As more households embrace solar panels to generate clean electricity, the next smart step is making sure that energy works harder for you. That’s where solar panel battery storage comes in, helping you store excess electricity for use when the sun isn’t shining.
What is solar battery storage?
Solar batteries store the electricity your panels generate during the day, so you can use it later at night, on cloudy days, or during peak energy times when grid electricity is more expensive. It’s a way to maximise your solar investment, reduce reliance on fossil fuels, and cut your energy bills.
How big are solar batteries?
Most home battery systems are about the size of a large suitcase, roughly 100cm x 60cm x 25cm. The capacity you need depends on your energy use and how much surplus electricity your panels produce. For example:
- Gas or oil-heated homes often use a 5kWh battery.
- Homes with heat pumps or electric heating may need a 9kWh battery or more.
Battery sizes typically range from 1 to 16kWh, and your installer can help you choose the right fit.
What do they cost?
Prices vary depending on size and brand, but a 5kWh system costs around £4,600. Installing batteries at the same time as your solar panels can save money, as installers can integrate both systems in one job.
Are they worth it?
For many homes, yes. Battery storage helps you:
- Use more of your own clean energy
- Reduce grid reliance and energy bills
- Improve your carbon footprint
However, upfront costs and space requirements mean it’s not right for everyone. Batteries also have a shorter lifespan than solar panels, typically 10 to 12 years, and some energy is lost when storing and retrieving electricity.
What happens when batteries are full?
If your battery is full, you can:
- Export excess electricity to the grid and earn money via a Smart Export Guarantee (SEG) – around £220/year in Great Britain
- Charge your electric vehicle (EV) or other devices
- Use smart tariffs to buy cheap electricity and store it for later
Some EVs even support bidirectional charging, letting you use your car battery to power your home.
Making the most of your solar setup
Battery storage is just one part of a smarter, cleaner energy system. You can boost your savings by:
- Using energy-efficient appliances
- Adopting energy-saving habits
- Combining solar with heat pumps or EVs
- Exploring smart tariffs for off-peak electricity
For more detailed guidance, Energy Saving Trust offers a helpful overview of solar panel battery storage, including costs, benefits, and installation tips.
Want to know if battery storage is right for your home? Get a free, personalised energy plan from Energywise to see how solar and battery storage could work for you, tailored to your home, lifestyle, and energy goals.