Octopus Energy added a third off-peak period to its Cosy Octopus import tariff in July 2024, extending the cheap-rate window to 10pm to 12am1. The change means the tariff now offers three daily off-peak periods, called Cosy Hours, running from 4am to 7am, 1pm to 4pm and 10pm to 12am, with a peak rate from 4pm to 7pm1.
Cosy Octopus is an import tariff with off-peak and peak periods that is available to any household with an air or ground source heat pump and a smart meter1. The meter can be an SMETS2 model or an SMETS1 meter that is Secure-branded1. Eligibility does not depend on who supplied or installed the heat pump, though Octopus may check certification by the Microgeneration Certification Scheme1. Households that are not already Octopus customers are moved onto one of its standard tariffs first, a process the supplier says should take no more than three weeks1.
The tariff's rates are updated every three months and track Ofgem's price cap, with the day rate set slightly higher than the cap1. Off-peak electricity is 51 per cent cheaper than the day rate and peak electricity is 50 per cent more expensive1. For April to June 2026, the published figures are:
| Period | Rate |
|---|---|
| Off-peak | 14.53p per kWh |
| Day rate | 33.28p per kWh |
| Peak | 51.68p per kWh |
Those rates are national figures; the same source lists Birmingham at 49.83p peak, 13.93p off-peak and 32.05p day rate1. For comparison, many UK households pay a flat 24.67p per kWh under the price cap for the same three-month period1.
"Thankfully, it's even easier to save with Cosy Octopus now, ever since the company introduced a third off-peak period, the 10pm-12am window, in July 2024."
The source estimates a typical three-bedroom household with a heat pump uses 6,600kWh a year, costing £1,837 on the April 2026 price cap, and puts the saving from Cosy Octopus at around £35 a year, assuming 9 per cent of usage is shifted into each of the eight daily off-peak hours and the peak period is avoided entirely1. It notes results will vary. Cosy Octopus is an import tariff only, so solar owners would need a separate export tariff; the source states the tariff offers a flat export rate of 12p per kWh and values it at £153 a year for a household with a 4.9kWp system, a 5.2kWh battery, annual consumption of 3,400kWh and typical UK solar irradiance1. There are no exit fees or penalties for leaving1.
Why it matters for households
A heat pump typically raises a home's electricity use, and the source puts that extra demand at around 3,200kWh a year on top of the 3,400kWh an average household uses1. Running a heat pump on a flat-rate tariff therefore exposes a household to the full unit price for every kilowatt-hour. A tariff with defined cheap windows changes the arithmetic: the same heat pump, run mostly inside those windows, draws power at roughly half the day rate, while any use in the 4pm to 7pm peak costs half as much again1. The practical effect depends on how much load a household can move, which for heating means running the heat pump and hot water outside the peak and accepting some variation in when rooms are warmed. The third window added in July 2024 extends the cheap hours into the late evening, when many homes are occupied and appliances are in use. For a home with a battery, the off-peak windows also allow grid charging for later use, which is where much of the value in the source's solar and battery estimate comes from1. Households without a smart meter cannot access the tariff; the source says a smart meter can be installed free by contacting an energy supplier1.
What happens next
Cosy Octopus rates are updated every three months in line with Ofgem's price cap announcements1. No further changes to the tariff's structure have been reported.
Sources1 cited
- Cosy Octopus: explained 2026, sunsave.energy