Solar Thermal: “Potential Massively Underestimated”
 Solar Thermal: “Potential Massively Underestimated”

Solar Thermal: “Potential Massively Underestimated”

The UK Department of Energy and Climate Change (DECC) has recently published its Renewable Energy Strategy (RES) which includes solar thermal. This has provoked a strong response from the UK Solar Trade Association (STA) stating that DECC has “massively underestimated the potential of solar thermal technologies and completely missed a huge opportunity”.

The full details of the RES include supporting documents which indicate a decision to dramatically cut the proportion of renewable heat estimated to be provided by solar thermal in the future. In particular, one report entitled “The Supply Curve for Renewable Heat” outlines potential scenarios for increasing renewable heat contributions in the UK to up to 12% by 2020. This concludes that while a mix of technologies is needed to meet EU targets, the cost per unit output of solar thermal is higher than was found in previous work, significantly exceeding that of other renewable heat technologies.

The report provides an overview of the expected supply curves, which estimate the total additional renewable resources from all renewable heat technologies as a base case at around 46 TWh by 2020, i.e. 8.5% of UK’s total primary heat demand. It is suggested this can be achieved at a resource cost of less than 100 Pounds Sterling (GBP)/ MWh, which could be achieved almost entirely through large-scale biomass boilers and air-source heat pumps. Only in higher growth scenarios is solar thermal shown to contribute 5-6 TWh but at a cost exceeding £ 150 GBP/MWh. The report concludes that when cost per unit output is above 100 GBP/MWh then there is relatively limited additional renewable heat potential available. It goes on that “all of solar thermal’s potential appears above 150 GBP/ MWh,” which reflects “the very high costs associated with solar thermal heating.” The additional renewable resource (ARR) is a measure of the contribution to the UK’s renewable energy targets under EU legislation.

The STA has argued that the document’s subsequent recommendation to downgrade solar technology is “retrogressive”, and claims that this report was based on a 2008 study carried out by UK consultants Element Energy and entitled ‘The Growth Potential for Microgeneration in England, Wales and Scotland’, which was ‘totally discredited’ by the solar thermal industry. The STA maintains that the study used inaccurate data estimates, “written with what we understand was baseline rather than upper and lower limits data.”

The UK Renewable Energy Strategy can be found here:

The report “The Supply Durve for Renewable Heat” can be downloaded here:

The Solar Trade Association’s press release can be found here:


Chris Laughton

Chris Laughton is Founder and Managing Director of the Solar Design Company in Great Britain.