These key terms have been designed as a reference tool when you need more detail on a specific topic.
You can also download this as a pdf: Domestic RHI reference document
Terms for letter 'Z'
Most applicants will receive payments based on annual heat demand listed on their EPC or, in the case of solar thermal, from the estimated annual generation on their MCS Certificate. To see worked calculations of deemed payments, please see our Reference Document.
Some applicants may require metering for payment in order to be eligible, and will be paid directly on their meter readings. If you believe you may require metering for payment, and want to know more about how your payments will be calculated, you should see the Essential Guide to Metering.
The Government introduced heat demand limits on 20 September 2017. If you applied on or after the date the amendments to the regulations came into effect, annual heat demand limits will apply to you (unless you only have solar thermal). To learn more about how heat demand limits may affect your payments, please see Heat demand limit.
Biomass installations and heat pumps will be paid using the heat demand figures listed on the EPC, or the relevant heat demand limit, whichever is lower. Solar thermal systems are paid using the estimated annual generation figure on the MCS certificate. There is no heat demand limit for solar thermal. To see payment calculation examples for heat demand limits please see our Reference Document.
If you own a heat pump and are only metered for performance (subject to Parliamentary approval), you’ll continue to be paid based on your deemed annual heat demand.
The Government introduced heat demand limits on 20 September 2017. If you applied on or after this date, annual heat demand limits will apply to you (unless you only have solar thermal). To learn more about how heat demand limits may affect your payments, please read our Factsheet: Tariffs and Payments.
If you applied to the Domestic RHI on or after 20 September 2017, the total heat demand listed in your EPC will be capped at the heat demand limits. You can still apply if the heat demand listed on your Certificate is higher than the heat demand limit, but your RHI payments will be capped in line with the limit.
The heat demand limits are:
|Technology Type||Annual heat demand limit (kWh)|
|Air source heat pumps||20,000|
|Ground source heat pumps||30,000|
For worked examples of heat demand limit payment calculations, please see our Reference Document.
For the Domestic RHI a product is a particular type, make and model of heat pump, biomass boiler, biomass stove or solar thermal collector. All products must meet specific EN Standards for technology typesopen key term pop-up (as well as meeting the other eligibility requirements for the scheme).
The Product eligibility list (PEL) identifies individual products that meet the technology requirements for the Domestic RHI. It allows you to check whether a specific product is eligible for the scheme before purchasing a heating system. The list only indicates that the product is eligible, and is not a guarantee of overall eligibility for the Domestic RHI.
The PEL lists information provided on products by Certification Bodies and manufacturers and presents it in a spreadsheet which you can use to check whether a particular product is eligible, or to find out particular information about a product.
Important note: if your product is not listed on the PEL, it does not mean that it is automatically ineligible. It could be that we haven’t yet received all of the required information from the product manufacturer. All products must meet the relevant EN Standards in order to be eligible. If your product is not listed on the PEL, but you think it may be eligible, you should speak to your installer to discuss your next steps.