Should you get solar panels with a battery?

Is it worth getting a battery with solar panels?

On solar savings alone, only if the battery adds little to the price. The test is the difference between two quotes from the same installer, one with the battery and one without, against what the battery adds each year. To show the sums we adapted a worked example from MCS's standard: a home empty for half the day, using 3,500 kWh a year, with a 3 kWp system making 2,775 kWh, which uses 805 kWh of that solar at home without a battery and 2,276 kWh with 9 kWh of battery for solar [3]. MCS's own example has a battery with 13 kWh usable with 9 kWh of it for solar; we treat it as a battery of 9 kWh usable, a hypothetical variation, and MCS gives such figures as averages for similar homes, not a real household.

Our calculation from the government's median rate for batteries of 6 to under 11 kWh gives £8,900 for a battery of about 10 kWh nominal, the size that holds 9 kWh usable [2]: well above what this example could repay. Cheap overnight charging, more use in the evening or a lower quote can change that; the full sums are on is a solar battery worth it. For the whole system, the table below adds the government's separate solar and battery figures; these are constructed scenario costs, not package prices.

How much do solar panels with a battery cost?

There is no official price for solar and battery packages: the government publishes solar and battery installation costs separately. Adding its 2025-26 medians gives about £4,800 for 3 kWp of panels plus £8,900 for a battery of about 10 kWh nominal, £13,700 together, by our calculation; these are constructed scenarios, and adding two medians does not give the median price of a package [1][2]. The solar median covers all installations up to 4 kW in Great Britain, including new builds and non-domestic ones; for existing homes the mean was higher, £2,109 per kW against £1,808 for all installations [1]. A package from one installer may cost less: MCS and the Energy Saving Trust both say fitting them together can save money [4][5], and DESNZ does not say whether a hybrid inverter's cost sits in its solar or its battery figures, so adding them could count it twice.

On those figures a 5kW solar system with a 5 kWh (nominal) battery comes to about £14,200, and a 10kW solar system with 10 kWh (nominal) of battery storage about £20,900 to £24,400, by our calculation. A written quote with both options itemised is the real figure; prices by size are on solar panel costs and solar battery costs.

Should you add the battery now or later?

Now can be cheaper per job: MCS says fitting a battery with the panels is often the most cost-effective option, and the Energy Saving Trust says you should be able to save money because the installer is already on site [4][5]. Neither gives a figure, and we found no official one. Three things change if you wait:

• VAT. A battery installed in a home is zero-rated until 31 March 2027 and due to be 5 per cent from 1 April 2027 [12]: on our illustrative £8,900 that is about £450 more, by our calculation.
• The inverter. A battery added later either has its own inverter or connects to a hybrid inverter that also runs the panels [13]. A hybrid inverter keeps the second route open only for batteries that inverter is compatible with, so ask which ones, and for the price of both routes.
• The network limit. A battery with its own inverter adds its output to the solar inverter's. Above 16 amps per phase in total, 3.68 kW on a single-phase supply, the network operator's G99 approval comes first, and a 3 kW solar system with a 3 kW battery on one single-phase supply is over that limit [13][14]. The details are on adding a battery to existing solar.

If you want a battery anyway, for a cheap overnight or battery tariff or for backup in a power cut, fitting it with the panels can cost less [5], and before 1 April 2027 it carries no VAT [12]. Some batteries need extra equipment for backup [15]. Otherwise, panels on their own keep the choice open: a battery can be added later with its own inverter, or on a hybrid inverter if you choose one now, with a battery it is compatible with [13].

Is it better to get more solar panels or a battery?

Compare what each adds to your quote with what it adds each year. The extra cost of one more kWp depends on the job: it may share scaffolding and wiring already planned, or need a larger inverter, so only your installer can price it. In MCS's example, each kWp makes about 925 kWh a year on that roof [3]. Even if all of it were exported, that is worth £28 a year at a 3p export rate and £111 at 12p, by our calculation; used at home it is worth more.

The export rate pulls the two apart: a good rate makes extra panels earn more and leaves a battery less to save, which the Energy Saving Trust also found for batteries [6]. Roof space, shading and the inverter set the real limit on more panels.

Do solar panels work without a battery?

Yes. Without a battery, the home uses solar as it is generated and the rest is exported: in MCS's example, 805 of 2,775 kWh used at home and the rest exported [3]. Payment for exported electricity comes from a Smart Export Guarantee supplier, at a rate each sets; in 2024-25, the average rates paid were 15.4p per kWh on tied tariffs and 7.3p on untied ones, Ofgem reports; these are past averages, not rates you can get today [8]. Whether panels alone are worth it for your home is on are solar panels worth it.