They claim to save you hundreds of pounds on your electricity bill, help you towards electricity self-sufficiency, and even let you play a part in the National Grid. Are you tempted by a home battery?
Energy storage systems – also known as batteries – store electricity in your home so you can use it when you need it. Usually this is electricity generated by a renewable system, such as solar PV or a wind turbine, but you can also store electricity from the grid.
And it looks as though batteries are moving into the mainstream.
Eon launched its solar and storage offering last month and it claims that installing a battery can help you use 30% more of the electricity you generate than with solar panels alone. Combined, it says you could make £560 a year in savings and earnings.
This week, Nissan also announced it’ll be selling home batteries – customers can choose a battery previously used in an electric car, or the pricier option of buying brand new.
And Tesla, which is more famous for its cars, sells a home battery it claims can power the average two-bedroom house for a day.
It’s early days yet for home battery storage but, with over 900,000 solar PV installations in the UK, its potential to grow is huge.
Battery storage benefits
If you have solar PV, wind or hydro turbine, it may generate most electricity when you’re not at home to use it. Unused electricity is exported to the grid and you’ll probably import electricity in the evenings.
Batteries store excess renewable electricity so you can use more of what you generate and help cut your electricity bills. They range from around 1kWh to 8kWh, which the Energy Saving Trust says is enough energy to boil your kettle between 10 and 70 times.
There’s also the potential, with time-of-use tariffs, to charge your battery from the grid when electricity is cheaper, and use up your store at times of day when electricity is more expensive.
So how much money you could save depends on the system you have installed and how it’s used. Many technologies are too new for there to be independent data to estimate typical savings yet.
Battery storage isn’t regulated either, although the Renewable Energy Consumer Code (RECC) was recently extended to include battery storage systems. Installers signed up to the code agree to abide by high consumer protection standards. RECC said that it has seen ‘increased interest in these products’, but also ‘a rise in complaints citing mis-selling’.
We’ve heard from Which? members with battery systems who have very different views on them. One told us about reducing their energy bill to less than £20 per month, while others have complained about systems not working as expected and installation problems. Some found the cost off-putting.
So, do you have a home battery installed? How do you use it and what do you think of it? Is there anything you wish you’d known in advance?