Bigger Not Always Better for BECCS

Dev Kapadia ’23, Engineering, 7/7/20

(A) Traditional bioenergy production captures CO₂ during the plant growth and releases it back into the environment during combustion, resulting in a net zero carbon emission. (B) Bioenergy production through BECCS stores part of the CO₂ emissions from power plant production underground, making the process a “Negative Emissions Technology”

(Source: Wikimedia Commons)

In June of 2017, President Trump announced his intention to pull the United States out of the Paris Climate Agreement. The commitments of the agreement, signed in 2015, was adopted by nearly every nation with the goal of reducing global greenhouse gas emissions so that global temperature would be only two degrees Celsius above preindustrial levels by the end of the century.¹ With Trump’s intention of withdrawal, there is fear that this goal is in jeopardy. The silver lining, though, is that Trump cannot actually pull out of the agreement until November 4^th of 2020, which is after the next presidential election. Depending on the results of the election, another president could rejoin at the start of the next year and make the commitment against climate change within a month, before any radical changes occur.⁴

The impetus behind the Paris Agreement is still important to many Americans; according to the Pew Research Center, 64% of U.S. adults believe that protecting the environment should be a top priority for the government and 52% believe that correcting global climate change should be a top priority.⁶ These numbers are similar across the world, meaning that researchers worldwide are still putting significant efforts towards reducing the negative effects of climate change.

One of the energy alternatives that has been attracting interest as a renewable, more environmentally efficient alternative is the use of bioenergy with carbon capture and storage (BECCS). In BECCS, trees and grasses that are grown on land unsuitable for food crops are combusted to generate energy.⁶ BECCS is a subset of Negative Emission Technology (NET), a group of energy production methods in which the total CO₂ released in the atmosphere decreases. This occurs because CO₂ is captured from the environment and turned into energy in the form of chemical bonds. Combustion of BECCS crops releases energy and CO₂, but much of the CO₂ captured during the growth of these crops is captured, compressed, and stored underground.³

Many NETs are controversial due to unknown feasibility at larger scales as well as their unknown environmental impacts outside of soil sequestration (storage of CO₂ underground). A study led by researchers at the University of Southampton assessed the fitness of six potential locations in the UK for BECCS power plants. The researchers took into account the cost of transportation of biocrops, soil sequestration, flood mitigation, proximity to CO₂ storage sites, and welfare value (calculated by integrating costs and potential for environmental benefits). This last criterion was added in response to concerns that BECCS was only focused on reducing CO₂ emissions, leaving other aspects of environmental wellbeing at risk.⁶

The researchers concluded that a BECCS conversion of the Drax power station located on the River Ouse in the UK provided the best potential for success. However, at Drax and other power plant sites assessed, the researchers concluded that increasing the size of BECCS production puts increased burdens on the environments due to larger farming land and storage sites needed.² One of the goals put in place by the Paris Agreement and targeted by many of signatories of the agreement is to have zero emissions globally by 2050. In order for the UK to achieve that number, the government has a planned BECCS production of 15 GW which allows for the capture of 67 million tons of CO₂ per year.²Therefore, the researchers have concluded that BECCS conversion should be achieved with several smaller sites in order to minimize the environmental impact.⁶

These environmental impacts differ by site, so the team encourages environmental impact reports to be performed for every potential BECCS power station site. They hope that this research sparks more conversation on the potential impact of BECCS in global energy production and hopefully realigns global efforts towards greenhouse reduction during these uncertain times.⁶

References:

1. Denchak, M. (2018, December 12). Paris Climate Agreement: Everything You Need to Know. NRDC. Retrieved July 7, 2020, from https://www.nrdc.org/stories/paris     climate-agreement-everything-you-need-know
2. Donnison, C., Holland, R. A., Hastings, A., Armstrong, L.-M., Eigenbrod, F., & Taylor, (2020, June 29). Bioenergy with Carbon Capture and Storage (BECCS):          Finding the win–wins for energy, negative emissions and ecosystem services         size matters. GCB Bioenergy, n/a(n/a). https://doi.org/10.1111/gcbb.12695
3. Explainer: 10 ways “negative emissions” could slow climate change. (2016, April 11). Carbon Brief. https://www.carbonbrief.org/explainer-10-ways-negative     emissions-could-slow-climate-change
4. Johnson, K. (2019, November 5). Is the United States Really Leaving the Paris Climate Agreement? Foreign Policy. Retrieved July 7, 2020, from      https://foreignpolicy.com/2019/11/05/paris-climate-agreement-united-states          withdraw/
5. Funk C. & Kennedy B. (2020, April 21). How Americans see climate change and the environment in 7 charts. Pew Research Center. Retrieved July 7, 2020, from  https://www.pewresearch.org/fact-tank/2020/04/21/how-americans-see-climate     change-and-the-environment-in-7-charts/
6. Size matters for bioenergy with carbon capture and storage. (n.d.). ScienceDaily. Retrieved July 7, 2020, from https://www.sciencedaily.com/releases/2020/06/200629202014.htm