0% VAT on installed solar and batteries ends 31 March 2027. Prices checked October 2026. How it works
Broadstairs Solar BatteryBroadstairs, Thanet, Kent · CT10 07763 100477

Home / Guides / Is a home battery worth it with the SEG?

Batteries

Is a home battery worth it with the Smart Export Guarantee?

Last reviewed 7 October 2026. Written for Broadstairs, Kent. Figures are estimates, not quotes.

Short answer. Often not on savings alone. A 5 kWh battery with solar and a 12p export rate adds about £190 a year in our model, so payback is long. It looks better in an evening-heavy home, with an electric car, or on a cheap overnight tariff.
White wall-mounted home battery beside a consumer unit with neat grey conduit on a brick garage wall
In this guide

The sums in plain words

Without a battery, spare solar power is sold at your export rate. With one, you keep it and use it later instead of buying at about 26p (the Ofgem cap is 26.32p per kWh from 1 October to 31 December 2026). Losing about 10% on the way through the battery, each stored unit is worth about 23.7p to you.

Against a 12p export rate, that is a gap of about 11.7p. Our model fills a 5 kWh battery on about 190 days a year, storing around 950 kWh, so the gain is roughly £110 a year (our arithmetic). Set against a price of £2,750 to £4,750, that is why payback runs long.

With an 18p export rate the gap falls to about 5.7p, and the same battery adds only about £55 a year (our arithmetic). A generous export rate makes a battery less valuable, not more.

When a battery makes more sense

  • You are out in the day and use power in the evening.
  • You have an electric car or a heat pump.
  • You can charge cheaply overnight on a smart tariff. At an example 10p cheap rate, a 5 kWh battery added to solar could save about £180 to £280 a year on our model.
  • You want backup for key circuits, which often costs extra.
  • You value needing the grid less.

The Energy Saving Trust says a battery lasts about 10 to 12 years, shorter than panels, and that savings will not always justify the cost on their own.

How to decide

Put your own bill and your own export rate into our estimator. If the payback is longer than the battery's life, buy one only if you value the other benefits.

Questions people ask

What is a good SEG rate?

The rates we opened in October 2026 ranged from 4.1p to 18p. Our Smart Export Guarantee guide lists each with its conditions.

Can I switch SEG supplier?

Often yes, though some higher rates are tied to the supplier that fitted your system.

Do I get SEG with a battery on its own?

SEG pays for power you generate. A battery charged only from the grid does not generate. EDF lists a battery-only route that needs an MCS or Flexi-Orb certificate, for its own customers.

Want numbers for your own home? Try the estimator or ask for a free quote.

Sources

More guides

Get a free, no-pressure quote

Tell us your address and your last 12 months of electricity use. We reply with clear options and prices.

Request a free quoteWhatsApp usCall 07763 100477
Call usWhatsApp us