What Is Battery Arbitrage?
Battery arbitrage means charging your home battery when electricity is cheap and discharging (using) it when electricity is expensive. With the right time-of-use tariff, the price spread between cheap and peak electricity in the UK in 2026 can reach 30–40p per kWh. On a 10kWh battery cycled once daily, that represents £1,095–£1,460 in annual value — before any solar generation is factored in.
The Main UK Time-of-Use Tariffs in 2026
Octopus Energy: Agile
Octopus Agile is the UK's most dynamic tariff. Prices change every 30 minutes based on wholesale electricity market prices, set a day ahead. In 2026:
- Off-peak periods (typically midnight–06:00): 3–8p/kWh is common; prices occasionally go negative (Octopus pays you to use electricity)
- Standard daytime: 15–25p/kWh
- Peak periods (16:00–19:00): 30–60p/kWh, occasionally higher during grid stress events
Agile works best with battery automation. Systems like GivEnergy's AIO with the Agile integration, or Sonnen's API-connected units, automatically charge when prices dip and discharge during peaks — without manual intervention.
Octopus Energy: Flux
Octopus Flux is a closed-loop tariff designed for solar and battery homes. It offers:
- Cheap overnight import: Fixed at approximately 16–18p/kWh (midnight–05:00)
- Standard daytime import: approximately 24–26p/kWh
- Peak daytime import: approximately 30–35p/kWh (07:00–09:00, 16:00–19:00)
- Export during peak hours: approximately 15p/kWh via the bundled Outgoing Flux export tariff
Flux is simpler than Agile — fixed time bands rather than half-hourly price signals — making it easier to programme a basic battery schedule. Many homeowners find it more manageable than tracking Agile's volatile prices.
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EDF Energy: EV and Smart Tariffs
EDF Energy's GoElectric tariff (originally aimed at EV drivers) includes off-peak rates of 7–9p/kWh between 00:00 and 07:00, making it suitable for battery arbitrage alongside solar. EDF's variable export product can also complement battery arbitrage strategies by timing exports to higher-value periods.
British Gas: PeakSave and Hive Integration
British Gas offers demand flexibility payments through its PeakSave scheme, where customers with compatible Hive systems receive credits for reducing consumption during grid stress events (typically called by National Grid ESO). This is not continuous arbitrage but provides useful supplementary income.
Setting Up Battery Arbitrage: What You Need
| Requirement | Details |
|---|---|
| Smart meter (SMETS2) | Essential for half-hourly metering and tariff eligibility |
| Compatible battery system | GivEnergy, Sonnen, Tesla Powerwall 3, SolarEdge, Sungrow |
| Octopus Energy account | Agile and Flux are Octopus-exclusive products |
| Battery management app | GivEnergy portal, Tesla app, Sonnen app |
| Automation (optional) | Zappi integration, HEMS platform, or API-based scheduler |
Real Savings Calculation: A South-East England Example
Property: 4-bedroom detached, 8kWp solar, 9.6kWh GivEnergy battery, Octopus Flux tariff
Overnight charging savings:
- 9.6kWh charged at 17p (off-peak Flux rate) vs 27p (standard rate)
- Saving: 10p/kWh x 9.6kWh = 96p per night
- Annual overnight charge saving: £350
Peak period self-discharge savings:
- Discharging 9.6kWh during peak period (33p/kWh) instead of importing
- Value per cycle vs daytime charging: ~9p/kWh premium x 9.6kWh = 86p per night
- Annual peak discharge value: £315
Solar self-consumption addition:
- Solar surplus charged to battery rather than exported, then used instead of peak import
- Estimated additional value: £450–£600 per year
Total estimated annual benefit: £1,100–£1,265
Automation: Making It Work Without Constant Monitoring
Manually switching your battery between charge and discharge modes every day is impractical. In 2026, automation options include:
→ Before you read on — see what payback looks like for your roof in under a minute.
- GivEnergy + Octopus Agile integration: GivEnergy's portal can access Agile prices via API and automatically set charge windows for the cheapest half-hour slots each night.
- Tesla Powerwall 3 + Energy Plan: Tesla's UK Powerwall app integrates with select tariffs to optimise charge/discharge scheduling.
- Home Assistant: Open-source home automation software with Octopus Energy and battery integrations is popular among technically minded homeowners. The /octopus_energy integration pulls live Agile prices; combined with GivEnergy or Sungrow battery control, it enables fully automated arbitrage.
- Solar iBoost and Eddi: For simpler setups, the Eddi power diverter from myenergi manages solar surplus diversion and can be time-programmed to complement a basic battery schedule.
Is Arbitrage Worth It Without Solar?
Yes. A standalone battery (no solar panels) used purely for Octopus Agile arbitrage can generate £700–£1,100 per year depending on battery size and the volatility of wholesale prices. Payback periods are typically 8–12 years for a standalone arbitrage battery — longer than with solar, but increasingly attractive. Many homeowners install solar and battery together and treat arbitrage as an additional income stream rather than the primary justification.
