THERE WAS a collective sigh of relief from the UK's green gas sector last month as the government reversed earlier cuts to the Renewable Heat Incentive.

With higher tariff levels restored, industry pundits predicted that this 'vital boost' for green gas technology would prompt a fresh boom in the construction and commissioning of anaerobic digestion plants, which generate biomethane through breaking down organic wastes and purpose-grown energy crops.

Following the passing of the relevant legislation through Parliament, AD plant operators are now able to claim a restored tariff of 5.6p per kWh of renewable heat generated for their Tier 1 biomethane – the first 40,000 MWh they inject into the grid per year. Once plants are commissioned, they will receive a guaranteed tariff level for twenty years.

Deployment of new green gas plants in the UK has been falling in recent years in line with decreasing RHI tariffs. Following the turnaround, it is forecast that as many as 40 plants may be built over the next two years, generating up to an additional 2 TWh of renewable heat per year.

The green gas industry is already contributing over 4 TWh of gas per year, but with the right support has the claimed potential to meet around 15% of total UK gas consumption and heat 30% of UK households. However, the restored RHI tariff will only support new renewable heat projects until 2021, with no further support promised from government beyond the current RHI budget allocation.

Anaerobic Digestion and Bioresources Association chief executive Charlotte Morton said: “Green gas produced through AD not only produces much lower levels of emissions than natural gas but is also home-grown, allowing the UK to increase its energy security and be less reliant on energy imports from abroad. AD is already reducing gas imports by 2% and has the potential to reduce them by as much as 16%.

“The restored RHI tariffs will give a vital boost to the AD industry’s ability to produce green gas over the next few years, but with emissions from heat accounting for a third of all UK greenhouse gas emissions and no clear government strategy yet identified for decarbonising heat, it is imperative that the government commits to long-term support for green gas beyond 2020 while the industry works to bring down costs to become financially self-sufficient.”

Managing director of green gas producer Future Biogas Philipp Lukas commented: “We are pleased that the updated RHI has finally seen the light of day. In these turbulent times there was always the risk that the government simply wouldn’t find the time – or indeed wouldn’t be around!

"Hopefully this modest reboot can help the industry continue its impressive trajectory. That way we can demonstrate AD is needed to counter issues around decarbonising heat and transport, address security of supply issues – amply demonstrated during the cold snap – and recycle organic wastes to make energy and fertilise crops.”

Director at AD service company BioG UK, Rob Greenow, added: “BioG UK welcomes the new RHI, which allows a continued push to develop AD plants across the UK. With the aim of clear rules and management of the Tariff Guarantee process, this should give the AD market the boost it needs over the next couple of years.”

The impact of the new tariffs on the green gas industry will be a key topic of discussion at UK AD and World Biogas Expo 2018 at the NEC in Birmingham on July 11 and 12, the largest dedicated global biogas tradeshow in the world.