Around eight in ten solar panel owners we spoke to either own, or would consider buying, a battery to store excess electricity they generate. Exclusive Which? research reveals what solar battery owners really think of them and their top tips before you buy.

Which -Solar Panel Batteries


While just 6% of the solar panel owners in our survey already have a solar battery, another 74% said they would consider one. A year ago, we found that 60% either owned a battery or would consider one – so interest is growing fast in this relatively new tech.

The opportunities to get paid for giving excess electricity to the grid are very limited at the moment. It’s no surprise, then, that those who bought solar panels recently are more likely to have a battery installed. A third of battery owners bought theirs in the past year, whereas just 18% have had theirs for more than three years.

So if you’re planning to install solar panels, should you also install a battery to maximise the power you generate? We surveyed 1,987 Which? Connect members who have solar panels in May 2019, including 119 who own a solar battery, to find out. If you’re considering installing solar PV, check the best solar panel brands according to those who own them.



What is a solar panel battery?

Install a battery and you can store any excess renewable electricity that your solar PV generates, rather than exporting it to the grid. This means you can make the most of your free electricity and use it at a time that suits you. Batteries range in size from around 1kWh to 8kWh. A 4kWh system would store enough electricity to boil a kettle around 37 times.

Solar panel battery storage: what owners think

The most popular brands, according to our survey, are Tesla, Solax, Powervault and LG. But we haven’t tested solar batteries, nor do we have enough owners in our survey to rate the brands. However, the vast majority of owners said that the battery installed in their home has met their expectations for saving money on electricity and cutting their carbon footprint.

To what extent did your solar battery meet your expectations?

battery storage survey


Owners were much less positive about their solar batteries meeting their expectations when it comes to providing back-up in a power cut, however – keep reading to find out more. You’ll notice that lots of owners answered ‘don’t know’ to some of the questions. This is likely to be because they haven’t owned their battery for long enough to know.

Read more: – Which?