Burning wood for power worse for climate than gas equivalent, report finds | Energy

Burning wood to generate electricity may be worse for the climate than burning gas, even when the resulting carbon dioxide emissions are captured and stored, according to new research.

The findings cast doubt on plans by several governments, including the UK, to offer grants or other financial support for carbon capture linked to wood burning.

Bioenergy with carbon capture and storage (BECCS) has been touted as a clean way to produce baseload electricity, replacing gas and coal, which could even result in “negative emissions” because when replacement forests are grown, they absorb CO2 from the air.

But such systems could take 150 years to be “carbon negative”, researchers from the US, UK and China have found, partly because of the time it takes for forests to regrow and because of the damage caused when existing savannah, pasture or cropland is converted to produce biomass for burning.

Burning wood from existing forests, especially old-growth areas, also proved problematic, but even when it was estimated that half the wood came from waste sources and half from fast-growing plantations, models found that it took decades to reach “negative emissions.”

The scientists, who describe their work in the peer-reviewed journal Nature Sustainability, used data modeling techniques to show that most emissions from burning wood were generated before they reached the power station and therefore could not be captured. Wood can emit twice as much carbon per unit of energy produced as fossil gas and is much less efficient at producing energy.

Tim Searchinger, a senior researcher at Princeton University, who led the study, said: “Governments should not subsidize the burning of wood from existing forests, with or without carbon capture and storage. This would increase carbon emissions for decades, even if nothing was done, and would significantly raise energy prices for people.”

“Governments should reform laws that state that carbon emitted from chimneys when burning wood does not count – in other words, does not contribute to global warming. It does.”

Campaigners said governments should stop producing electricity from wood. In the UK, the main producer of electricity from biomass is the Drax power station, the largest source of CO2 emissions in the country. Drax received almost £1 billion in subsidies last year to burn wood, according to estimates by a think tank this week.

Douglas Parr, chief scientist at Greenpeace UK, said: “Common sense tells you that cutting down trees to burn them and then burying the resulting carbon emissions is a bad idea. This scientific study confirms that. Removing trees from one country to balance our UK carbon budget leaves the whole world poorer.”

Matt Williams, a senior forest advocate at the Natural Resources Defense Council, said the new findings support research he and others conducted last year. “The UK is better off without BECCS,” he said. “We need to find other sources of truly clean energy that do not rely on imported fuels. »

Drax has “paused” its investment in BECCS, citing a lack of certainty over government subsidies for the technology. A Drax spokesperson said: “We agree that biomass for BECCS and bioenergy should not be sourced in the way described in the document, which assumes that the entire harvest is used for BECCS or bioenergy. We only source from sustainable, well-managed forests, including sawmill residues, poor quality roundwood and forestry residues.”

“We also recognize the need for our biomass to deliver positive outcomes for climate and nature, which is why we monitor the forests we source from and invest in tools to improve supply chain transparency, such as our biomass tracking system. »

They added: “We are not aware of any managed forest areas where the type of harvesting described in the document would be economically viable for land managers, let alone for BECCS and the bioenergy industry. Existing BECCS methodologies – including ours – have strict sustainability requirements in place that would not allow materials harvested in the manner described to be used for the generation of verified carbon removal credits.”

Trevor Hutchings, chief executive of the Renewable Energy Association, a trade body whose members include the biomass industry, noted that the UK government’s plans to achieve net zero emissions by 2050 relied on BECCS and other forms of carbon capture.

“The paper highlights many of the complexities and risks associated with BECCS, but it is important to recognize that, without BECCS and other forms of negative emissions, we will not meet our legally binding net zero targets,” Hutchings said.

He added: “It is clear that the life cycle emissions of BECCS are highly dependent on the choice of feedstock, with waste, residues and other biogenic sources providing significantly different outcomes. The focus should be on the sustainable deployment of BECCS within a wider renewable energy system that enables emissions reductions, energy security and affordability.”

A spokesperson for the Department of Energy Security and Net Zero rejected the report’s findings. “We do not recognize these claims,” they said. “No final decision on the deployment of large-scale bioenergy with carbon capture and storage projects has been made, and any support should ensure value for money for taxpayers and meet our sustainability criteria.”