Energy storage systems let you store heat or electricity so you can use it later.
They often work alongside renewable technologies like solar panels, helping you use more of the energy your home generates instead of relying on fossil fuels.
An energy storage system also lets you use low-cost electricity when it’s available by:
Let’s look at how they work and what the different types of energy storage are.
In November 2025, the UK Government expanded the Boiler Upgrade Scheme to include heat batteries.
If you’re eligible, you can get £2,500 off the cost of installing a heat battery to work with your central heating system.
This is in addition to a consultation on alternative heating systems, such as storage heaters and infrared heating.
Energy storage systems store electricity or heat for you to use when you need it.
You can store electricity in electrical batteries or convert it into heat and store it in a heat battery. You can also store heat in thermal storage, such as a hot water cylinder.
Energy storage can be useful if you generate your own renewable energy. This is because it lets you use more of your low carbon energy, which is more cost effective than exporting excess electricity.
Energy storage can also help you make the most of a smart ‘time of use’ tariff, where the price of electricity varies throughout the day and night.
Often this means using electricity during the night when electricity is cheaper and giving out heat during the daytime when prices are more expensive.
Battery storage helps you make the most of renewable electricity from:
For example, you can store electricity generated during the day by solar panels in a battery. You could then use this stored electricity to power a heat pump in the evening, when your solar panels aren’t generating electricity.
Battery storage systems typically cost around £5,000 to £8,000. The amount of storage you need depends on:
You may also want to plan around future electricity use. For example, if you’re intending to buy an electric vehicle (EV) or install a heat pump.
Water based thermal stores are insulated water tanks that can store heat as hot water for several hours. They usually serve two or more functions:
Thermal stores can vary in size but tend to be between 250 and 500 litres
Heat batteries store energy as heat provided by:
Heat batteries can heat hot water for your central heating or your taps. You can also use some heat batteries as a thermal store within a central heating system, typically alongside a heat pump.
There are two types of heat batteries that store energy in different ways.
One type stores heat in a material that changes from a solid to a liquid and back. These materials are called phase change materials (PCM).
Spare heat or electricity charges the PCM inside the heat battery. When you need the heat, the material changes back into a solid, releasing heat for your heating and hot water.
The other stores heat in a material such as a ceramic where there’s no phase change. It releases the heat when it’s needed for your heating and hot water.
Heat batteries may have a longer lifespan than electrical batteries.
If you live in England or Wales and are eligible, you can get £2,500 off the cost of a heat battery installation. For more information, read our guide to the Boiler Upgrade Scheme.
If you have a renewable electricity generator like solar panels, installing energy storage may save you money on your electricity bills.
In the case of electrical battery storage you need to weigh the potential savings against the cost of installation and how long the battery will last.
Heat batteries may last longer, but whether they’ll save you money depends on how you currently heat your home.
When you speak to an installer, ask them about the energy storage lifespan and how much you’re expected to save on your bills. This will make sure you understand fully before committing to anything.
Thermal stores and heat batteries aren’t specifically designed to save money. It’s better to think of them as products that will solve problems or let other technologies work more efficiently.
For example, you can’t have a solar thermal system without either a hot water cylinder or a thermal store. But not many people would describe a hot water cylinder as something that specifically saves them money.
Once you know what you need, we recommend getting quotes from at least three different installers. These should have certification by the Microgeneration Certification Scheme, which ensures installers work to a specific standard. This makes sure you’re getting value for money.
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Last updated: 22 May 2026
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