To be eligible, both the equipment and the installer for domestic and for small (less than 45kW) non-domestic solar thermal systems will have to be accredited under the Microgeneration Certification Scheme (MCS). You can use the MCS website to find accredited installers.
The Ofgem website has lots more information on the RHI scheme and how to apply.
Support for domestic solar water heating installations
The tariff for solar water heating is currently set at 19.74p per kWh, and will be paid for 7 years. The kWh is the standard unit of heat payment, used in electricity and gas bills.
A solar water heating system generating between 1000 and 1500 kWh per year could therefore receive payments of about £200 to £300 per year, amounting to between £1400 and £2100 over 7 years.
Fuel savings during the first seven years might be between £400 (for mains gas) and £800 (for fuels like oil, LPG or electricity). The fuels savings will continue for many years beyond this, and will be worth more to you as fuel prices rise. Over 20 years, the fuels savings could be several thousand pounds.
For more on RHI support for domestic heating systems, please see our page How does the Renewable Heat Incentive support domestic installations?
Support for non-domestic solar thermal installations
Non-domestic solar thermal systems, e.g. for a B&B, a pub, a public swimming pool or industrial installations, have been covered under the RHI for a few years now. The non-domestic tariff from Jan 2016 is 10.28 pence per kWh (For systems smaller than 200kWth), paid over a 20 year period. So although this is lower than the domestic tariff it is for a much longer period.
To illustrate this, a hotel with a solar water heating system that creates 10,000kWh of useful heat per year would about £1000 in annual RHI tariff payments.
Tariffs are guaranteed over a 20 year lifetime and will be adjusted with inflation. All heat generated will have to be metered using heat meters for hot water or steam.
For information on RHI support for non-domestic installations, please see our page How does the Renewable Heat Incentive support non-domestic installations?