When we surveyed Which? members in 2019 about their solar panels, 106 of our 1,987 survey respondents had battery storage. 25% paid less than £3,000 for their battery system, while 41% paid between £4,000 and £7,000 (excluding the cost of the PVs themselves).

Installing a home- solar battery storage uk system is a long-term investment to make the most of your solar-generated energy and help cut your energy bills.

Whether a battery will save you money depends on

the cost of installation

the type of system installed (DC or AC, chemistry of the battery, connections)

how it’s used (including the effectiveness of the control algorithm)

the price of electricity (and how it changes during the lifetime of your system)

the battery’s lifetime.

Several battery systems come with a 10-year warranty. They require little maintenance, so the main cost is the initial installation. However, solar PV panels can last 25 years or more, so you should factor in the cost of replacing the battery at least once into your total costs.

Batteries are expensive to buy, but prices are dropping all the time, as are solar panel prices. With electricity prices at record highs, the payback times are improving.

Some battery storage companies offer financial benefits – for example, payments or reduced tariffs for providing services to the grid (eg. letting spare electricity from the grid be stored in your battery). If you have an electric vehicle, being able to store cheap electricity to charge it could help to cut your costs.

We haven’t yet tested home-energy storage systems to be able to calculate how much they could cost or save you. However you should take into account whether you are on a tariff which has different electricity costs depending on the time of day (time-of-use, or TOU tariff) and, if you generate your own electricity, how much of this you use already.

If you get the Feed-in Tariff (FIT), part of it is based on the amount of electricity you generate and export to the gird. You’ll need to have signed-up already to receive the FIT as it is closed to new applications. If you don’t have a smart meter the amount of electricity you export is estimated at 50% of what you generate.

If you have a smart meter, your export payments will be based on actual export data. However, if you also have a home battery installed, your export payments will be estimated at 50% of what you generate. This is because your export meter cannot determine whether electricity exported from your battery was originally generated by your panels or taken from the grid.

If you are looking to install solar panels and a solar battery, new Smart Export Guarantee (SEG) tariffs mean that energy firms will pay you for any excess renewable electricity you have generated and export to the grid. All suppliers with more than 150,000 customers have to offer them, but the rates are not very generous.

Compare rates to find the best for you – but check that you’re eligible if you have storage installed.