Biogas is a renewable energy formed from the natural breakdown of organic material in a process called anaerobic digestion. The high-energy gas produced can be converted to heat or injected into the national gas grid. Sufficient biogas is now being produced to power over 1 million homes in the UK. Solar 21 is developing a portfolio of AD plants in England availing of UK Government incentive schemes for the production of biomethane gas.

Biomethane-producing plants are eligible for the non-domestic Renewable Heat Incentive (RHI). Under this scheme, the UK government will pay eligible installations an incentive per cubic metre of biomethane and MWth (megawatt thermal) of heat produced. Payments will be index-linked for 20 years.