Cosy Octopus: the heat pump tariff
Three cheap blocks a day, one peak · Electricity
Cosy Octopus is built around a heat pump's duty cycle: three cheap blocks spread through the day so the house can be pre-heated, and a peak rate in the evening to keep you off the grid when it is busiest.
Cosy Octopus in London right now
- Unit rate now
- 12.44p/kWh
- Standing charge
- 40.40p/day
- Cheapest today
- 12.44p/kWh
- Dearest today
- 38.04p/kWh
- Tariff code
- E-1R-COSY-22-12-08-C
Prices include VAT and are for London (region C). Change region · Full half-hourly view
The shape of the day
Cosy has three cheap periods — an overnight block, one in the late morning and one in the afternoon — plus a peak period covering the early evening, and a standard rate for everything left over. The idea is that a heat pump and a hot-water tank run hard in the cheap blocks, and the building's own thermal mass carries the house through the peak.
Because the blocks are at fixed times, Cosy rewards a heating schedule rather than constant attention. That is the practical difference from Agile, where the cheap half hours move every day.
Who it actually suits
Cosy is a good tariff for a heat pump in a reasonably insulated house, and a poor one for a household that cooks and washes in the evening peak. If you have storage heaters, an electric hot-water cylinder or a home battery, it is worth pricing; if your heating is gas, it almost certainly is not.
Price it against your own readings on the compare page — a tariff with time bands lives or dies on how much of your usage falls in each one.
Common questions
What are the Cosy Octopus cheap hours?
Cosy has three cheap blocks a day — overnight, late morning and afternoon — with a peak rate in the early evening. The live rates on this page show the exact bands for your region.
Do I need a heat pump for Cosy Octopus?
No, but the tariff is priced for one. Cosy pays off when a large, schedulable electric heating load can be moved into the cheap blocks.
Which tariff is cheapest for you? Headline rates cannot answer that. Connect your Octopus account and halfhourly.uk prices your last 28 days of real half-hourly readings against every tariff's real rates, standing charge included.