Which UK time-of-use tariff earns most on a home or commercial battery in 2026? Octopus Flux, Cosy Octopus, Intelligent Octopus, Tesla Energy Plan, Ovo Charge Anytime, British Gas EV Tariff — compared on real customer data, not marketing.
Most modern batteries (Sigenergy SigenStor, Tesla Powerwall 3, Aelio, Solax T-Bat) qualify for Virtual Power Plant programmes that pay you for grid-balancing services. Real 2026 ranges from KMM customers:
Octopus VPP (via Power Pack): £60-£140/yr on a 10 kWh battery
Tesla VPP (Energy Plan customers): £80-£180/yr on a Powerwall 2/3
Ovo VPP (CrowdFlex): £40-£90/yr
Sigenergy VPP (via Octopus or Centrica): £150-£280/yr — higher because of multi-stack capacity
How to choose your battery tariff
Step 1 — Audit your consumption. Pull 12 months of HH data. Identify your peak-time consumption (16:00-19:00 typically) — that is what battery arbitrage protects against.
Step 2 — Match the cheap window. If you have a heat pump, Cosy gives you 3 cheap windows daily. If you have an EV but no heat pump, Intelligent Octopus or Ovo Charge Anytime is cheaper still. If you have neither, Flux is the highest-earning.
Step 3 — Check export rate. If you have solar above 4 kWp, the export rate matters more than the import rate. Flux's variable export rate (13-26p depending on time) beats most fixed-export tariffs over a year.
Step 4 — Check exit fees. Many fixed tariffs charge £75-£150 per fuel to leave early. Worth it if savings justify, but check first.
Get a battery tariff recommendation with your KMM install
Every battery install comes with a 12-month HH data audit and tariff recommendation — bound into your quote, not bolted on as an upsell.
For most installs with solar PV, Octopus Flux earns the most — typically £350-£450/yr arbitrage on a 13.5 kWh battery. For heat-pump-led homes, Cosy Octopus often beats Flux. For EV-led households, Intelligent Octopus or Ovo Charge Anytime are typically cheaper for import but lower-earning on export.
What is a Virtual Power Plant (VPP) and how much does it pay?
A VPP aggregates many home or commercial batteries into a virtual grid asset that responds to grid balancing signals from the National Grid ESO. Octopus, Tesla, Ovo and Centrica all operate VPPs in the UK. Earnings range from £40-£280/yr depending on battery size, location and programme.
Can I switch tariffs after installing a battery?
Yes — most batteries are tariff-agnostic. The exception is the Tesla Powerwall on a Tesla Energy Plan, which requires you to stay on the Energy Plan to maintain the flat 8.5p rate. Other batteries (Sigenergy, Aelio, Solax, Fox) can switch tariffs freely.
Do I need a smart meter for a battery tariff?
Yes — all time-of-use tariffs require a SMETS2 smart meter recording half-hourly. If you do not have one, your supplier will fit one free before you can switch to a time-of-use tariff.
How long does it take to switch tariffs?
Typically 17-21 days from request to switch date. The 14-day cooling-off period is standard. Some suppliers (Octopus, Ovo) can fast-track in 5-7 days if you remain with them on a new tariff.
