How Much Are RHI Payments for Heat Pumps?

Renewable Heat Incentive payments for both ground source and air source heat pumps are calculated using a simple equation. Well, simple if you know what you’re doing.

The Renewable Heat Incentive


Heat Pumps

Based on similar technology to air conditioners and freezers, heat pumps use the heat found in air, water or the ground and compress it using electricity. This compression causes the extracted warmth to heat up further and then used for either water or space heating.

Step One: Annual Heat Demand




Since 2017, the annual heat demand for RHI heat pump applications has been capped at 30,000 kWh. If your heat demand is above that, your payments will still be calculated on the basis of 30,000 kWh.

Step Two: RHI Tariff Rate



The rates we’re using here are the Renewable Heat Incentive tariff rates, accurate of April 2019.

Step Three: Adjust for the Seasonal Coefficient of Performance (SCoP)

Heat pumps use a certain amount of energy to run, which means that your heat demand needs to be adjusted to take into account the efficiency of the heat pump. This efficiency is called the Seasonal Coefficient of Performance(SCoP) and it’s all to do with how much heat can be generated per unit of electricity; normally it’s between 2.5 and 4. You SCOP score needs to be determined by an MCS installer as part of the installation process.

Divide your annual demand by the Seasonal Coefficient of Performance(SCoP). This will give you a number representing the annual energy consumption of the heat pump.

25,000 / 3.5 = 7,142kWh/yr

Take this annual energy consumption away from your annual heat demand to calculate the renewable proportion of your heat demand.

25,000 – 7,142 = 17,857kWh/yr

It’s this figure that you can claim the RHI on.

Step Four: Calculating Quartlery, Annual, and Total Repayments


First we have to divide the tariff rate by 100 to get it into a standard currency format, as opposed to pence. So the ground source rate of 20.89p tariff rate becomes £0.2089, and the air source heat pump rate of 10.71p becomes £0.1071.

Annual Payments:


Quarterly Payments:

Divide your annual payments by 4.

Total RHI Payments:

Multiply your annual payments by 7.


We’ve put some examples below of how different heat demands create.

An Air Source Heat Pump with a SCoP of 3.2:

BuildingHeat Demand On EPCFinal Applicable Heat DemandQuarterly PaymentAnnual PaymentTotal RHI Payback
Small house, good insulation6,0004,065£108.83£435.31£3,047.17
Medium house, average insulation12,0008,129£217.65£870.62£6,094.34
Large house, poor insulation20,00013,548£362.76£1,451.03£10,157.23

A Ground Source Heat Pump with a SCoP of 4:

BuildingHeat Demand On EPCFinal Applicable Heat DemandQuarterly PaymentAnnual PaymentTotal RHI Payback
Small house, good insulation6,0004,500£235.01£940.05£6,580.35
Medium house, average insulation12,0009,000£470.03£1,880.10£13,160.70
Large house, poor insulation30,00022,500£1,175.06£4,700.25£32,901.75

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