Solar Heat in the United Kingdom
Status of the Market for Solar Heat
Market Size and Trends
Although solar thermal receives the highest Renewable Heat Incentive (RHI) tariff (see section on Support Framework), the number of installations in the UK have been falling in recent years. In 2016, just over 10,000 m2 of solar water heating collectors were installed, down from 90,000 m2 at its peak in 2010 (Solar Trade Association, 2017), however figures from 2017 suggest that this decline has stopped.
Data on the contribution of solar thermal to the UK energy system is available from the Digest of United Kingdom Energy Statistics (DUKES). Since the launch of the UK Domestic Renewable Heat Incentive scheme in April 2014, around 8,000 domestic solar thermal installations have been accredited, which equates to around 22.5 MWh of solar thermal heat.
Typical Applications and Products
Typical solar thermal applications in the UK are domestic hot water systems for houses and swimming pool heating. Domestic hot water systems are generally forced circulation systems with 150 to 250 litre tanks and 2 to 5 m2 of flat plate or evacuated tube collectors. Flat collectors account for the larger share of the market; many of these systems are roof-integrated which are designed to replace roof tiles.
Several metal cladding companies offer active solar air heaters as part of their product portfolio. Since their introduction to the UK market in 2005, approximately 14,000 m2 have been installed, with the largest being a 4,334 m2 collector installed on the Marks & Spencer (M&S) distribution centre at Castle Donington.
Main Market Drivers
In the case of new build housing, building regulations focus on carbon emissions rather than energy consumption; with the availability of relatively low carbon gas delivered through a comprehensive national network and relatively high carbon electricity, small solar photovoltaic (PV) systems can often help meet carbon emissions targets more cost effectively than solar thermal and so have become the favoured approach when selecting a solar technology to help meet regulations, except for off the gas grid where solar thermal is a more competitive solution.
Another significant challenge for solar thermal water heaters in new housing in the UK is the popularity of wall hung instantaneous natural gas combination boilers (combi-boilers), which do not require a hot water tank. New UK houses are the smallest in Western Europe (Royal Institute of British Architects, The Case for Space: the size of England's new homes) which can make installing a new hot water cylinder a challenge. Solar thermal systems with small hot water tanks which are designed to pre-heat the cold water supply for a combination boiler are available in the UK. Another challenge is the competition for roof space from the increased deployment of roof-mounted PV. Several UK companies offer PV power diverters, which will divert excess PV generation into a hot water tank immersion heater.
With regard to the market for retrofit of renewable energy systems within existing UK houses, one of the significant market drivers has been a proportion of home-owners wanting 'to do the right thing'. However, for a variety of reasons (which include the availability of a Feed-in-Tariff, system simplicity and effective marketing) solar PV has proven to be a more popular choice within this sector of the market than solar thermal.
Public opinion of solar thermal, and renewable energy in general, is very positive in the UK. The BEIS Energy and Climate Change Public Attitudes Tracker (PAT), which has been tracking public opinion on energy related issues since March 2012, has shown consistently that around 80% of the public support renewable energy.
Public awareness for solar thermal in particular is strong (highest among the renewable heat technologies), however, only 7% of those surveyed, and who were aware of renewable heat, are considering installing solar thermal in the near future. The main reasons for not installing solar thermal were the perception of high installation cost (26 %) and survey respondents not owning their own property (25 %).
Other Key Topics
Status of the Market for Solar Buildings
- IEA SHC || IEA SHC || Solar Heat Worldwide Markets and Contribution to the Energy Supply (no date). Available at: http://www.iea-shc.org/solar-heat-worldwide (Accessed: 11 May 2019).