Domestic Renewable Heat Incentive duration seven years from acceptance
To qualify for the domestic renewable heat incentive scheme it has to be a private dwelling with an energy performance certificate (EPC) for the building. The EPC shows the amount of heat required per year for heating and hot water and that it is also shows it is suitable dwelling. The amount of renewable heat produced is calculated by taking the total annual heat requirement and deducting the electricity it takes to generate it. No heat meter is required for a simple system but if the heat pump is not the only source of heat for the building for instance when a gas boiler is used to boost the heating during really cold periods a heat meter has to be fitted to show the amount of heat provided by the heat pump. The payment for 2016 is 7.51p per kWh for air source heat pumps and 19.33p per kWh for ground source heat pumps.
Small print (you can skip this bit if you like)
The ratio of renewable heat to electrical input is determined by the seasonal performance factor (SPF). This is shown and can be seen in the Heat Emitter Guide.
The seasonal performance factor is worked out by taking the efficiency of the heat pump at the temperatures it will be producing over the course of a year. The highest figures for this shown in the guide are 4.3 for a ground source heat pump and 3.6 for an air source heat pump. This means if you need 20,000 kilowatt hours for your heating you will need 4,651 units (kWh) of electricity to run a ground source heat pump and 5,555 units of electricity to run an air sour heat pump. The renewable heat incentive payment would be calculated on the rest so for a ground source heat pump it would be 20,000 kWh – 4,651 kWh = 15,349 kWh x 19.33p = £2966.96 per year and for an air source heat pump it would be 20,000kWh – 5,555 kWh = 14,445 kWh x 7.51 = £10854.19 per year. These figures are based on a heating water flow temperature of 35ᵒC to get enough heat you will need special or larger radiators or under floor heat or perhaps a combination of both. As the renewable heat incentive payments are just for heat produced from renewable energy source (the sun heating the ground or the air from which the heat pump extracts the heat) some domestic installations also need a heat meter for instance when more than one type of heating is used such as a gas boiler. More information on the domestic renewable heat incentive can be found here on the Ofgem RHI portal
Non Domestic Renewable Heat Incentive duration twenty years from acceptance
The non domestic renewable heat incentive scheme covers installations for business premises, social housing, district and communal heating systems. The heat produced by the heat pump is measured by a heat meter which is installed in the heating water circuit. This meter calculates the amount of heat produced by comparing the difference in the temperature of the heating water entering and leaving the heat pump, multiplying this by the volume of water going through the heat pump and then multiplying the result by the amount of energy it takes to heat that volume of water by that amount. A heating system doesn’t run continuously, it goes on and off in line with the demand for heat. We take the calculated heat load for a year and divide it by the rated capacity of the system to get the number of hours it would have to run at full blast. This is called the Full Load Equivalent (FLEQ) and an average space heating system would be designed to have an FLEQ of 1800 hours for space heating.
The renewable heat incentive payment for heat is greater than the cost of the electricity required to generate it, to make sure participants don’t just waste heat the payments are tiered with the equivalent of the first 1314 hours of the system running at full capacity paid at 8.95p per kWh and all subsequent hours paid at 2.67p per kWh the aim being to generated average payments of 7.2p per kWh for normal usage and less than cost for wasteful usage.
To demonstrate this let’s take a 20kW system designed to provide 36,000 kWh of heat per year. The FLEQ is 36,000 (kWh) divided by 20 (kW) = 1800 hrs. The RHI payment calculation would be the first 1,314 hrs x 20 kW x 8.95p = £2352.06 plus the remaining 486 hrs x 20 kW x 2.67p = £259.52 totalling £2611.58 and this total amount divided by 36,000kWh is 7.2p per kilowatt. It is extremely important to make sure the system is designed correctly to benefit fully from RHI payments.
More information on the non domestic renewable heat incentive can be found at the Ofgem non domestic RHI portal
Or if you would like to have a chat about the renewable heat incentive in connection with a heat pump you are considering please feel free call us on 01344 380044