Battery or no battery?

By Owen Price, surveyor · 15 September 2026 · 6 min read

Almost every quote we write now has the same question at the bottom: is a battery worth it? For some homes it pays for itself; for others it never will. Here is how to tell which yours is.

What a battery actually does

Solar panels make most of their power in the middle of the day, when many homes use the least. Without a battery, the spare power goes to the grid and you are paid a small amount for it. In the evening, when the kettle and the oven go on, you buy power back at the full price.

A battery stores that midday power and gives it back in the evening. You use more of your own electricity and buy less. That is the whole idea: a battery does not make your panels produce any more.

So the question is simple to ask and harder to answer: how much would you save by moving power from noon to six o'clock, and how long would that take to pay back the battery?

Side by side

Sample figures for a three-bedroom house with a 4 kW system, using about 3,400 units a year:

Item	Panels only	Panels and battery
Typical cost, fitted	$6,500	$10,000
Solar power you use yourself	About 35%	About 70%
Saving in a year	About $520	About $850
Pays for itself in	11 to 13 years	11 to 14 years
In a power cut	Off, for safety	Some sockets stay on, with backup wiring
Best for	Homes with someone in during the day	Homes empty by day and busy in the evening

Sample figures for 2026, before any grant. Your survey gives your own numbers.

Who a battery suits

Our rule of thumbIf you use most of your electricity after 5pm, a battery is worth a quote. If someone is home all day, start with panels only and add a battery later.

Batteries suit households that are out during the day and busy in the evening. They also suit homes with an electric car, or on a tariff with cheap night rates, because the battery can top up overnight at the lower price too.

If someone is home most days, or you run the washing machine and dishwasher at lunchtime, you already use much of your solar power as it is made, and a battery adds less.

If you are not sure, there is no rush. Every system we fit is ready for a battery, and adding one later costs about the same as adding it now.

Four questions to ask any installer

How much of the battery can you actually use, not just its headline size?
How many years, or how many full charges, does the warranty cover?
Can it keep some sockets on in a power cut, and what extra wiring does that need?
Will it work with the panels and inverter you already have?

A good installer answers all four in writing, before you sign anything.

See both prices for your roof

We survey for free and quote with and without a battery, side by side, so you can decide with your own numbers.

Book a free survey

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