A home battery for solar panels: the sums before you buy
A battery produces no energy: it stores what you have spare at midday so you can use it at night. Its value depends on a single subtraction, and it is worth doing before asking for a quote.
The subtraction that decides everything
Without a battery, a spare kWh is credited at about 0.06 €. With a battery, that same kWh is used at night instead of buying it at about 0.22 €. Each kWh that goes through the battery is therefore worth about 0.16 €, before charging and discharging losses.
An example with a 4.8 kWh battery that fills and empties completely 300 days a year: 1,440 kWh, about 230 € a year at most. In winter, or if you are not home at night, it is used less, and the saving drops.
What the modules cost
| Module | Capacity | Price with VAT | Note |
|---|---|---|---|
| Pylontech US5000 | 4.8 kWh | 898.71 € | module only; over 6,000 cycles, 10 year warranty |
| Huawei LUNA2000 | 5 kWh | 2,208.55 € | module only, without the control unit; 10 year warranty |
These are shop prices for the module, not for an installed battery: add the hybrid inverter if yours is not one, the control unit, cabling and labour. We have not found an installed battery price published by a reliable source, so we do not write one: ask for a fixed price in the quote and divide it by the 230 € a year in the example, or by your own figure.
When it makes sense
- When you live in the house all year and use a lot at night.
- When your panels already export a lot of surplus at midday.
- When you want some power during an outage, and your equipment has a backup function (not all do: ask).
In a holiday home used a few months a year, the battery spends most of the year with nobody to use what it stores.
We do not install batteries or do electrical work, and we have no partner installers.
Where the figures come from
Prices checked in September 2026. They change: take them as an order of magnitude and always ask for the final price in writing.
Questions about this
How many years does it last?
Can I add one to existing panels?
Tell us about your home, we will reply
If you have a question about your numbers, write to us. We do not install batteries: we reply with what we know.
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