Energy storage systems let you capture heat or electricity when it’s readily available,. This kind of readily available energy is typically renewable energy. By storing it to use later, you make more use of renewable energy sources and are less reliant on fossil fuels.
Let’s look at how they work and what the different types of energy storage are.
Home energy storage systems store generated electricity or heat for you to use when you need it.
You can store electricity in electrical batteries, or convert it into heat and stored 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 already generate your own renewable energy, as it lets you use more of your low carbon energy. It reduces wasted energy and is more cost effective than exporting excess electricity.
Depending on your setup, you might benefit from one or more of these energy storage systems:
Electric batteries help you make the most of renewable electricity from:
For example, you can store electricity generated during the day by solar panels in an electric battery. You can use this stored electricity for powering a heat pump when your solar panels are no longer generating electricity.
Battery storage tends to cost around £5,000 to £8,000, but will depend on:
You may also want to plan around future electricity use if you’re intending to buy an electric vehicle (EV) or heat your home with a heat pump.
You can use a battery to store electricity you import from the grid at cheaper times of the day, with a smart time of use tariff. This can reduce your reliance on more expensive electricity during peak periods, with some tariffs even letting you sell energy during those periods.
Thermal stores are highly 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 spare heat or electricity, often generated by renewable energy systems. These store heat in a material that changes from a solid to a liquid. These materials are called phase change materials (PCM).
Spare heat or electricity charges the PCM inside the heat battery. When the heat is needed, the material changes back into a solid with a release of heat, which is used to provide hot water.
Heat batteries are generally smaller and lighter than filled thermal stores. This means you can install one in a convenient location even if you can’t find space for a traditional hot water cylinder.
Heat storage batteries don’t degrade in the same way as electrical batteries, so should have a longer lifespan.
Excess electricity generated can be used later, or elsewhere in your home. This reduces the amount of energy that’s wasted.
Being able to use your own stored energy means you don’t have to import energy from the grid, saving you money.
For example, you can store energy while your solar panels are generating electricity, then sell it to the grid during peak periods.
Making the most of clean, renewable energy lowers how much carbon dioxide your home emits.
Depending on the kind of energy storage you install, you could see savings on your energy bills.
If you have a renewable electricity generator like solar panels or a wind turbine, installing energy storage will save you money on your electricity bills.
You need to weigh the potential savings against the cost of installation and how long the battery will last. Energy storage technology is constantly evolving, and new batteries will last longer as the technology improves.
When you speak to an installer, ask them to about the energy storage lifespan and cost savings, to make sure you understand fully before committing to anything.
Thermal stores and thermal batteries aren’t specifically designed to save money. It’s better to think of them as products that will solve problems or allow 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 would describe a hot water cylinder as something that specifically saves money.
First, work out what kind of energy storage is best suited to your home.
For England, Wales and Northern Ireland, use our Go Renewable tool to find recommended energy solutions for you.
For Scotland, visit our home renewables selector tool.
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: 1 October 2024