Certification bodies associated with Solar Thermal Systems

Written-by

Janet Richardson

Reviewed-by

Richard Burdett

Updated on

Jan 04, 2026

Certification bodies associated with Solar Thermal Systems

Quality assurance schemes for Solar Thermal

The main UK quality assurance scheme for low-carbon and renewable energy technologies is the Microgeneration Certification Scheme (MCS), now operated by MCS Service Company Ltd and supported by the Department for Energy Security and Net Zero (DESNZ). It is important to ensure that your solar thermal installer/supplier is accredited by an MCS-appointed certification body. MCS-accredited companies must conform to rigorous quality and safety standards and meet current consumer protection and competition requirements enforced by UK regulators. They should also offer you a written estimate of the likely energy output of the installation.

All renewable energy products are examined by certification bodies against MCS manufacturing and testing standards. The MCS also has an industry Code of Practice and works alongside TrustMark-approved consumer codes to support complaint resolution, rather than acting as the sole complaints handler.

For more information, visit the MCS website. Reputable renewable energy installation companies should also be a member of a TrustMark-approved consumer code such as HIES (Home Insulation & Energy Systems Quality Assured Contractors Scheme). Membership of HIES indicates that a company has signed up to its government-endorsed consumer code, which ensures high service standards before, during and after the installation of renewable energy technology. Members of HIES will not, for example, employ any ‘hard sell‘ sales techniques to induce a quick decision. Any sub-contractors engaged by installation companies must also comply with HIES and TrustMark codes of practice.

Details of the code of practice and a list of HIES-Registered companies can be found on their website. HIES operates independently but works alongside industry bodies, while the Renewable Energy Association (REA) remains a not-for-profit trade association which promotes renewable energy technology use. Many UK solar energy manufacturers, suppliers and installers are members of the Solar Trade Association (STA). The STA works closely with government departments including DESNZ on many policy areas. Visit the STA website.