Are solar batteries worth it in the UK?

✔ Solar batteries cost about £4,500, on average

✔ A solar battery will typically last you 10–15 years

✔ Without a battery, you could lose around 50% of the power your panels produce

Solar energy is increasing in popularity, with more than 1.3 million UK households now taking advantage of falling solar panel costs to help cut their bills and emissions, and reduce their reliance on the grid.

If you’re one of the many turning to solar panels, you’ll want to know the benefits of solar batteries, too – they let you store more of the solar energy you generate, rather than letting the excess electricity go to the grid.

But are solar batteries actually worth it in the UK? We’ll answer that below.

If you’re already set on getting a solar PV system with a solar battery, why not fill in our web form to receive free quotes from trusted installers?

Is a solar battery worth it in the UK?

Financially, solar batteries are not currently worth getting if you want to either break even quickly or make a profit.

A battery for a three-bedroom property tends to cost around £4,500, which on top of the costs of a solar panel system, can be a barrier for many.

However, solar batteries are worth it if you want to reduce your reliance on grid electricity, because they allow you to store the electricity generated by your solar panels.

How much money does a solar battery save you each year?

A typical three-bedroom home will save around £669 each year with a solar battery and solar panel system. This is made up of the savings you’ll make from not buying electricity from the grid, and the money you can make exporting electricity the grid via the Smart Export Guarantee (SEG).

You’ll only receive a maximum of 15p per kilowatt hour (kWh), which is the rate currently paid out by Octopus Energy.

At 28.62p per kWh, electricity is more expensive than what you’d get via the SEG initiative, so you’ll save money if you simply store your excess energy in your solar battery for later.

The average three-bedroom house with solar panels will generate 2,645 kWh of electricity per year.

This will save you £537 on your energy bills, made up of £379 you won’t have to pay the National Grid, and £159 you can get by selling your excess power through the SEG.

However, if you could use this extra energy instead of selling it, you’d save an additional £132.

When do you break even on a solar battery?

You will break even on your battery after 23.95 years, assuming a three-bedroom house with a typical annual electricity consumption.

It takes this long because solar batteries are expensive, averaging at £4,500, and you’ll need to purchase two within the lifespan of your solar panel system.

However, electricity prices have risen sharply recently, and show no signs of slowing down, while the cost of solar batteries is decreasing all the time.

This means that in the near future, saving all the electricity you generate will be profitable.

What factors influence the return on investment?

There are a number of things that affect the ROI of solar batteries, including battery capacity, battery degradation, and the fluctuation of electricity prices.

• If your battery capacity is too small, you won’t be able to store as much electricity, which might mean you’ll end up using an unnecessary amount of electricity from the grid. Consider a battery with a bigger capacity if you live in a larger property.
• Battery degradation impacts ROI too — the faster a battery’s degradation, the sooner you’ll have to buy another one. Some batteries, such as the Tesla Powerwall, have low degradation rates that allow them to be used again and again with little issue.
• Fluctuating electricity prices change how slow or fast the ROI of your battery is. When prices for electricity are lower, the ROI on a solar battery decreases, because it becomes more affordable to use electricity from the grid. Higher grid electricity prices make storing your own energy in solar batteries much more worthwhile.

Solar batteries vs the Smart Export Guarantee

You can still sell excess electricity to the grid via the Smart Export Guarantee with solar batteries, but it’s better to save the electricity for later instead. 

This is because the current rate of grid electricity is 27.35p per kWh, and the best UK-wide SEG rate is 12p per kWh, so it makes more financial sense to store the energy rather than sell it.

Should you get a lithium-ion or lead-acid battery?

You should get a lithium-ion battery if you’re serious about adding energy storage to your home, because it’s almost always the better option. Lithium-ion batteries last longer, are far safer, and are more cost effective.

That’s despite being more expensive than lead-acid batteries. You’ll pay less for a lead-acid battery, but the time it’ll take to degrade compared to a lithium-ion battery, means you’ll purchase two within the latter’s lifespan.

How popular are solar batteries in the UK?

With the number of people in the UK adopting solar panels increasing all the time, it makes sense that the number of people who own solar batteries is rising, too. Right now, there are over 1.2 million households using solar panels in the UK, according to the latest MCS installations data.

In contrast, the number of homes using solar batteries is currently only around 10,000. This might sound small, but when you factor in the average cost of a battery (between £4,000–£8000) and add it to the typical £7,026 cost for solar panels, it makes sense.

However, interest in solar batteries is definitely increasing. A survey in 2019 by Which.co.uk found that just 6% of solar panel owners had their own batteries, but 74% would consider buying one. This is up from the 2018 results, in which roughly 60% of respondents said they’d consider a solar battery.

If you’d like to see the best solar batteries on the market, take a look at our choices.

Summary

If you can afford them, solar batteries are a worthwhile investment for their convenience alone. They’re particularly good if you want a solar PV system to reduce the amount of electricity you buy to the bare minimum.

Unfortunately, the upfront cost of solar batteries will continue to put them out of reach for a while yet, but this is slowly getting better.

For now, the simple fact is that even when factoring in the savings from not buying grid electricity, solar batteries are expensive pieces of kit.

Solar panels, however, have an excellent return on investment, especially as 69% of people are likely or very likely to buy or rent a property with solar panels on it, according to our latest National Home Energy Survey.

For those ready to invest in a solar system, you can simply fill in this webform, and our qualified installers will get in touch.

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