Quick answer
A home battery stores electricity from solar panels or the grid for use when needed. It can reduce bills and provide backup power during outages.
A home battery system stores electricity so you can use it when your solar panels are not generating — in the evenings, overnight, or on cloudy days. You can also charge it from the grid during cheap off-peak hours (like overnight on an Economy 7 or Octopus Go tariff) and use it during expensive peak hours. Most home batteries store between 5kWh and 15kWh — enough to cover a typical household's evening and overnight usage. Popular brands in the UK include Tesla Powerwall, GivEnergy, SolarEdge, and Solis. A battery system typically costs £3,000–£6,000 installed and qualifies for 0% VAT. It will not power your whole house during a grid outage unless specifically designed to do so (check for islanding capability).
Need more detail? Choose a view: