Thursday 26 April 2012

Coming out of the Shade - Will the Renewable Heat Incentive Provide a Much Needed Boost for Solar Thermal in the UK?

While the Feed in Tariff has been grabbing all the headlines, the government has quietly launched a similar cash-back scheme for solar heating in commercial applications, but where are the best opportunities?

At the end of 2011 photovoltaic solar energy was hardly out of the news, with legal challenges to the government’s management of the Feed in Tariff and a dash to install before tariff levels dropped.  Among all of this, it would have been easy to miss the fact that the government has launched a similar cash-back scheme for renewable heat technologies, including solar thermal.

The Renewable Heat Incentive
This solar heating installation for an Extracare building
would qualify for the Renewable Heat Incentive
Launched in November 2011, the Renewable Heat Incentive (RHI) is aimed at all buildings with installations of solar heating with the exception of single domestic premises.  It currently pays the owner of the solar system 8.9 pence per kilowatt-hour (kWh) of heat generated, with the tariff index-linked for the duration of the scheme.  The owner can claim the cash-back every quarter for 20 years from the date of registration.

Read a more detailed briefing on the scheme here.

Eligible buildings include commercial properties or groups of houses or apartments served by a single communal solar system.  Domestic buildings are intended to come under the scheme during summer 2013, with a consultation expected this September.
Where are the Opportunities?

Any building that has a need for hot water is an opportunity for solar thermal, but some are more attractive than others.  These include:


Accommodation for students at universities, junior staff at hospitals and pupils at boarding schools often have a centralised plant room where water is heated for distribution around the building.  It can be relatively straightforward to install a solar buffer tank to pre-heat the water for the existing heating system.  Sheltered accommodation and Extracare buildings are often heated in the same way, and if residents are assisted to bathe during the working day, then a smaller solar buffer tank can be used.

Apartment blocks can pose a more difficult challenge to the integration of solar water heating, especially if each apartment has its own individual heating system.  However solar heating systems which generate heat from a communal solar array and transfer it to hot water cylinders in individual apartments via a distribution ring are possible (see case study).


Hotels often have a high water demand, and if the occupancy of holiday accommodation is seasonally biased towards the summer months, then the effectiveness of a solar system can be higher due to supply matching demand.

Swimming pools are an excellent application for solar heating because the low demand temperature means the solar panels work at maximum efficiency.  Coupled to this, the large thermal capacity of the pool allows the full use of energy on sunny days, where storage capacity might limit the energy collection for a domestic hot water system.

Health Care

Hospitals and surgeries can have a high demand for hot water and centralised water heating systems, making for a more convenient retro-fit.

Industrial Process Heat

Industrial process heat represents a massive opportunity to deploy solar heating.  See earlier blog post: An Untapped Opportunity

With the advent of the Renewable Heat Incentive, the stage is set for heating companies to help their customers cost-effectively reduce fossil fuel use in a wide range of commercial heating applications.