Are Solar Batteries Worth It in the UK?

A solar battery is worth it if you have spare solar power by day and use a lot in the evening. It stores the extra for later, so you buy less from the grid. It pays off less where most power is used at midday.

What a battery actually does

Panels make power while the sun shines. You often use more power in the morning and evening. A battery bridges that gap by storing the midday surplus.

Without a battery, surplus power goes to the grid. However, you may earn a payment for it, as our guide to the Smart Export Guarantee explains. With a battery, you keep more of that power for your own use.

That matters because of the price gap. Ofgem’s price cap for October to December 2026 averages 26.32p per kWh for electricity. Export rates vary by supplier and are set separately. Power you store and use replaces power you would have bought at the higher price.

When a battery makes sense

A battery tends to suit homes with these habits, so check how many apply to you.

• Someone is out all day, so little solar power gets used at home.
• Evening use is high, from cooking, heating, laundry and charging.
• The solar array is large compared with daytime demand.

It suits fewer homes when someone is in all day and already uses the solar power directly. In that case, the battery has less surplus to store, so the payback is slower.

Sizing: kWh and kW

MCS tells consumers to choose a battery on two numbers. Capacity in kWh is how much energy it stores, while power in kW is how much it can deliver at once.

Start with your own use, since every home differs. Ofgem’s typical medium home uses 2,500 kWh a year from 1 July 2026. That is about 6.8 kWh a day on average, which we worked out from the yearly figure. Your own bills will give a better number.

A battery far bigger than your evening use rarely fills, yet one that is too small runs out early. Ask your installer to model your half-hourly use, then compare two or three sizes.

Solar output matters first

A battery only stores what the panels make, so the size of the array comes first. Our guide on how many solar panels you need covers that step.

Local sunshine also changes the picture. PVGIS modelling gives a south-facing kilowatt of panels 979 kWh a year in Nottingham and 981 in Leicester. Sheffield gets 947.

See solar panels in Nottingham, solar installers serving Leicester and how solar performs in Sheffield for the full local pictures. In each, the summer surplus is what fills a battery, though winter surplus is small.

Questions to ask yourself first

Before you ask for quotes, answer these honestly.

• When is the house empty, and when is it busy?
• How much of my solar power do I use directly today, or expect to?
• Would a bigger array help more than a battery?
• Can I afford the upfront cost, and when is it due?

Sometimes extra panels bring more benefit than storage, yet this depends on your roof. Ask any installer to model both options.

Buying a battery with new panels or later

You can fit a battery with a new system or add one to panels you already own. HMRC says standalone batteries and retrofits qualify for the zero rate from 1 May 2023 to 31 March 2027.

The rate reverts to 5% from 1 April 2027, so timing can affect your cost. Our post on VAT on solar panels covers the detail.

If you add a battery later, the grid rules may change. The 16 A limit counts all generators. For example, a 3 kW solar system plus a 3 kW battery on one single-phase supply falls under G99. Our G98 and G99 guide explains the process, and your installer handles the paperwork.

The MCS battery standard is MIS 3012. It covers installers who supply, design and fit battery systems up to 50 kW, so choose an installer who works to it. Our guide to MCS-certified solar installers shows how to check.

Help with cost

Support depends on where you live and your income, and it can change. In England, Warm Homes: Local Grant includes solar PV and batteries for eligible low-income households. Eligibility is for private homes with an EPC rating of D to G.

In Scotland, Home Energy Scotland lists only hybrid solar PV-T for funding, not standard solar or batteries. In Wales, Nest can recommend a package that might include solar panels. Check each scheme directly, because rules change.

How to judge a quote

Ask for these in writing, because they let you compare quotes fairly.

1. The battery capacity in kWh and its power in kW.
2. The expected share of your solar power you will use with and without the battery.
3. The warranty and what it covers.
4. Whether the quote includes any grid-connection work.
5. The VAT treatment, given the date of installation.

Be cautious with any promise of exact savings. Savings depend on your habits and tariff, so we cannot give a figure that suits every home.

Next steps

If a battery interests you, read about solar battery storage to see what an installer will cover. Compare at least two quotes, because designs and prices vary.

When you are ready, you can ask for quotes from MCS-certified installers. Your enquiry goes into a central dashboard, because nobody is contacted automatically.