Is home battery storage worth it without solar panels?

Can you have a home battery without solar panels?

Yes. MCS, the certification scheme for battery installers, says a battery on its own can be charged overnight on cheaper off-peak tariffs and used when prices are higher [2]. A standalone battery for storing electricity from the grid, installed in a home, is zero-rated for VAT until 31 March 2027, then 5 per cent [18]. Octopus Energy, for example, says it can install a stand-alone battery for most homes, subject to the network operator's approval [10].

The tariff is the catch. A battery without panels earns nothing on a single-rate tariff: the Energy Saving Trust found no savings under a standard tariff [1]. Some of the cheapest overnight tariffs are closed to a home with only a battery: Intelligent Octopus Flux needs solar panels [6], Octopus Go an electric car charged at home [7], and Cosy Octopus a heat pump, electric radiators or an electric boiler [8]. Others are open to it: dynamic tariffs such as Agile Octopus, which needs a smart meter [4]; Economy 7; and battery tariffs such as British Gas Charge Power, which needs a home battery, with or without solar, a smart meter and British Gas supply, and gives half-price electricity from midnight to 5am [9]. The sums below cover Agile and Economy 7.

Would a new tariff save money without a battery?

Check this first, because the tariff can save or cost money before any battery is bought. On Agile Octopus the price changes every half hour with the wholesale market and is capped at 100p per kWh [4]. Over the year from 1 October 2025 to 30 September 2026 in London it averaged 19.0p across the day, excluding VAT, against 24.7p on Octopus's London single rate over the same year [3][5], but 33.2p between 4pm and 7pm and 22.0p from 7pm to 10pm. Whether the tariff alone saves depends on how much of your use falls in those hours; use moved to cheap hours costs less.

Economy 7 works the other way round. Over the same year Octopus's London day rate averaged 30.9p, 6.1p more than its single rate of 24.7p, and the night rate 13.0p, excluding VAT [5]. Without a battery, it pays only if enough of your use already falls at night. The Energy Saving Trust notes that shifting use to off-peak times would raise savings on any time-of-use tariff; its modelling assumed no change in habits [1].

How much does a battery without solar save?

The battery's own saving is the price gap it can use, less what is lost charging and discharging. The answer depends on what you compare with. Over the year of Agile prices above, each kWh moved out of 4pm to 7pm into the cheapest 3 hours before 4pm was worth about 20.0p against staying on Agile without a battery, but 11.5p against staying on the single rate, by our calculation. On Octopus's Economy 7 the same comparison gives 16.4p and 10.2p. All allow for the 90 per cent round-trip efficiency on one maker's datasheet [3][5][12].

The Energy Saving Trust, using tariffs on the market on 1 April 2024 and 2024 half-hourly prices for the dynamic tariff, found a median saving of about £320 a year for a battery plus a dynamic tariff in a gas-heated home with no solar, and £250 with Economy 7, both against staying on a standard tariff [1]. Those figures include the effect of the tariff switch as well as the battery.

When is a battery without solar not worth it?

At these prices and usage levels, repayment within a battery's life looks difficult. The Energy Saving Trust put the payback at around 20 years on its best tariff, against a battery life it assumed to be 10 years [1]; its advice page gives about 10 to 12 years as a typical life [16]. In our table, moving 6 kWh a day out of the Agile peak every day is worth about £440 a year against staying on Agile, so the battery would need to cost under about £4,400 to repay in 10 years, or £5,200 in 12. Moving 6 kWh a day takes about 6.7 kWh of nominal capacity; our calculation from the government's median rate for batteries of 6 to under 11 kWh puts that at about £5,900 [17]. To repay that, each kWh moved would need to be worth about 27.1p over 10 years or 22.6p over 12, against the 20.0p it was worth over this year. A cheaper quote, more use in the dear hours or a wider price gap would change the answer, so check your own figures. The case is weakest when:

• You stay on a single-rate tariff. There is no cheaper time to charge, so no saving [1].
• Little of your use falls in the dear hours. A battery can only replace electricity you would otherwise buy at the high price.
• The quote is at or above the median. Repaying in 10 years needs a tenth of the price saved each year, so a higher quote raises the bar in step.

A first estimate before any quote: from your smart meter's half-hourly data, find how many kWh your home uses between 4pm and 7pm on a typical day. That, times 365, times the value per kWh above for your baseline (20.0p if you would be on Agile anyway, 11.5p if you are on the single rate), estimates the saving from replacing those peak-period imports. A battery can also replace imports at other dear times (7pm to 10pm averaged 22.0p on Agile), so a full estimate needs your whole half-hourly use and a charging schedule; the battery planner works through that. Moving washing and dishwasher cycles to cheap hours costs nothing and counts first.

Is a battery without solar worth it for power cuts?

Backup is a separate reason to buy. Where a battery needs network approval under G99, one set up to run the house in a power cut cannot use the fast-track route; the standard G99 process applies [20]. Whether that is worth paying for depends on how often you lose power and what you need to keep running; it is not part of the savings above. The power cut guide covers the set-up.

What does a battery without solar cost?

A 5 kWh battery works out at about £6,500 installed and a 10 kWh battery about £8,900, by our calculation from the government's 2025-26 median price per kWh of nominal capacity for each size band. Those figures cover batteries in existing homes with and without solar panels, and leave out the panels themselves [17]. The Energy Saving Trust used £6,200, a mid-range installed cost for a standard domestic system, in modelling a home with a 9 kWh battery [1]. A battery on its own is connected under the same network rules as any generator: up to 16 amps per phase (3.68 kW on a single-phase supply) the installer fits it and tells the network operator; above that, the G99 process comes first [19]. These are the Great Britain rules; Northern Ireland has its own, G98/NI and G99/NI [14]. Prices by size are on solar battery costs.

What if you have a heat pump or an electric car?

The sums change, because heat pump and electric car tariffs open up cheaper overnight rates, and there is more use to move. The Energy Saving Trust found batteries "better paired with heat pumps than with solar panels" on the right tariff [15]. Is a solar battery worth it covers homes with panels, and the battery planner works through your own tariff and use.