LET’S PUT SOME NUMBERS TO IT
What could your
home save?
Enter your electricity bill or daily use. We’ll recommend a battery with enough usable capacity to cover your whole day.
No contact details needed to calculate.Compare with savings & stocksYOUR ESTIMATED ANNUAL SAVING
That’s about — a month.
An estimate, not a guarantee. Final costs and suitability are confirmed after a survey.
Find the right fit.
See the usable storage, daily-use coverage and standard price for each combination.
Explore every battery and inverter combination
Standard prices include your selected EV and solar-connection options. Availability follows the September 2026 price list.
| Range | Battery | Inverter | Usable daily | Coverage | Standard price | Annual saving | Net saving | Choose |
|---|
BATTERY. SAVINGS. STOCKS.
What could the same
money do for you?
Compare the bill savings from your battery with interest from a savings account and an illustrative stock-market return.
4.5% and 7% are example assumptions from our model. Enter your own rates; these are not current offers or forecasts.
This compares paying the full system price upfront with investing the same amount. Loan interest and mortgage repayments are excluded.
The first-year picture.
First-year saving or return, before tax and feesThe battery percentage is annual bill savings divided by its price. The purchase cost still needs to be recovered. Savings and stocks retain an underlying balance, so the annual figures alone don’t tell the whole story.
AFTER YOUR BATTERY PURCHASE
Where you stand,
year by year.
See your total electricity savings each year, after subtracting the cost of your selected battery.
Years from installation · financial position (£)
Each bar = total electricity bill savings to that year − the upfront system price. Zero is the point where those savings have paid back the cost. No interest is added to the savings.
See the year-by-year figures
| Year | That year’s saving | Total savings | Your position |
|---|
What the figures assume
The bars use your selected system’s standard price and estimated electricity savings. They assume the system is paid for upfront and show bill savings, not a bank balance or the battery’s resale value.
Rates and yearly usage stay constant. Charging losses, tax, inflation, degradation, servicing, replacements and finance costs are excluded. The model assumes the battery operates at the same performance for the full selected period.
The savings-account and stock figures above illustrate the first year only. Stock returns can be negative and savings rates can change. All figures are estimates.
Further reading: MoneyHelper: saving and investing · FCA: investment risks
How we calculate and recommend
Your electricity use: we subtract the fixed standing charge from your monthly bill and divide the rest by your current blended rate. Or enter daily kWh directly. Monthly bills give an average day; use a higher-demand day if you want a more cautious size estimate.
Usable capacity: 90% of the labelled battery size is available each day. A 10 kWh battery supplies 9 kWh; 15 kWh supplies 13.5 kWh; 20 kWh supplies 18 kWh. The largest listed 40 kWh battery supplies 36 kWh.
Your recommendation: choose the lowest-priced listed battery/inverter combination whose usable capacity covers 100% of the daily usage entered. We never recommend a smaller battery just because it has a quicker payback. If daily use exceeds 36 kWh, a tailored quote is needed.
Before a battery: all consumption is priced at the entered blended rate (32p/kWh by default), plus the standing charge. With a correctly sized battery: all consumption is priced at the entered overnight rate (7p/kWh by default), plus the same standing charge. If you manually choose a smaller battery, its uncovered usage stays at the blended rate.
Annual saving: daily use covered by the battery × (blended rate − overnight rate) × 365, converting pence to pounds. Standing charges are unchanged and do not create a saving. All calculations use 57.19p/day: Ofgem’s July–September 2026 GB Direct Debit average, including VAT, held constant for the illustration. This is a GB benchmark, not a Northern Ireland tariff.
This simplified scenario assumes the battery fully recharges every night and can supply the demand entered. The 90% factor represents usable capacity, not round-trip efficiency. Charging losses, peak loads, seasonal changes and recharge-speed limits are not modelled. Inverter sizing and overnight charging must be confirmed at assessment, so full coverage here is not a guarantee about every day’s actual bill.
Standard September 2026 prices are used. EV and solar connection add to the price but no separate savings are modelled. Solar generation, export income, degradation, maintenance, replacement, inflation, tax changes and borrowing costs are excluded.
YOUR NEXT STEP
A quote built
around your home.
Tell us what you need. We’ll help you find the right battery and arrange your personalised quote.
Get your free quote
Tell us where you’d like the battery installed and how to contact you.