Solar Batteries & Storage Systems

With the current state of energy prices, it makes more sense now than ever to invest in solar panels.

Solar panels convert sunlight into free electricity that’s all yours and that you can use in your home. Over time, what you save on your electricity bills will make solar panels an investment that saves you money.

Solar panel systems come in various shapes and sizes. One extra feature that many solar panel systems have is a solar battery. Solar batteries used to be more something for people who were mainly interested in being environmentally friendly and ‘living off the grid’. They still mean you don’t need the grid and that you’ll be helping the environment, but nowadays they’re a serious financial investment as well.

The average cost of a solar battery is around £4,000.

Over time, a solar battery could increase the total amount you save from having solar panels. However, whether they’re the right thing for you depends on a few things, and you need to think before you invest.

At Solar Panel Savers, we’ll help you work out whether solar batteries are right for you. We’ll look at:

How much solar batteries cost
How to work out if you should get a solar battery
Some other things you might want to know

What is the Point in Having a Solar Battery?

Batteries obviously store energy. Solar batteries do the same thing, but they store energy when your solar panels are producing more electricity than you’re using in your house.

They do this because it makes good financial sense.

Daytime Electricity Production

One thing that can be a problem with solar panels is that they only produce electricity during the day when the sun’s shining. If no one’s at home or there are no appliances running to use this daytime electricity, then the excess energy will be exported to the grid rather than used in the home.

Don’t You Get Paid for Exporting Electricity to the Grid?

Yes, you can get paid for exporting electricity to the grid if you don’t use it yourself. The problem is that you get paid less for exporting electricity to the grid than you pay to buy electricity from the grid. As a result, it makes economical sense to use as much of the electricity you produce as possible.

This is where a battery could come in. With a battery you can store excess electricity and use it yourself rather than sell it to the grid. Most often people install solar batteries when they’re out of their house during the day. The battery simply stores the excess daytime energy, ready for them when they get home in the evening.

Are There Other Ways a Solar Battery Could Be Useful?

A solar battery could be useful for more than just dealing with the problem of excess solar panel energy production.

You might also be able to use a solar battery to store energy from the National Grid when prices are lowest. If you’re charged more for electricity at peak times, then installing a solar battery could mean that you’re able to store grid energy when it’s cheapest. In fact, solar batteries are sometimes installed by people who don’t even have solar panels.

As well as this, it may even be possible to get paid by energy companies to store electricity when the National Grid produces too much. Energy companies have the same problem as solar panel owners, and at certain times they produce excess energy. With a battery it may be possible to get paid by energy suppliers to store excess electricity from the grid at these times.

Please note that you may need permission before you can install a battery that takes electricity from the grid.

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How Much Do Solar Batteries Cost?

As we said earlier, the average price of a solar battery is £4,000. They’re always a significant investment. They do, however, vary a lot in price. Cheap batteries are around £1,500 and expensive batteries can cost as much as £11,000.

The Important things to consider are:

What storage capacity will suit the energy demands of your household
Which battery will offer you the greatest return on your investment

Here are the prices and some details on some of the most popular solar batteries in 2023:

Solar Battery	Capacity	Estimated Price (Without Installation)	Warranty Period	Additional Info
Enphase AC Battery	1.2 kWh	£1,550	All these solar batteries come with a 10 year warranty	Ideal for a small flat
SolaX 3.3	3.3 kWh	£3,300		3.3 kWh – £3,300
Duracell Energy Bank	3.3 kWh	£4,500		Comes looking like a duracell battery and has some other nice features
Powervault 3	4 kWh or 8 kWh	£3,230 or £5,000		Two capacity choices
Nissan XStorage	6 kWh	£3,500		Bonus capacity
Tesla Powerwall	13.5 kWh	£11,000		Future level output

Please note that in some cases there may be a difference between the stated capacity and the usable capacity. Make sure that you check carefully before deciding on which solar battery to buy.

Solar Battery Pros and Cons

Here’s a simple breakdown of the pros and cons of installing a solar battery with your solar panel system.

Pros

Reduce your monthly energy bills
Save even more money in the long term
Always use your own electricity
Help the environment
Take advantage of National Grid electricity at cheap rates
Earn extra money for storing excess grid energy

Cons

Increases the initial cost of your solar panel investment
Will not save you money if you use daytime solar panel energy rather than store it with your battery
Your battery will probably need replacing during the lifetime of your solar panel system
You may need to buy a new inverter if you have an old solar panel system

Should You Get a Solar Battery?

You don’t have to buy a solar battery, but it might be a good idea.

Purchasing and installing a solar battery with a solar panel system will add to the initial cost of your investment. You need to weigh things up first and make sure that you need a solar battery before you invest in one. The most important thing to think about is how much of the daytime electricity your solar panels produce you’ll be able to use. A good basic rule is:

If you can use most of the daytime electricity that your solar panels produce then you probably don’t need a solar battery. Otherwise, it may be worthwhile investing in one.

If you think that it might be sensible to invest in a solar battery so you can store your excess daytime electricity, then you need to estimate how much money you’ll save.

How Much Money Will I Save?

At this point, it’s probably a good idea to speak to a solar panel expert to get some advice on whether or not you should invest in a battery. The best thing is to predict as accurately as possible whether a solar battery will offer a good return on investment. A solar panel expert will be able to talk you through your personal situation and offer advice that’s unique to you.

You might, however, be able to get a good picture by considering the main factors that will affect whether a battery is a good investment.

As such, the amount of money you can save with a solar battery depends on:

How much your solar battery costs (including installation)
How much you’ll save on your energy bills
How long your battery lasts

If you know what battery will suit your household’s energy uses, how long it will last and how much energy you’ll draw from it, then you may be able to predict how much you’ll save each year from having a solar battery.

One thing to Note that a great deal of uncertainty surrounds energy prices. Energy prices are higher now than they’ve ever been, and it looks like high prices will remain. The Energy Price Guarantee will, in fact, increase from April 2023 to £3,000. It will also stay at this amount for 12 months. It may well be that investing in a solar battery turns out to be an even better investment than you anticipate if there are more rises in energy prices in the future.

The Energy Saving Trust offer some good advice on whether home energy storage (including with solar batteries) is a good idea on their website.

Commonly Asked Solar Battery Questions

Here are some of the common questions people have about solar batteries.

Are there other ways to use excess electricity?

Yes. Another way people often make use of excess daytime electricity produced by their solar panels is with a diverter.

A diverter (as the name suggests) is a device that diverts, or redirects, electricity. If your solar panel system produces excess energy, a diverter will divert the excess energy away from the grid. Rather than sending the excess energy into the grid, the diverter will divert it into an appliance in your house. That way, you’ll make more efficient use of the energy your solar panels produce.

Usually, diverters divert energy into an immersion heater and are used to gain free hot water from excess solar panel energy.

What capacity battery do I need?

Rather than just getting the biggest battery you can, you need to find a battery that suits your energy needs and your solar panel system. Your solar battery needs to cover your energy demands without being too big for your solar panels to charge. After all, there’s no point having a large battery if your solar panels can’t charge it.

How long will a solar battery last?

The lifetime of a solar battery is important as this will help determine whether it’s a good investment or not. You can base your estimate of how long a battery will last on the warranty that’s offered with it. However, it may also be a good idea to do some research and try and find one that will outlast its warranty.

The longer a battery lasts, the more money you’ll save from your solar panel system, overall. Most batteries will need replacing within the lifetime of a solar panel system. However, some may need replacing twice. It’s best to avoid batteries that will need replacing twice in order to maximise your savings.

One point to note is that the lifetime of a solar battery may depend, in part, on how well you care for it. Some advice on solar battery care and maintenance can be found here.

Are there different types of solar battery?

There are two basic types of solar battery:

Lithium-ion
Lead Acid

Put simply, lithium-ion batteries are better. They’re more expensive, but it’s usually worth the investment. If you want to find out more, have a look at this article here.

Can I pay for my battery on finance?

There are finance options available for purchasing solar batteries. Beware, though, that you’ll need to factor in the cost of borrowing into your overall solar battery savings estimate. The amount of interest you pay will need to be included as part of the total cost of your solar panel system.

Do I need to pay VAT on my solar battery?

Thanks to the government’s 0% VAT on energy saving products scheme, until 2027, you may not need to pay VAT on your solar battery.

If you install your battery at the same time as you install your solar panels, then you won’t need to pay any VAT
However, if you fit your solar battery after your solar panels, you’ll need to pay VAT

How big are solar batteries?

Solar batteries vary in size according to their capacity.

Small batteries, like the Enphase AC Battery, are about the size of a briefcase. They’re usually wall mounted and can fit under the stairs or up in your attic. Large batteries, like the Tesla Powerwall, are quite a bit larger. Tesla Powerwalls sit against the wall on the ground and usually need to go outside or in a garage. Tesla Powerwalls measure 115.1cm x 75.2cm x 14.6cm.

Do I need a special inverter for a solar battery?

An inverter is a crucial part of your solar panel system. To find out what an inverter is, have a look at our article here.

You’ll need to have an inverter that supports your solar battery. This is easily done if you install your solar battery when you install the rest of your solar panel system. Your installer will fit an inverter that works with your battery.

In some cases, where people fit a battery to an old solar panel system with an incompatible inverter, they will need to replace the inverter at the same time. If you are building your solar panel system without a battery, but will fit one later, then you need to be careful. If this is the case, make sure you fit an inverter that will support your future battery.

Will a solar battery give me back up power if there’s a power cut?

This may seem like an obvious benefit. However, actually, not all solar batteries will give you back up power if there’s a power cut. Some solar batteries won’t give you any back up if there’s a power cut and some will only give you a limited supply. In any case, it’s unlikely that any solar battery will give you full power for the duration of a power cut.