stored energy.
Monday UK Energy Savings Briefing
Receive one clear weekly email covering UK energy prices, supplier updates, tariff changes and practical ways to reduce household energy costs.
No spam. Unsubscribe anytime.
Tapo P110 Smart Plug (Energy Monitoring)
See exactly which appliances are quietly inflating your bill — track real-time watts, kWh and runtime from your phone.
- Real-time energy monitoring
- Cuts standby/vampire power
- Schedule appliances off-peak
Affiliate link — we may earn a small commission at no extra cost to you, which keeps PowerGuardian free and independent.
How the Battery Storage Savings Calculator Works
The calculator estimates how many kWh your battery usefully cycles in a year — your usable capacity, adjusted for round-trip efficiency, multiplied by roughly 330 cycles. It then values each stored unit by the price gap the battery lets you avoid, whether that's the difference between your peak and off-peak rates or between your unit rate and export rate for stored solar. The yearly saving is divided into the installed cost to give a simple payback period.
What Affects Battery Payback the Most
The single biggest factor is the price gap you can exploit. A wide gap between a cheap overnight rate and your daytime rate — or plenty of surplus solar you'd otherwise export cheaply — drives fast payback. On a flat single-rate tariff with no solar, there's little for a battery to save. Installed cost and how fully you cycle the battery each day also matter.
What Size Battery Should I Get?
Bigger isn't always better. A battery only earns its keep on the energy it actually cycles, so there's no point buying capacity you can't fill from cheap or solar power most days. Many UK homes land on 5–10 kWh of usable storage. Use the calculator to compare sizes against your own tariff before deciding.
Related PowerGuardian Tools
How home batteries work, what they cost and whether adding storage pays off.
Estimate the annual savings from solar panels before adding a battery.
Compare a standard tariff against an Economy 7 day/night tariff.
Estimate the cost of charging an electric vehicle at home.
Estimate your full annual bill from kWh usage, unit rate and standing charge.
Where energy prices are heading over the months ahead.
Thinking About Home Battery Storage?
Read our full guide to how batteries work, what they cost and how to tell if storage is worth it for your home.
Read the Battery Storage Guide