Domestic RHI

Domestic RHI

What is domestic RHI?

Domestic Renewable Heat Incentive (RHI) was launched on April 9, 2014, and is phase 2 of the government's scheme to reduce carbon emissions. Like the commercial scheme, it has been designed to drive forward uptake of renewable heat technologies in homes across the UK. This will reduce carbon, helping meet renewables targets and save money on fuel bills. 

Who is eligible for the domestic RHI?

The scheme is open to anyone who can meet the joining requirements. It’s for households both off and on the gas grid. Essentially, tt is open to home owners living in the same property, private and registered social landlords and self-builders. Anyone who has installed an eligible renewable heat technology system since July 15, 2009 and meets the scheme eligibility criteria should be able to join.

What are the recent changes to the RHI?

In November 2015, the UK government renewed its commitment to the transition to a low carbon economy, by confirming a continued budget for the RHI out to 2020/21. Following a series of consultations from March-April 2016, the government finalised a package of reforms to the RHI schemes in December 2016. The General Election announcement delayed the plans to implement the proposed changes to the scheme.

Subject to Parliamentary approval, the changes to the scheme Regulations that were announced in the consultation response are planned to be introduced in two stages. It has now been decided that the government's raft of changes to its world's first Renewable Heat Incentive will be implemented on September 20, 2017, whilst declaring intentions for more of the proposed changes to follow later in 2017/18. These changes include: tariff uplifts for air source heat pumps (ASHP), ground source heat pumps (GSHP), and biomass plants; and the introduction of annual heat demand limits for ASHPs, GSHPs, and biomass plants. The changes being implemented includes new non-domestic biomass tariffs, new domestic tariffs, domestic heat demand limits, and provisions to extend these to anyone accredited since December 14, 2016. The amendments will also extend the scheme’s budget management mechanisms until July 2018. 

The Department for Business, Energy and Industrial Strategy (BEIS) has subsequently announced that no tariff degressions will be applied to either the domestic or non-domestic scheme on October 1, 2017, with the next potential degressions being applied January 1, 2018.

Below is a table of the domestic RHI tariff as of September 20, 2017, along with the historical RHI rates:

Applications submitted Biomass boilers and stoves (p/kWh)
01/01/2019-31/03/2019* 6.74p
01/04/2019 - 30/06/2019 6.88p
01/07/2019-30/09/2019* 6.88p
01/10/2019 - 31/12/2019 If any new tariff changes are to be made due to degression, the announcement by BEIS would be made by 1 August 2019.

* these tariffs were adjusted in line with CPI

How do I calculate my payback?

The domestic tariff has been set at a level that reflects the expected cost of renewable heat generation over seven years. Payments will be made based on estimated (deemed) heat demand of the property.

Following the changes that have been implemented to reform the RHI scheme, domestic RHI payments will be calculated based on unit payments of 6.88p per kilowatt hour (kWh) as of September 20, 2017. This is still deemed and based on customers' Energy Performance Certificate (EPC), but with a maximum of 25,000kWh per annum. Properties with heat demands above this level will be paid the same as if the property’s heat demand were equal to the limit.

As a rule of thumb, to calculate the size of biomass boiler your property will need, you divide the EPC value by 1,314. To calculate your payments, you multiply your EPC by 6.88p per kWh. If you haven’t already got your EPC, we will be more than happy to give you an idea of the cost of installing a biomass boiler and the RHI payments you can expect. Just contact us.

The figures are all index linked to inflation. Alternatively, take a look at Rainbow Heat and Power’s domestic RHI calculator to see what your project could deliver to you in financial and environmental terms.

Additionally, the Department of Energy and Climate Change will offer an extra, set payment of £200 per year where metering and monitoring support packages are required for biomass boilers.

What is an EPC?

An EPC or Energy Performance Certificate essentially defines your property's heat load. To start off, the property the biomass boiler will be serving will need a domestic EPC. The EPC is needed by Ofgem to prove that your property is assessed to be a domestic dwelling. Without one you are unable to apply to join the scheme.

To gain an EPC, applicants need to have completed a Green Deal Assessment. Applicants must ensure they have met minimum loft (250mm) and cavity insulation or solid wall insulation requirements where appropriate. Once the assessment is complete an EPC is issued as proof of domestic dwelling status, completion of energy saving measures and it will define the heat demand for the property.

RHI Domestic Calculator

Eligible biomass boiler systems

RHI domestic supports a range of renewable heating technologies but at Rainbow Heat and Power we only deal with biomass boilers. We have a wide range of boilers suitable for the domestic scheme. Since September 2013 emission levels must be below 30g g/GJ particulate matters and 150g/Gj Nitrogen Oxide.

In the UK all installations and installers must be Microgeneration Certification Scheme (MCS) certified (or certified by an equivalent scheme). MCS certified installers are currently required to be members of the Renewable Energy Consumer Code, which is backed by the Trading Standards Institute.

Effecta biomass boilers - suitable for the domestic RHI

Rainbow Heat and Power supplies a range of biomass boilers suitable for the domestic RHI scheme. Please see our full range of Effecta biomass boilers for details.

Below is a table outlining the specific emissions and linking to emissions certificates for all of the Effecta biomass boilers below 45kW.

Effecta Lambda

Maximum emissions 30 g/GJ 150 g/GJ
Lambda Log Boiler 25 9.7 g/GJ 138 g/GJ
Lambda Log Boiler 35 13 g/GJ 91 g/GJ


Effecta Komplett III PM NOx
Maximum emissions 30 g/GJ 150 g/GJ
Komplett III Range 7 g/GJ 99 g/GJ