BECCS is an increasingly cited and researched negative emission strategy. BECCS has a simple working principle - carbon absorbed from the atmosphere is used by plants and trees to grow organic matter; this organic matter can be combusted to generate bio-energy (thermal energy). Carbon from the combustion process is captured rather than allowed to escape to the atmosphere, and is sequestered underground through CCS, resulting in a carbon negative process.

Combusting biomass to generate utility-scale electricity or heat are well-developed processes, but are currently achieved largely through co-firing with fossil fuels (Reid et al. 2020). Modifications can be made to the firing system and boilers to accelerate biomass combustion. A large amount of fossil generation would have to be replaced by biomass generation (with CCS) to meet carbon sequestration goals. 

In the IPCC Special Report on Climate Change and Land (IPCC 2019), several Shared Socioeconomic Pathway (SSP) scenarios model changes in cropland area based on assumptions about intensive agriculture, human population, diet, and other factors. All the scenarios significantly increase land set aside for bioenergy compared to present day, ranging from about 3 to 7 million km2 (300 - 700 million hectares). But critics of bioenergy often flag the implications of such expansion for agriculture, biodiversity, and conservation. 

Estimates of the amount of land required for BECCS biomass production depend on land availability and productivity assumptions and characterizations of what is considered sustainable. The medium confidence estimate of potential for BECCS is 0.4 to 11.3 GtCO2 removed per year – up to about a quarter of present day annual emissions. However, when further sustainability constraints are in place, the estimates are reduced (IPCC 2019). 

Cost estimates vary and are uncertain for all NETs primarily due to the lack of operations at scale, unproven technologies, and particularly for BECCS, unknown land productivity at higher temperatures due to climate change, land degradation, and other land use priorities. Fuss and colleagues estimate the cost of BECCS at 100-200 $/tCO2. The full range of BECCS costs in the literature is 15-400 $/tCO2, with extensive research underway on how to lower costs and develop successful use cases. The EU has several successful BECCS pilots including the Drax Carbon Negative Power Plant in the UK. 

Related AGCI Resources:

• Quarterly Research Review: Negative Emission Technologies and Land Use

• Quarterly Research Review: Latest Outlook on Biofuels