Solar battery storage in Wales

A solar battery stores spare electricity from your panels for use later. Without one, a home uses what its panels make during the day and exports the rest. With one, you can use more of your own power in the evening.

This page explains what battery storage involves in Wales, what shapes the price and what to look for in a quote. Solar Cymru is an independent guide and enquiry service, and we do not fit batteries ourselves.

What battery storage involves

An installer fits the battery and connects it to your inverter, so it charges from your panels. Some batteries can also store power from the grid. MCS runs a separate standard for batteries, MIS 3012, which covers batteries up to 50 kW in permanent buildings. Ask whether your installer holds certification to it.

You can fit a battery with new panels or add one later. Either way, the installer should size it to your use. Ofgem sets typical household electricity use from July 2026 at 1,600, 2,500 and 3,800 kWh a year on a standard meter. Check your own bills against those figures, since a battery pays off only if you use the stored power.

What affects the price

The Energy Saving Trust says a home battery typically costs around £5,000 to £8,000. Which? says prices can run from under £2,000 to £10,000, depending on capacity, type and brand. A battery bought with panels usually costs less than one added later.

VAT helps here. Electrical storage batteries have carried the reduced VAT rate since 1 February 2024. That covers a battery added to an existing system and one fitted alone. The rate is 0% until 31 March 2027, and then 5% applies unless the law changes. A battery fitted at the same time as panels gets the same rate as the panels.

Value is harder to pin down than cost. Using solar power at home is worth more than exporting it. For example, the Ofgem price cap electricity rate is about 26p per kWh from October to December 2026. In contrast, Ofgem found an average export rate near 4.4p on untied Smart Export Guarantee tariffs in 2024-25. That comparison uses two figures from different periods, so treat it as a guide only.

Our post asking whether a solar battery is worth it in Wales works through these numbers. Meanwhile, our post on how much solar panels cost shows the price of the panels that feed a battery.

Planning, grid and funding points

Planning rules in Wales focus on the panels a battery pairs with, so read our planning permission guide for Wales. Building Regulations still apply to the electrical work, and the installer should arrange the certificate.

Grid rules matter more. A battery counts towards your system rating, so a panel and battery combination can tip you from the simple G98 route into G99. Systems above 16 amps per phase need the operator’s agreement before commissioning. Our post on G98 and G99 for Welsh homes explains the two routes. Our grid and export guide covers the network operators.

Export payments change with a battery. The Smart Export Guarantee requires suppliers to pay for exported power, yet rates vary widely. Ofgem found that tied tariffs, which bundle a product such as a battery, averaged about 14.5p in 2024-25. Read the terms before you sign, and see our post on the Smart Export Guarantee in Wales.

On funding, there is no dedicated UK Government grant for solar or batteries. However, Green Homes Wales offers owner-occupiers interest-free loans of £1,000 to £25,000 that can fund solar with a battery. The scheme does not support listed homes and depends on funding availability. Our solar funding guide for Wales lists the other routes.

Batteries, cars and heat pumps

A battery suits homes that add other electric loads. For instance, you can charge an electric car while panels generate, which cuts running costs. Our post on charging an electric car with solar looks at the options.

Similarly, solar can power a heat pump, though an air source heat pump costs around £12,000 before grants. Read about solar panels and heat pumps in Wales before you plan both.

What a good quote contains

A good battery quote names the model and states its usable capacity. It shows how the battery connects to your inverter and what it charges from. It also says whether the installer holds MCS certification for batteries. MCS requires a quote to make that clear when the installer is not certified to MIS 3012.

Ask who handles the network paperwork and what the warranty covers. Ask what happens if the battery fails, and whether the price includes VAT at the right rate. Compare two or more written quotes side by side.

Ask for the panels and the battery priced together, and then priced separately. That way you can see what the battery adds. Under HMRC rules, a battery fitted at the same time as panels counts as part of one supply, so the VAT rate matches. Our guide to choosing an installer lists further checks on contracts, deposits and protection.

How the Solar Cymru enquiry works

You complete a short form on our get quotes page and say you want a battery. Solar Cymru passes your enquiry to MCS-certified installers through the MoreLeadz lead system. An installer then replies about a survey and a written quote.

The step is opt-in, so you decide whether to go ahead. We are not an installer, lender, broker or government service. For panel and roof questions, see our page on solar panel installation in Wales.