If you’ve installed solar, a home battery, an EV charger or a heat pump, your old standard variable tariff is leaving money on the table. Time-of-use (TOU) tariffs charge dramatically less for electricity at off-peak hours — typically 7-9p/kWh overnight versus 25-28p/kWh during evening peak. Switching can save £400-£1,200 a year on the right setup.
Here’s the 2026 comparison.
The contenders
Major UK smart tariffs in May 2026 with meaningful off-peak windows:
| Tariff | Off-peak rate | Off-peak window | Peak rate | Best for |
|---|---|---|---|---|
| Octopus Go | 8.5p/kWh | 5 hrs (00:30-05:30) | ~28p/kWh | Standalone battery, predictable overnight users |
| Intelligent Octopus Go | 7p/kWh | Smart-scheduled (6+ hrs) | ~28p/kWh | EV drivers, EV + battery combo |
| Octopus Cosy | 8p/kWh | 3 windows (06-08, 13-16, 22-00) | ~32p/kWh peak (16-19) | Heat pump owners |
| Octopus Agile | Variable (-30p to +50p) | Half-hourly | Half-hourly | Engaged users, large battery |
| EDF GoElectric Overnight | 9p/kWh | 5 hrs (00:00-05:00) | ~27p/kWh | EDF customers, simple setup |
| British Gas Electric Driver | 9.5p/kWh | 5 hrs (00:00-05:00) | ~27p/kWh | British Gas import customers |
| OVO Charge Anytime | 7p/kWh | Smart-scheduled | ~28p/kWh | OVO customers with EV |
| Octopus Flux | ~3-12p/kWh | Multi-window with export bonus | Variable | Solar + battery combo specifically |
| Tesla Energy Plan | Variable, low | Smart-scheduled | Variable | Tesla Powerwall owners only |
Picking by setup
The right tariff depends almost entirely on what kit you have.
If you have a battery only (no EV, no solar)
Best: Octopus Go. Simple flat 8.5p/kWh window for 5 hours overnight. Battery charges fully during the window; discharges during the day. Annual saving over a standard variable tariff for a typical 3-bed semi with a 10kWh battery: £450-£700.
Runner-up: EDF GoElectric. Similar structure, slightly higher rate (9p), but useful if you want to stay with EDF for import without switching.
Skip: Octopus Agile — variable rates need a level of engagement that doesn’t justify itself for battery-only without an EV. Octopus Flux — needs solar to make sense.
If you have an EV only (no battery, no solar)
Best: Intelligent Octopus Go. 7p/kWh, smart-scheduled around your EV’s target charge time. You set “70% by 7am”; Octopus finds the cheapest 7-8 hours overnight to deliver that. Annual saving versus standard variable for typical 8,000-mile-a-year EV driver: £600-£900.
Runner-up: OVO Charge Anytime. Same 7p/kWh, similar smart scheduling. Useful if you’re an OVO customer.
Skip: Octopus Go — the standard 5-hour window is wasted on EV-only setups because Intelligent’s smart scheduling consistently delivers more cheap hours.
If you have an EV + battery (no solar)
Best: Intelligent Octopus Go. Same as above. Battery charges fully during the smart-scheduled overnight window, EV charges from same window. Both discharge during the day. Annual saving £900-£1,400.
Runner-up: Octopus Cosy — if you also have a heat pump, the multi-window structure with mid-afternoon off-peak helps cover heat pump runtime.
If you have solar + battery (no EV)
Best: Octopus Flux. Three-window tariff specifically designed for solar + battery owners. Cheap off-peak charging window at 3-4am, high export tariff between 4-7pm (battery discharges into the export market at premium rates). Annual benefit vs standard SEG: £150-£300 on top of normal battery savings.
Runner-up: Octopus Outgoing Fixed (15p/kWh export) + Octopus Go (import). Simpler setup, marginally less optimal economics. Pure SEG export plus cheap battery import covers most of what Flux delivers.
Skip: Agile — variable rates create unpredictability that’s incompatible with the SEG-paid export from solar.
If you have an EV + battery + solar (the full package)
Best: Intelligent Octopus Go (import) + Octopus Outgoing Fixed (export). Cleanest setup. Smart-scheduled overnight charging for both EV and battery. 15p/kWh SEG export rate for any surplus solar that the battery can’t capture. Annual total benefit vs standard tariff for typical full-package setup: £1,400-£1,900.
Alternative: Octopus Flux. Marginally higher peak export income but requires more configuration of the battery management system. We typically recommend the simpler Intelligent + Outgoing setup unless customers specifically want to optimise further.
If you have a heat pump (with or without other kit)
Best: Octopus Cosy. Three off-peak windows (early morning, mid-afternoon, late evening) align with heat pump operating patterns. Peak rate is high (~32p/kWh between 16-19) but the windows around it are cheap (8p/kWh). Lets the heat pump pre-heat during off-peak and coast through peak.
Runner-up: Intelligent Octopus Go — if you also have an EV. The single 7p window is less heat-pump-optimal than Cosy but the EV cost saving offsets.
If you have a Tesla Powerwall
Best: Tesla Energy Plan. Bundled import-and-export tariff exclusive to Powerwall owners. Variable import rates (lower than Octopus Go on most nights) plus up to 24p/kWh SEG export — the highest in the UK. Tesla’s algorithm handles all the scheduling. Annual benefit vs standard import + standard SEG: £400-£700 above what a typical Octopus setup delivers.
When Agile makes sense
Octopus Agile pays a variable rate that tracks day-ahead wholesale electricity prices. On windy nights and sunny summer afternoons, the rate can go below 0p/kWh — Octopus literally pays you to use electricity. Rates can also spike to 30p+ during evening peak.
Agile rewards engagement: if you actively shift large loads (battery charging, EV charging, washing machine, dishwasher, heat pump cycles) into cheap windows, you save 20-30% vs Octopus Go. If you don’t engage and just leave the system on auto, you typically save less than Octopus Go.
Worth it for:
- People with a battery large enough to ride out peak periods entirely
- Engaged users who genuinely enjoy watching rates and shifting consumption
- Anyone with a 13.5kWh+ battery and solar (combination dramatically improves Agile economics)
Skip if:
- You don’t want to think about electricity pricing
- Your battery is 5kWh or smaller (not enough buffer to ride peak periods)
- Your consumption pattern is fixed (small kids, shift work, etc.)
Switching mechanics
You can have an import tariff with one supplier and an export tariff with another. Most customers benefit from:
- Switching import to the relevant smart tariff (typically Octopus or similar)
- Switching export to the highest-paying SEG tariff (typically Octopus Outgoing Fixed at 15p/kWh, or Tesla Energy Plan at 24p/kWh for Powerwall owners)
Smart meters that report half-hourly readings are essential. SMETS1 meters often don’t — if you have one, ask your import supplier for a smart meter upgrade (free, takes 1-2 hours).
We help every AMP customer through the tariff switch as part of solar, battery or EV charger install handover. Switching takes 2-3 weeks (Octopus is fastest, typically 14 days).
What changes for 2026-2028
Three things to watch:
TOU tariff multiplication. Every major supplier is launching smart tariff variants. By 2027 expect 15-20 mainstream UK TOU tariffs, with more specialisation by use case (EV-only, heat-pump-only, solar+battery, etc.).
Half-hourly settlement. Ofgem’s market-wide half-hourly settlement (MHHS) launched in stages through 2025-2026. The mechanics behind smart tariffs are becoming more granular — expect rate windows to shrink (15-min granularity in some tariffs) as 2027 approaches.
V2G market commercialisation. Octopus’s V2G trial is expected to commercialise into a standard tariff option by 2027. EV drivers with V2X-capable cars (Hyundai/Kia E-GMP, VW MEB, etc.) will have an additional revenue stream from grid-services participation.
The right tariff today won’t be the right tariff in three years. Plan to review your tariff annually — we help our customers do this as part of standard aftercare.
Book a free survey → to get a system designed for the tariff that actually fits your usage pattern, not a generic install with whatever tariff comes out of the box.
Related: Best home battery UK 2026 · V2H and V2G in 2026 · Smart Export Guarantee explained 2026