Heat Pump Tariffs, in General

A heat pump tariff is an electricity tariff whose price structure suits a home that uses a lot of electricity for heating, and its effect on running costs can be as large as the difference between two heat pump models. Standard tariffs charge a single rate all day, time-of-use tariffs charge less overnight and more at peak evening times, and some suppliers offer heat-pump-specific tariffs with a lower rate for heat pump electricity, sometimes on a separate meter or circuit, sometimes on the whole household supply. The right tariff depends on when the heat pump runs, when other household loads run and how much load can be shifted to cheap hours without losing comfort.

Load shifting is the key idea. A heat pump that pre-warms a well-insulated home or heats a cylinder during cheap overnight hours, then coasts through expensive peak hours, can cost considerably less to run than the same heat pump running flat out at peak price, even though both use the same total electricity. That shifting must be balanced against comfort and cylinder hygiene, and it needs controls that can follow a tariff schedule.

Tariff comparison must include standing charges, not just unit rates, because a heat pump tariff with a low unit rate but a high standing charge can cost more overall for a smaller household, while a tariff with a separate heat pump meter may add a second standing charge. Export, where solar panels exist, interacts too: a household that exports solar electricity at a low rate while importing heat pump electricity at a high peak rate needs a combined view, not separate tariff decisions for solar and heating.

Metering matters for the same reason. Smart meters that record half-hourly use enable time-of-use tariffs, while older meters may not, and a heat pump tariff that requires a specific meter type, a specific control or a supplier-approved installer should be checked before the heat pump is ordered, not after, since changing meter or control afterwards can be costly.

Before choosing a tariff, list the heat pump running pattern across a typical winter week, the other large loads and their timing, and whether the household can accept pre-warming or overnight cylinder heating. Compare total annual cost, including standing charges, on the same usage pattern, across at least two tariff types, and check whether the tariff rate is fixed or variable, for how long, and what happens on renewal.

Also ask whether the heat pump controls can follow the tariff, whether a battery or thermal store, if present, changes the case, and what happens during a tariff change or a supplier switch. A tariff that depends on a control feature nobody has set up will not deliver its promised saving.

In the EU, heat pump tariffs and electricity market rules are national, with member states differing on time-of-use availability, on dedicated heat pump tariffs, on taxes and levies on electricity versus gas, and on whether heat pump electricity is metered separately. Those tax and levy differences can make a heat pump cheap to run in one country and expensive in another, even with the same unit and the same home.

In the UK, Ofgem regulates supplier tariffs and consumer protections, time-of-use tariffs depend on smart metering, and several suppliers offer heat-pump-specific products whose terms change frequently. A tariff comparison should therefore be dated and repeated at renewal, rather than treated as a permanent feature of the heat pump installation.

A frequent mistake is comparing heat pump running costs using a single, average electricity price, when the actual cost depends on the tariff structure and the running pattern, so two homes with identical heat pumps can have very different bills. Another is choosing a cheap overnight tariff and then running the heat pump mainly at peak times because controls were never set to shift load, so the tariff benefit is never captured.

A third mistake is ignoring standing charges and export interaction, so a tariff that looks cheap per unit costs more overall, or a solar household exports cheaply while importing expensively. Total annual cost, on a realistic pattern, is the only fair comparison.

Keep the tariff terms, the comparison calculations with their usage assumptions, the meter type note, the control settings for tariff following and any supplier correspondence about rate changes. Those papers let a later tariff switch be judged from evidence, not from a single bill.

Ask a qualified installer or supplier: what running pattern did you assume, what total annual cost follows on this tariff versus a standard tariff, can these controls follow a time-of-use schedule, and what changes if the tariff rate moves. Tariff-specific, total-cost answers show a realistic running cost case.