Cost guide
How much does battery storage cost?
A 5 kilowatt hour battery installed is £3,500 to £5,500 and a 10 kilowatt hour system £5,500 to £8,000. Fitting it at the same time as a solar array saves roughly £500 to £900 in shared labour and one set of paperwork.
Typical prices
Ranges, not quotes. A quote depends on your room.
| Work | Typical UK price |
|---|---|
| 5 kWh battery, AC coupled retrofit | £3,500 to £5,500 |
| 10 kWh battery, AC coupled retrofit | £5,500 to £8,000 |
| Battery fitted alongside a new solar array | £3,000 to £7,000 |
| Power cut backup, essential circuits board | £700 to £1,600 |
| Additional module on a stackable system | £1,200 to £2,400 |
| Inverter replacement at end of life | £900 to £2,000 |
Compare quotes on usable kilowatt hours and on the warranted throughput, not on the headline capacity and the number of years. Two batteries with the same figure on the box can differ by a third once both are read properly.
What moves the price
- Usable capacity, which is what the price should be compared on.
- AC coupled retrofit against DC coupled with a new array.
- Where the battery goes. A garage or utility wall is straightforward; a loft raises weight and temperature questions.
- Distance from the battery to the consumer unit and the incoming tails.
- Whether power cut backup and a separate essential circuits board are included.
- Whether the distribution network operator application is G98 or G99, which depends on total inverter capacity.
Who quotes for it
3 of the 133 electricians listed on this site take on battery storage.
Most of them in one place: Birmingham (1), Glasgow (1), Rotherham (1).
Questions about battery storage
How long will it last?
Lithium iron phosphate cells are generally warranted for ten years or a stated throughput, whichever comes first, and degrade gradually rather than failing. Ask what the warranty promises the capacity will still be at the end of it.
Will it keep the house running in a power cut?
Only if it was specified to. A standard install disconnects when the grid fails. Backup needs extra hardware and a decision about which circuits are worth keeping, and it is much cheaper to include than to add later.