The historical focus of renewable energy policy in the UK, as in most nations, has been on supporting deployment in renewable energy sources of electricity. The adoption of ambitious EU wide targets for renewable energy has forced greater consideration of renewable energy sources of heat (RES-H). The UK pushed ahead rapidly in considering different policy options and legislating a new instrument, the Renewable Heat Incentive (RHI) to support RES-H, a form of tariff mechanism designed with the specifics of RES-H in mind, though translation into application has been slow. The evolutionary process which led to the current policy instrument is considered, along with the need to consider other elements to work with it. This represents a new and novel application of policy to an area where there are few examples of large-scale policies which go beyond direct capital subsidy. (C) 2014 Elsevier Ltd. All rights reserved.