The Department for Business, Energy and Industrial Strategy (now DESNZ) commissioned a consortium led by CAG Consultants to undertake an evaluation of the reformed Renewable Heat Incentive.  CAG Consultants led design of the evaluation, including the theoretical framework, and led on qualitative research. CAG also coordinated inputs from workstreams involving surveys of RHI applicants, cost-effectiveness analysis, sustainable market assessment and quasi-experimental analysis of the effectiveness of RHI reforms.

How we delivered the project

CAG Consultants developed an overarching theory of change for the reformed RHI, and worked with the client to identify priority topics for in-depth research. The research focused particularly on the impact of RHI reforms introduced in 2017. For the domestic scheme the reforms included tariff changes, heat demand limits, metering requirements and ‘Assignment of Rights’, while for the non-domestic scheme they included the restructuring of biomass tariffs, the removal of drying from eligible heat uses, a 50% waste requirement for biogas and biomethane feedstocks, the introduction of deemed heat demand for ‘shared ground loop heat pumps’ and the introduction of tariff guarantees for certain categories of large and complex projects.  

A detailed ‘realist’ approach was used to explore priority topics in-depth, involving exploration of ‘what worked for whom, why and in what circumstances’. Successive waves of realist qualitative research focused on schemes involving air source, ground source and water source heat pumps, including shared ground loop technology, as well as biomass and biomethane schemes. This involved hundreds of interviews with RHI applicants, non-applicants, installers and equipment manufacturers.

The scale and complexity of this evaluation were challenging. CAG worked closely with partner organisations to synthesise evaluation findings and ensure that findings from different workstreams were carefully integrated in relation to the client’s priority topics. Triangulation between the views of installers, applicants and external stakeholders was used to reduce potential bias in the findings.

Objectives achieved

The overall findings from this evaluation were summarised in two published synthesis reports, one focusing on the domestic RHI and one on the non-domestic RHI. The RHI was found to have significant impact on the take-up of renewable heat, particularly in off-gas grid areas, but some sections of the market were found to require further Government support to become self-sustaining. Client feedback, after the end of the project, indicated that CAG’s qualitative research was very high quality and that the synthesised research findings showed a good understanding of the reformed RHI.

For further information, please contact Denny Gray at dg@cagconsult.co.uk