The UK has the most developed time-of-use electricity market in Europe. Octopus Energy alone runs millions of homes on tariffs that price power by the hour — and a home battery is the simplest way to exploit that spread. A 10 kWh battery on Octopus Go earns roughly £770-870 a year doing nothing but charging cheap overnight and discharging into the expensive evening peak. No solar required.
Two forces converged. First, dynamic and time-of-use tariffs went mainstream: Octopus Go, Agile, Flux and Intelligent Go now serve a huge customer base, and Tibber brings Nordic-style hourly pricing. Second, the spread between off-peak and peak is wide and predictable — overnight power is a fraction of the 4-9 pm peak. A battery is a set-and-forget machine that buys low and uses its own stored power when prices spike.
| Tariff | Off-peak | Peak | Spread | Annual save (≈10-11.5 kWh) |
|---|---|---|---|---|
| Octopus Go | ~9.5p (00:30-05:30) | ~33p | ~23p | £770-870 |
| Intelligent Octopus Go* | 8p (23:30-05:30, 6h) | ~34p | ~26p | £750-950 |
| Octopus Agile | 5-15p (variable) | up to 50p | variable | £250-700 |
| Octopus Flux (solar+battery) | 10-15p | 33-35p + 24-32p export | high | £400-700 |
| Economy 7 | ~14p | ~30p | ~16p | £350-450 |
*Intelligent Octopus Go requires a compatible EV and smart charger.
For most households Octopus Go is the sweet spot: a fixed 9.5p off-peak window long enough to fill a 10 kWh battery on a sub-3.6 kW inverter, and a predictable ~33p daytime rate. Set the charge timer once and it runs every night. Agile can earn more on volatile days (occasionally negative prices — you are paid to charge) but needs automation or active management. Flux is built for solar owners who also export at peak.
Formula: annual saving = (peak − off-peak) × usable kWh × efficiency × cycles/day × 365.
| Input | Value |
|---|---|
| Off-peak charge (Go) | 9.5p/kWh |
| Peak discharge | ~33p/kWh |
| Spread | 23.5p/kWh |
| Usable capacity | 10 kWh |
| Round-trip efficiency | × 0.90 |
| Cycles per day × 365 | × 1 × 365 |
| Annual saving | ≈ £773 |
Published installer figures for an 11.5 kWh battery on Go land at ~£870/year (Habo Energy, April 2026 rates), and the regional peak rate varies 32-36p across the UK — check yours. This is the energy arbitrage alone; backup value and avoided generator fuel add on top. Model your own numbers in our no-solar backup + arbitrage calculator.
A 10 kWh home battery in the UK installs for roughly £6,000-9,000 in 2026. Against ~£773/year of arbitrage saving, that is a payback of about 5-8 years; faster on Agile in a good year, slower on Economy 7. After payback, every year of the battery's 10-15 year life is pure saving — potentially £3,500-8,500+ net over the lifetime. Solar pushes both the saving and the payback further in your favour, but it is not the thing that makes the maths work.
NovaBESS HomeWall (wall-mounted 2.5 / 5.1 / 10.2 kWh, parallel to 15 units) and HomeStack (modular 5 kWh to 60 kWh) are LiFePO4 systems with CE/UKCA-ready certification and an EMS that charges from the grid on schedule and discharges into the evening peak — exactly what UK arbitrage tariffs require. Both run 5,000+ cycles (~$0.12/kWh-cycle lifetime cost). For UK installers, distributors and brand owners we supply through our OEM/ODM line, pairing with any hybrid inverter that supports grid charging and a smart meter.
Enter your load, hours and Octopus Go (or Agile) peak/off-peak rates — see the right capacity, annual saving and payback with no solar required. No email required to use it.
Open the free No-Solar Backup + Arbitrage calculator →Read the Australia deep-dive and the master peak-shaving guide for the full country comparison and the savings formula.
Australia Peak Shaving Guide → Master Guide →Yes, if you are on a time-of-use tariff. The UK has the most developed dynamic-tariff market in Europe — Octopus alone serves millions of households on Go, Agile and Flux. A 10 kWh battery on Octopus Go earns roughly £770-870/year in pure arbitrage (charging cheap overnight, discharging into the evening peak). No solar is needed; solar only adds free daytime charging on top.
For most households Octopus Go is the best balance: a fixed ~9.5p/kWh off-peak window (00:30-05:30) against a ~33p daytime rate — about a 23p spread. Intelligent Octopus Go extends the window to 6 hours at 8p (needs an EV). Octopus Agile is the highest-potential but most volatile: half-hourly wholesale prices that can hit 5p overnight or 50p at peak, occasionally negative. Economy 7 is widely available but its ~14p off-peak rate gives smaller savings (~£350-450/yr).
On a 10 kWh usable battery, one daily cycle: charge at 9.5p, discharge at ~33p, times 90% efficiency = about £2.12/day, or ~£773/year. Published installer figures for a comparable 11.5 kWh battery run ~£870/year. The saving scales with battery size and the exact regional peak rate (32-36p across the UK).
No. Arbitrage works on grid charging alone — the battery fills from cheap overnight power and discharges into the expensive evening peak. That spread pays the battery back on its own. Solar adds a second free charge source and lifts savings further (a 4kWp array plus battery can save £1,000-1,200/year), but it is not required to start. You can always add panels later.
Yes. NovaBESS HomeWall and HomeStack are LiFePO4 systems with CE/UKCA-ready certification and an EMS that supports scheduled AC grid charging in TOU mode — exactly what UK arbitrage tariffs require. They are available through UK distributors and our OEM/ODM line, and pair with any hybrid inverter that supports grid charging and a smart meter.
All tariff rates and saving ranges are indicative 2025-2026 published data for planning only. Octopus and other supplier rates, the Ofgem price cap and SEG export rates change periodically. Regional peak rates vary 32-36p across the UK. Confirm current rates with your supplier and verify inverter grid-charging support before relying on any saving estimate. NovaBESS product specs are as listed; request a tailored quote for your configuration.
Tell us your tariff, daily kWh and inverter — we'll size a CE/UKCA-ready HomeWall or HomeStack system with grid-charging logic and quote distributor or OEM pricing.
Request a Quote