Octopus Intelligent Go vs Cosy vs Agile — Tariff Guide 2026

Octopus Intelligent Go gives you 6 hours of cheap overnight electricity at around 7p/kWh (mid-2026 pricing), against a standard peak rate of around 27p/kWh. The clever part: Octopus controls when in the night your car actually charges, optimising against grid pricing.

You need a smart EV charger Octopus can talk to (most major brands: Ohme, Wallbox, Hypervolt, Andersen, Tesla via direct integration). The charger sends scheduling data; Octopus responds with the cheap-rate windows.

Cheap rate applies to all your electricity during the smart window, not just the EV. So if you've set your dishwasher and washing machine on a timer, they benefit too.

Best for: EV-only households, no heat pump. Typical saving against a flat 27p tariff for a 30-mile daily commute: £900-1,100 per year.

Cosy targets heat pump owners and gives you three cheap windows per day: early morning (around 4-7am), midday (around 1-4pm), and afternoon (around 4-7pm). Rates around 12-15p/kWh in the cheap windows, around 30-35p in peak (5-8pm), and around 25p the rest of the time.

The structure suits heat pump operation: pre-warm the property in early-morning cheap window, top up midday with the second cheap window, and avoid the 5-8pm peak.

Smart thermostats (Hive, Nest, Tado, Drayton) can be scheduled around the Cosy windows. Many heat pump controls now have a 'Cosy mode' preset.

Best for: ASHP-heated homes, particularly under-floor heating which holds heat well. Saves typically £400-700 per year vs flat-rate tariffs.

Agile is half-hourly variable pricing tied to wholesale rates. Prices announced day-ahead. Negative pricing (you get paid to use electricity) happens 30-50 days a year, typically Sunday lunchtimes when solar peaks and demand is low.

You need a home battery that can charge at variable times and an automation system (Home Assistant, Octopus Mini, or some inverters natively) that times battery charging against the day-ahead price feed.

Without automation, Agile is risky — you might be charging at peak prices if you don't watch the half-hour windows. With automation, savings are excellent.

Best for: solar + battery households with smart energy management. Typical saving £600-1,200 per year for a 13.5 kWh battery system actively managed.

If you have solar PV exported back to the grid, Octopus Outgoing Agile pays variable half-hourly export rates. Cap is 35p/kWh in mid-2026, average around 14-18p.

Stack with import Agile for full half-hourly trading — charge battery on cheap import, export at peak. Real-world savings for a 7 kW PV + 13.5 kWh battery system: £900-1,400/year.

Outgoing Fixed pays a flat rate (15p in mid-2026). Lower ceiling, lower hassle. Good for export-and-forget setups.

If you're not on Octopus, the major suppliers all now offer SEG export tariffs — but Octopus rates are typically 1-3p/kWh higher than the next best competitor.

EV only, no heat pump, no solar: Intelligent Go. Easy win.

Heat pump, no EV: Cosy. The three cheap windows align with heat pump operation patterns.

EV + heat pump, no battery: Cosy edges Intelligent Go for combined cost, but Intelligent Go wins if your EV is the dominant load (10,000+ miles/year).

Solar + battery + EV + heat pump (the full stack): Agile import + Outgoing Agile export, with automation. Highest savings ceiling but requires the right kit.

Switching tariffs is fast on Octopus — under 7 days from app request. Try one for 3 months, look at the bill, switch if it's not working. Most households end up on whichever fits their largest load.