British Gas Store&Save vs Store&Reward: the real cost

British Gas and Sunsave have launched two unusual battery-only tariffs. Instead of adding a cheap overnight window to a normal electricity tariff, they pair a professionally installed 10kWh battery with a flat electricity price and let British Gas manage when the battery charges and discharges.

That simple headline hides a long decision. The tariff is fixed for two years, while Sunsave's illustrative finance lasts for 10 years. You also give British Gas control of the battery and must fit a narrow eligibility profile. The right comparison is therefore not only 11p versus 22p. It is the full battery, tariff and household setup over time.

The two tariffs at a glance

These headline rates were shown on the British Gas home-battery tariff page on 18 August 2026. British Gas's postcode tariff-information tool also listed several Store and Save and Store and Reward July 2028 variants for a London sample postcode. All showed the same 11p or 22p electricity unit rate, with regional standing charges and a £75-per-fuel exit fee. Prices, standing charges, eligibility and product availability can change, so use your own quote and tariff information label as the final check.

Store&Reward covers only the first 24 monthly payments

The £37.50 monthly credit sounds like it covers the battery. For the first two years it matches the monthly payment in Sunsave's representative finance example. Twenty-four credits total £900. The example finance is 120 monthly payments of £37.50, totalling £4,500, including interest on a £3,628.45 loan.

That leaves eight years of example payments after the tariff credit ends. The tariff itself also needs a new decision after its two-year fixed period. Store&Reward may still suit a household that values lower early outgoings, but it should not be described as a battery paid for by British Gas for the full finance term.

Sunsave also lists a £3,629 upfront option and says customers own the battery from installation. Finance is subject to status. Compare the cash price, interest, early repayment terms and any future tariff before counting the bill credit as a saving.

Who is actually eligible?

Store&Save and Store&Reward are not general battery tariffs for any home. British Gas says they are for a new battery-only installation through Sunsave. Its current eligibility list requires:

• no existing home battery
• no solar panels, EV charger or heat pump
• no export tariff or Smart Export Guarantee arrangement
• annual electricity use between 3,100kWh and 4,100kWh
• a smart meter sending half-hourly readings
• payment by fixed Direct Debit
• permission for British Gas to manage charging and discharging

Sunsave's own page currently gives a wider upper usage limit of 4,500kWh. That conflicts with the stricter British Gas figure, so treat 4,100kWh as the safer public limit until your quote confirms otherwise. This is exactly the sort of detail that should be settled in writing before signing a battery contract.

Homes with solar, an EV charger, a heat pump or an existing battery should look at a different route. British Gas points those customers towards Charge Power, while Octopus customers can compare their existing tariff and battery routine using our battery-only storage guide.

What giving British Gas control means

British Gas says it will manage the battery schedule on both tariffs. That can remove daily tariff admin, but it also means the supplier's control logic becomes part of the product. Ask what reserve level is kept, how the system behaves during an outage, what happens if broadband or the smart meter stops communicating and whether you can temporarily override the schedule.

The current Sunsave page says the package does not provide backup power. It also says Store&Save and Store&Reward cannot be combined with an export tariff. The battery is therefore being used to shift grid electricity for the household, not to sell stored energy back to the grid or keep the home powered during a cut.

Check the quote, not only the tariff headline

The Sunsave page currently contains a confusing FAQ entry that reverses the Store&Save and Store&Reward descriptions. The main British Gas tariff page, its tariff-information tool and the main Sunsave product sections consistently identify Store&Save as 11p anytime and Store&Reward as 22p anytime with the monthly credit. Use the formal quote and tariff label rather than relying on one FAQ summary.

The practical verdict

Store&Save is the simpler bill calculation: a low flat unit rate, a standing charge and the separate battery cost. Store&Reward reduces the first two years of cash outgoings, but the electricity rate is higher and the battery payments continue after the credit stops. Neither option should be chosen from the tariff rate alone.

Start with the ten-year battery cost and your real electricity use. Then check whether you are happy with supplier control, no export tariff, no backup power and a new tariff decision after two years. If you already have an EV, solar panels, a heat pump or other smart technology, these two products are not designed for your setup.

If that wider comparison leads you back to Octopus, check the current tariff and eligibility first. Our referral page is there only after Octopus still fits the home.