How much can a home battery save per year in the UK?

An 11.5kWh home battery on Octopus Go can save around £870 per year. Savings come from charging at 9.5p/kWh overnight and avoiding ~33p/kWh daytime rates. Actual savings depend on your tariff, battery size, usage patterns, and region.

How long does a home battery take to pay for itself?

Typically 5-6 years on Octopus Go. After payback, you save around £870 per year for the remaining life of the battery. With a 10-15 year lifespan, that's £4,000-9,000+ in net savings.

Do home batteries save money without solar panels?

Yes. A home battery saves money through tariff arbitrage, charging from cheap overnight electricity and discharging during expensive peak hours. No solar panels are needed. You do need a time-of-use tariff with a meaningful off-peak/peak price difference.

How Much Can a Home Battery Save?

The maths

9.5p

Overnight rate
(Octopus Go)

~33p

Daytime rate
(Octopus Go, avg.)

~23p

Saved per kWh
(after efficiency)

~£870

Typical savings
(11.5kWh, per year)

Based on Octopus Go 12-month fixed tariff rates (April 2026). Daytime rate varies by region (32–36p). Check your region.

Savings by battery size

Battery Size	Daily Savings	Annual Savings	Payback (approx.)
5kWh	~£1.03	~£375	7-9 years
10kWh	~£2.07	~£755	6-8 years
11.5kWh (Habo Energy)	~£2.38	~£870	5-6 years
15kWh	~£3.10	~£1,130	6-7 years

These figures assume daily cycling and account for ~90% round-trip efficiency. Your actual savings depend on your usage patterns and tariff rates. For help choosing between tariffs, see our guide to the best tariffs for battery storage.

Key point: You don't need solar panels to get these savings. Tariff arbitrage alone, charging when electricity is cheap and using it when it's expensive, pays for the Habo Energy system in 5-6 years.

How the calculation works

Take the Habo Energy 11.5kWh battery on Octopus Go. The off-peak rate is 9.5p/kWh and the average daytime rate is approximately 33.5p/kWh. After accounting for ~10% round-trip losses, you get 10.35kWh of usable energy per cycle.

Cost to charge overnight: 11.5kWh x 9.5p = 109.25p

Value of stored energy at peak rate: 10.35kWh x 33.5p = 346.7p

Daily saving: £3.47 - £1.09 = £2.38

Annual saving: £2.38 x 365 = ~£870

Savings vary by region because the Octopus Go daytime rate ranges from 32p to 36p across the UK. Check your region's exact rate.

Savings by tariff

Tariff	Off-peak rate	Peak rate	Annual saving (11.5kWh)
Octopus Go	9.5p	~33p	~£870
Intelligent Octopus Go (requires EV)	8p	~34p	~£950
Economy 7	~14p	~30p	~£550

What about after payback?

Once your battery has paid for itself, typically in 5-6 years, every year after that is pure savings. With a battery lifespan of 10-15 years, that's potentially 4-10 years of ~£870 savings. On an 11.5kWh system, your total net savings over the battery's lifetime could reach £3,500-8,500+. For a detailed breakdown of upfront costs, see our home battery storage cost guide. For an overview of how the systems work, see our complete guide to home battery storage systems.

More savings with solar

If you have solar panels, savings increase further. Instead of exporting surplus solar electricity to the grid at 4-5p/kWh, your battery stores it for evening use, effectively valued at ~33p/kWh. A typical 4kWp solar array combined with an 11.5kWh battery can save £1,000-1,200 per year.

But you don't need solar to start. A battery-only setup delivers strong returns on its own, and you can always add solar later. For a full cost-benefit analysis, see is battery storage worth it?

Want to see your exact numbers? Use our savings calculator to enter your tariff rates and battery size for a personalised estimate.

Start saving ~£870 per year

Reserve your Habo Energy battery with a refundable deposit.

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