The use of bioenergy with carbon capture and storage (BECCS) to generate power “isn’t vital to meet net zero”, Green Alliance has cautioned.
The environmental think tank has urged the government to avoid “locking in” large-scale BECCS “too early,” saying its proposed extension of biomass subsidies beyond 2027 should be time limited.
In a new briefing, the Green Alliance said the UK’s plans for meeting its 2050 net zero target have so far relied on the large-scale future deployment of BECCS for electricity generation to provide the necessary level of greenhouse gas removal (GGR).
However, the think tank said this form of BECCS, which is being championed by Drax, is “controversial” and comes with “environmental risks”.
Green Alliance said BECCS is assumed in policy to be carbon negative at the point of combustion but this is only the case once the trees that were burnt are regrown, which can take “decades or even hundreds of years”. It said the harvesting of forests for biomass fuel can “long lasting and potentially damage to biodiversity” and creates competition for other land uses such as agriculture.
It also noted that the UK is reliant for imports for biomass fuel, “leaving the country exposed to significant uncertainty around future supply and costs.”
Furthermore, Green Alliance said the development of other options for GGR such as enhanced rock weathering and electrochemical ocean carbon removal “make it increasingly likely that the UK would be able to meet its GGR goals without resorting to power BECCS. If it was considered desirable, it could be possible to avoid using BECCS altogether once these options reach their maximum realistic potential.”
Enhanced rock weathering involves accelerating the natural process of silicate rocks reacting with CO2 in rainwater (carbonic acid), by spreading crushed silicate rock on open land: “The resulting carbonates are stable and capable of storing the CO2 over long time periods (over a thousand years).”
Meanwhile, electrochemical ocean carbon removal works similarly to direct air CCS (DACCS) but “requires less energy because CO2 is present in much higher concentrations in water than air.” Green Alliance said the technical potential of this technology is “enormous, with the only real limits being the speed at which processing plants can be built and the availability of renewable electricity to power them.”
The charity said both technologies are “highly scalable, provide lasting carbon storage, do not add significant additional pressures to the use of land and are particularly well suited to using resources available in the UK, rather than relying on imports.” It said they are also likely to be “cost competitive” with BECCS.
Green Alliance said the government should therefore “keep its options open” and invest in more GGR technologies to bring them to commercial readiness. It said BECCS should be treated as “one option amongst many”.
The government is consulting on proposals to extend the support for biomass generation provided through the Contracts for Difference and Renewables Obligation schemes beyond the current end of the subsidies in 2027.
Green Alliance said ministers should “avoid locking in large scale BECCS too early,” placing a time limit on any further subsidies to allow for a proper assessment on whether the technology is “the right option for the UK.”
As well as greenhouse gas removal, the think tank acknowledged that BECCS could provide a much-needed source of dispatchable power generation, but said its relatively merits should be weighed up against other options such as gas with CCS and hydrogen.
“If the government chooses to deploy power BECCS as a priority, it must use the fact that there are other GGR options to demand it is done sustainably and delivers value for money,” the briefing added.
At a minimum, Green Alliance the biomass used for BECCS should have a short carbon payback period, avoid putting additional pressure on natural habitats and biodiversity, avoid competing with food productions and avoid increasing the UK’s overseas environmental footprint.
A Drax spokesperson said: “This analysis fails to account for the fact that Power BECCS delivers both renewable power and carbon removals. BECCS is widely recognised to be an affordable and scalable solution that can be deployed in a timeframe that meets Government’s greenhouse gas removal target.
“Credible expert bodies, including the UN’s IPCC and the UK’s Climate Change Committee, agree BECCS is needed to address the climate crisis. The research does not spell out the cost of replacing the energy security Drax Power Station provides during a period when 7GW of secure generation is due to come off the system.”