If you already have solar panels — or you are planning an installation — one question comes up again and again: is it worth adding a battery? Battery storage lets you keep the solar energy you generate during the day and use it later, instead of exporting your surplus to the grid for a small payment. For many London homes the answer is yes, but it depends on how and when you use electricity.
What battery storage actually does
Solar panels generate the most power in the middle of the day, which is often when no one is home to use it. Without a battery, that surplus is sent back to the grid. A home battery captures it instead, so you can draw on your own stored solar power in the evening when demand — and grid prices — tend to be higher.
Who benefits most from a battery
Households that use a lot of electricity in the mornings and evenings usually see the strongest case for storage, because that is exactly when a battery comes into its own. If you are out during the day, a battery helps you actually use the solar energy you would otherwise export. Homes with electric vehicles, heat pumps or higher overall consumption often benefit too.
How batteries work alongside solar
During daylight, your panels power your home first; any excess charges the battery; and once the battery is full, the remainder is exported. After dark, your home runs from the battery until it is depleted, then falls back to the grid. The result is that you rely on imported electricity far less across a typical day.
Sizing: bigger is not always better
Battery capacity should match your usage and your solar generation. A battery that is too small misses out on storing surplus on sunny days; one that is too large may rarely fill up, which is money not working hard for you. The right size depends on your daily consumption, your roof’s output and your routine — which is exactly what a proper survey establishes.
What about power cuts?
Some battery systems can be configured to provide backup power during an outage, keeping essential circuits running. Not every setup includes this by default, so if resilience matters to you, it is worth raising at the design stage.
Costs and savings
Adding storage is an investment, and the payback varies by property, system size, usage, weather and your energy tariff — there is no single figure that applies to every home. Time-of-use tariffs can improve the case further by letting you charge the battery from cheaper off-peak electricity as well as from solar. A survey is the only way to get an accurate, tailored estimate for your situation.
Find out if storage suits your home
Battery storage is one of the most effective ways to get more value from solar panels in London — but only when it is sized and specified correctly. Book a free survey with Best Renewables Ltd and we will assess your property, your usage and your goals, then recommend whether a battery is the right next step.