British Gas Heat Power explained: 10 hours of half-price electricity for heat pump owners
British Gas Heat Power gives heat pump households 10 hours of half-price electricity every day — seven overnight from midnight to 7am, and three more in the early afternoon from 1pm to 4pm. There's no peak rate. The standard rate applies for the remaining 14 hours. It's a simpler structure than Cosy Octopus and suits households that want meaningful cheap windows without managing a peak penalty.
How British Gas Heat Power works
British Gas Heat Power is a time-of-use tariff with two daily cheap windows. During these windows, electricity is charged at half the standard rate:
| Rate band | Times | Approx rate (Apr 2026) |
|---|---|---|
| Off-peak (half price) | 00:00–07:00 and 13:00–16:00 | ~12–13p/kWh |
| Standard | All other hours | ~24.7p/kWh |
That's 10 hours of cheap electricity per day — more than EDF FreePhase's 7-hour overnight window, and comparable in total hours to Cosy Octopus. Unlike Cosy, there is no peak rate: the most you'll ever pay outside the cheap windows is the standard cap rate.
The tariff is open to any household with a heat pump and a SMETS2 smart meter. You don't need to use Hive or any British Gas smart home product to access it, though Heat Power integrates with the Hive ecosystem if you already use it.
The 70-hour-per-week figure
British Gas describes Heat Power as providing 70 hours of half-price electricity per week (10 hours/day × 7 days). That framing is useful: it emphasises the total cheap-hour budget rather than just the overnight window, which is where Economy 7 and older tariffs concentrate all their value.
70 hours/week of cheap-rate access is substantial. For comparison:
- Economy 7: ~49 hours/week (7 hours/day overnight only)
- EDF FreePhase green window: ~49 hours/week (7 hours/day overnight only)
- Cosy Octopus: ~56 hours/week (8 hours/day across three windows)
- British Gas Heat Power: 70 hours/week (10 hours/day across two windows)
The midday window (13:00–16:00) is especially useful for heat pump owners, because outdoor air temperature is warmer during the early afternoon than overnight — meaning the heat pump runs more efficiently during those hours, giving you a COP bonus on top of the cheaper rate.
How it compares to other heat pump tariffs
| Tariff | Off-peak hours/day | Off-peak rate (Apr 2026) | Peak rate | Exit fee |
|---|---|---|---|---|
| British Gas Heat Power | 10 | ~12–13p/kWh | None | None |
| Cosy Octopus | 8 | ~14.5p/kWh | ~51.7p (16:00–19:00) | £25 (6-month fix) |
| E.ON Next Pumped | 21 (super + off-peak) | ~9–11p / ~16–21p | ~27p (16:00–19:00) | None |
| EDF FreePhase | 7 (green) + 13 (amber) | ~10–12p green / standard amber | Mild red rate | None |
| EDF Heat Pump Tracker | 6 | Standard −10p/kWh | Standard rate | None |
British Gas Heat Power sits in an interesting middle position. Its off-peak rate isn't the lowest on the market (E.ON Next Pumped's super off-peak at ~9–11p is cheaper), but it has the most off-peak hours without a peak penalty. That no-peak structure makes it genuinely low-risk: you never pay more than the standard cap rate, whatever time of day your heat pump runs.
Who benefits most from Heat Power
Households that can't reliably avoid a peak rate. Cosy Octopus's 16:00–19:00 peak at ~51.7p/kWh is the tariff's biggest risk. If your occupancy pattern means the heating runs during those hours — children home from school, cooking, evening heating — that peak exposure is significant. Heat Power removes it entirely.
Homes with a large hot water cylinder. The midnight-to-7am window is long enough to fully recover even a large cylinder (250+ litres) and run a space heating preheat before the morning. The 13:00–16:00 top-up window then adds resilience without requiring tight scheduling.
Heat pump households already with British Gas. Switching to Heat Power within British Gas avoids a full supplier switch, which means no switching delay, no new direct debit setup, and no smart meter re-enrolment lag. If the rates are competitive for your region and usage pattern, the friction of switching away from an incumbent supplier is worth factoring in.
Households with Hive smart controls. Heat Power integrates with Hive thermostats and hot water controllers, making it straightforward to align your heating schedules to the cheap windows if you already use the Hive ecosystem.
The catch: the off-peak rate isn't the lowest
British Gas Heat Power's cheap rate of ~12–13p/kWh is lower than the standard cap and lower than Cosy Octopus's off-peak (~14.5p), but it's not the cheapest off-peak rate available. E.ON Next Pumped's super off-peak window runs at ~9–11p/kWh, and EDF FreePhase's green window comes in at ~10–12p/kWh overnight.
Heat Power's value proposition is breadth rather than depth: more hours, no peak risk. Whether that combination outperforms a tariff with fewer but cheaper hours depends entirely on your usage pattern — specifically, how much of your consumption naturally falls in each window and whether you'd be able to avoid a peak rate on a different tariff.
There's no universal answer. A household with good scheduling capability and a Cosy-compatible heat pump controller will likely find Cosy Octopus or E.ON Next Pumped cheaper on an annual basis. A household with limited scheduling control will likely find Heat Power safer.
What you need to access Heat Power
- A SMETS2 smart meter (or SMETS1 enrolled with DCC) sending half-hourly data
- A heat pump installed at the property (British Gas verifies this)
- A British Gas electricity account, or willingness to switch to British Gas
British Gas installs smart meters free of charge if you don't have one yet. The switch itself typically takes five working days, with a further one to two weeks before the half-hourly tariff rates activate on your meter.
The short version
- British Gas Heat Power offers 10 hours of half-price electricity per day: 00:00–07:00 and 13:00–16:00.
- No peak rate — standard cap applies outside the cheap windows.
- The off-peak rate (~12–13p/kWh) is lower than Cosy Octopus but not the cheapest available.
- Best suited to households that want substantial cheap-hour coverage without managing a peak penalty.
- Integrates with Hive if you already use British Gas smart controls.
- No exit fee — you can switch at any time.
Compare British Gas Heat Power against every other heat pump tariff using your real usage data on Heat Pump Tariffs.