The government should not subsidise large biomass power plants and lower bioenergy adoption targets if carbon capture and storage (CCS) technology is not developed quickly, according to the Committee on Climate Change (CCC).
In a report examining how using biomass and biofuels can help to decarbonise the UK’s energy supply, the government select committee warns that without effective CCS the lifecycle emissions and broader environmental impacts associated with growing bioenergy crops could outweigh their potential carbon benefits.
The CCC concludes that bioenergy could provide 10% of the UK’s total energy needs by 2050, contributing significantly to the CO2 reductions needed to meet the government’s fourth carbon budget, but even at this level policymakers may be faced with having to choose between potential carbon savings and wider environmental objectives, such as protecting biodiversity.
CCS technology offers the potential to create negative CO2 emissions, but without it the amount of biomass needed to lower emissions in line with the carbon budgets would result in unsustainable land use change, threatening biodiversity and food supply.
The committee concludes that without CCS, bioenergy should be restricted to heat generation for energy-intensive sectors and to biofuels for the aviation and shipping sectors, and not used for large-scale energy generation.
According to the report the most effective use of biomass crops is in the construction sector by replacing energy-intensive materials, such as concrete and steel, with wood that absorb CO2 while growing and then lock it into buildings, rather than releasing it back into the atmosphere when its burned.
The use of biomass and biofuels in decarbonising energy is highly controversial confirms David Kennedy, chief executive of the CCC.
“There is a crucial role for bioenergy in meeting carbon budgets, but within strict sustainability limits – trade-offs with wider environmental and social objectives may be needed,” says Kennedy.
The report recommends that the government withdraw its offer to subsidise new large-scale biomass plants under the Renewables Obligation, saying that such plants are both unsustainable and expensive. Support for biomass generation should be limited to conversions of existing coal plants and sites which burn both coal and biomass.
It also calls on the government to urgently support the development of CCS technologies to demonstration level and to revise existing legislation to improve the sustainability of biofuels.
The committee argues that current regulation does not effectively account for the full lifecycle emissions of biomass and should also tighten the benchmark emissions levels for biomass from 285g/CO2kWh to 200g/CO2kWh.
The CCC’s report came as climate change secretary Chris Huhne was challenged over the government’s commitment to CCS by Tim Yeo, chair of the Energy and Climate Change Committee.
In an open letter, Yeo asked for clarification of whether the £1 billion of government funding earmarked for supporting the UK’s first CCS demonstration programme was still available, following rumours that it could be allocated more widely to infrastructure projects.
"Without [CCS}, we may face an impossible trade-off between our environmental objectives and energy security,” wrote Yeo.
“We are extremely concerned that the Treasury's short-term fixes will endanger our long-term economic and environmental prospects and these issues are not being given the weight they deserve in Whitehall.”
In October, the government withdrew financial support from the only CCS demonstration project that remained in the running for the £1 billion funding after three other projects withdrew. It was decided by DECC, that the Longanett scheme did not provide value for money for the taxpayer and the money would instead be dedicated to new projects.
