UK has potential for 180 TWh biomethane capacity by 2050: report

The UK could add as much as 180 TWh of biomethane production by 2050 to help tackle carbon emissions in both transportation and domestic heating, delegates at the Renewable Energy Association’s Biomethane as a Transport Fuel conference were told Thursday.

With current supply at 4TWh, the figure represents a best-case scenario and would only materialise after significant increases to green incentives that are in place.

Currently, the UK incentivises the development of biomethane capacity through the renewable heat initiative which pays 3p per kWh for displacing natural gas in heating, and the renewable transport fuel certificate (RTFC), which currently trades at 5.52p per kWh to encourage displacing gasoline in vehicles.

“It’s primarily in heavy goods vehicles that the real interest lies in the UK, and decarbonising this sector gives a real bang for the buck given the disproportionate amount of miles and emissions it accounts for,” conference chair Gaynor Hartnell of the Renewable Energy Association said in summarising the conference.

Emissions in the UK’s transport sector have plateaued since 1990, versus other sectors that have seen steady declines in greenhouse gas emissions.

Mike Foster, CEO of Energy and Utilities Alliance told delegates that UK GHG emissions had held at 120 million tons of carbon dioxide equivalent over the last 25 years and that pressure was mounting on the transport sector to tackle emissions that account for 24% of the entire country’s carbon footprint.

Switching heavy goods vehicle demand to gas would be a quick win, particularly in the light that CNG prices are around two-thirds per litre of the gasoline cost.

“You can see the mileage and the real momentum about gas vehicles for HGVs, buses and coaches. They can’t rely on electric and batteries, so there has to be some other combustion that takes place,” Foster told Energy Census.

However, the potential 180 TWh total includes a sizeable contribution from crops grown specifically for energy – a resource that is increasingly under scrutiny at both EU and UK government level as legislation moves towards favouring biofuel policies that promote waste use – such as synthetic natural gas from household waste.

Alongside that, delegates heard that the progress of biogas legislation in the transportation sector has been slowed by infighting between UK government departments – with both the Department for Transport and the Department for Business, Energy and Industrial Strategy keen to claim biogas as part of an emission-cutting strategy for transportation and domestic heating respectively.

However, with the RTFC offering an alternative revenue stream for biogas producers, the flexibility to switch between pushing gas into the grid for heating or into the transportation network may create additional demand for gas.

On the supply front, the government has said it will amend the Road Transport Fuel Obligation to mandate fuel suppliers to buy RTFCs from development fuels or pay 80p litre buy out charges.

While the targets start out low at 0.1% in 2019 and rise to 2.8% of 2032, one fuel supplier told Energy Census, “they rise over time and can be quite costly unless there is supply.”

Development fuels are classified as hydrogen-based, synthetic natural gas-based from pyrolysis, those that can be used in aviation and those that can be blended up to 25% and meet current gasoline and diesel specifications.

According to Energy Census price assessments, the Year 10 renewable fuel transportation certificate was valued at 20.2p, equating to 5.52 p on a kWh basis, meaning the option to put biomethane into the transportation network would net a producer 2.52 p more versus the 3pence/kWh the RHI guarantees.

Stuart Easterbrook of Cadent told the conference that bioSNG could supply a third of the UK’s domestic heating demand, or provide fuel for all 600,000 HGVs currently on the UK’s roads, while Martin Flach, Alternative Fuels Director at Iveco trucks said that 50% of their bus production is now for either gas-powered or hybrid vehicles.