How Much Electricity Does a Heat Pump Use

Heat pumps are becoming increasingly popular across the UK as homeowners and landlords look for more efficient and sustainable ways to heat their properties. Unlike a traditional boiler, which burns gas or oil, a heat pump extracts heat from the air or the ground and transfers it into the home using electricity. With rising energy costs, one of the most common questions is how much electricity a heat pump actually uses. Understanding this figure requires looking at the technology behind heat pumps, how efficiency is measured, and how usage varies depending on the home and lifestyle.

How Heat Pumps Work

A heat pump works by transferring heat from one place to another using a refrigeration cycle. In an air source heat pump, the system absorbs heat from the outside air, even when temperatures are low, and compresses it to a higher temperature before circulating it into the home through radiators, underfloor heating, or hot water systems. A ground source heat pump operates in a similar way but extracts heat from the ground instead of the air. Both types rely on electricity to power the compressor, the fan, and circulation pumps. This means electricity is the driving force that allows the system to capture and move heat rather than generating it through combustion.

Average Electricity Consumption

The electricity use of a heat pump depends on its size, the efficiency of the model, and the heating demand of the property. A typical air source heat pump for a standard UK home may use between 2 and 4 kilowatt hours of electricity for every hour it is operating at full load. This is higher than the electricity demand of a gas boiler but it is important to remember that a heat pump does not convert electricity directly into heat in the same way as an electric heater. Instead, it multiplies the effect, producing around three to four units of heat for every unit of electricity used. This is measured through the Coefficient of Performance, known as COP.

Coefficient of Performance and Seasonal Efficiency

The COP of a heat pump indicates how much heat is produced per unit of electricity. For example, if a heat pump has a COP of 3, it means that one kilowatt hour of electricity generates three kilowatt hours of heat. In real life, the efficiency varies depending on outside temperatures and system design. The Seasonal Coefficient of Performance, or SCOP, gives a more accurate picture by measuring efficiency across the whole year, including winter. A well-installed air source heat pump in the UK can achieve a SCOP of around 3, while ground source systems often achieve higher figures of 4 or more. This means that even though heat pumps use electricity, they can still be cheaper and more environmentally friendly to run compared with older gas or oil heating systems.

Daily and Annual Running Costs

To understand electricity use in practice, consider a three-bedroom house with an annual heat demand of 12,000 kilowatt hours. If this property uses an air source heat pump with a SCOP of 3, it would require about 4,000 kilowatt hours of electricity to meet its heating needs over the year. At an average electricity price of 28 pence per kilowatt hour, this would cost around £1,120. This can be compared with a gas boiler, which might use 12,000 kilowatt hours of gas at around 7 pence per unit, costing about £840. While gas currently appears cheaper per unit, the efficiency gains of heat pumps combined with the government’s push towards renewable electricity mean the gap is expected to narrow over time.

Factors That Affect Electricity Use

Several factors influence how much electricity a heat pump will use in practice. The insulation levels of the property are crucial. A well-insulated home with modern double glazing and draught proofing will retain heat far more effectively than an older property, meaning the heat pump will not need to work as hard. The size and output of the heat pump also matter. An undersized system will run constantly, while an oversized unit may cycle on and off inefficiently. The way the heating system is designed, including whether underfloor heating or larger radiators are installed, can also improve performance by allowing the heat pump to run at lower flow temperatures.

Comparing Heat Pumps to Other Heating Systems

When compared with direct electric heating, such as storage heaters or panel heaters, heat pumps are far more efficient. A direct electric heater has a COP of 1, meaning every kilowatt hour of electricity only produces one kilowatt hour of heat. This makes them three to four times less efficient than a heat pump. Compared with modern condensing gas boilers, heat pumps are often cheaper to run in well-insulated homes, especially as electricity becomes greener and more competitive in price. The environmental benefit is also greater, as heat pumps do not burn fossil fuels and can be powered by renewable electricity from the grid or from home solar panels.

Reducing Electricity Costs with Heat Pumps

Homeowners can reduce the electricity demand of a heat pump by improving insulation, investing in smart heating controls, and choosing a model with a high SCOP rating. Running the heat pump at lower but consistent temperatures is usually more efficient than switching it on and off for short bursts. If the home has solar panels, pairing them with a heat pump can significantly reduce running costs, as self-generated electricity can cover part of the demand. Regular servicing also helps maintain efficiency by ensuring the system is free from faults or blockages.

Conclusion

The electricity consumption of a heat pump varies depending on the property and the system, but a typical UK home might see usage of 2 to 4 kilowatt hours per hour of operation. This translates into several thousand kilowatt hours of electricity annually, but with efficiency ratings of three to four times that of direct electric heating, heat pumps provide a cost-effective and environmentally friendly solution. For homeowners and landlords, the key to maximising efficiency is good insulation, correct system design, and regular maintenance. With government backing and improvements in energy tariffs, heat pumps are set to become an increasingly important part of the UK’s transition to low carbon heating.