Negative emissions technologies (NETs) in general, and bio-energy with carbon capture and storage (BECCS) in particular, have been identified as key technologies in the context of limiting climate change to no more than 1.5 â 2Â°C (Fuss et al.
, 2014). By actively removing CO2
from the atmosphere, NETs provide a service, and thus investors would expect an appropriate risk-adjusted rate of return, varying as a function of the quantity of public money involved. In addition to providing negative emissions, BECCS facilities also generate firm low carbon power. However, as the electricity sector is integrating an increasing share of intermittent renewable energy (iRE), such as wind and solar, the dispatch load factor of such BECCS facilities may be small relative to their capacity. This has the potential to significantly underutilise these assets for their primary purpose of removing CO2
from the atmosphere. In this study, we present a techno-economic-environmental evaluation of BECCS plants with a range of operating efficiencies, considering their full- and part-load operation relative to a national-scale annual CO2
removal target, electricity price and negative emissions credit. We find that in all cases, a lower capital cost, lower efficiency BECCS plant is superior to a higher cost, higher efficiency facility from both environmental and economic perspectives. We show that it may be preferable to operate the BECCS facility in base-load fashion, constantly removing CO2
from the atmosphere and dispatching electricity in a demand-following manner. We show that the use of this âspare capacityâ to produce hydrogen for, e.g
., injection to a natural gas system for the provision of low carbon heating, can add to the overall environmental and economic benefit of such a system. The sensitivity of the model to biomass carbon footprint is also presented. The only point where our conclusions are altered is where the CO2
emissions associated with the biomass supply chain are sufficiently large so as to eliminate BECCS CO2
removal (Mac Dowell & Fajardy, 2017).
Fuss, S., Canadell, J. G., Peters, G. P., Tavoni, M., Andrew, R. M., Ciais, P., Jackson, R. B., Jones, C. D., Kraxner, F., Nakicenovic, N., Le Quere, C., Raupach, M. R., Sharifi, A., Smith, P. & Yamagata, Y. (2014). Betting on negative emissions. Nature Climate Change, 4 (10), 850â853. https://doi.org/10.1038/nclimate2392
Mac Dowell, N., & Fajardy, M. (2017). Inefficient power generation as an optimal route to negative emissions via BECCS. Environmental Research Letters, at press: https://doi.org/10.1088/1748-9326/aa67a5