Gas has only limited role as ‘bridging fuel’

THE UK Energy Research Centre (UKERC) says that gas only has a limited role as a “bridging fuel” to a low-carbon future, unless CCS is deployed.

Various governments, including the UK’s, have touted gas, which undoubtedly has lower carbon emissions than other fossil fuels such as coal, as the best option for reducing emissions until renewable sources of energy become more efficient and widespread. The UK has a legally-binding greenhouse gas emissions reduction target of 80% compared to 1990 levels by 2050. Amber Rudd, the energy and climate change secretary, recently announced that by 2025, the country would phase out coal-fired power stations and replace them with gas-fired generation as part of efforts to meet the target.

However, UKERC’s report, The future role of natural gas in the UK, says that without CCS, gas use in the UK can only be around 12% of the 2010 level if the UK is to meet its 80% reduction targets. From the 2030s onwards, new combined cycle gas turbine (CCGT) gas-fired power stations will have to operate at very low load factors.

The report’s authors explored several scenarios to reach their conclusions, including “Abandon”, where the Climate Change Act is repealed; “Affordable”, where a 60% reduction by 2050 is achieved; “Maintain”, where the 80% reduction target is achieved with no new coal and CCS is deployed; and “Maintain (tech failure)”, where the target is achieved but without CCS. They used computer modelling to explore each one.

The authors write: “Our analysis shows that gas could only act as a bridge from 2015–20. We therefore conclude that gas is more likely to provide a short-term stop-gap until low- or zero-carbon energy sources can come onstream.”

They say that the UK government’s recent decision to abandon its CCS funding competition is “at odds” with its notion that gas will help the UK to meet its carbon targets, unless it hopes the technology will be developed elsewhere and imported. The low load factors CCGT plants without CCS will need to operate at will make them uneconomic to run.

“Without CCS, there is little scope for gas use in power generation beyond 2030 and it will need to be steadily phased out over the next 35 years, and almost entirely removed by 2050. This represents a major challenge in relation to the decarbonisation of domestic heat, and undermines the economic logic of investing in new CCGT gas plants rather than low- or zero-carbon generation in the first place,” said UKERC director Jim Watson.