Biomass energy with carbon capture and storage (BECCS): a review.

This is a review paper intended to provide an overview of debates relating to BECCS or bio-CCS, which are alternative terms for the coupling of bioenergy with carbon capture and storage (CCS). The paper follows from a workshop held in December 2009, hosted by the Scottish Centre for Carbon Capture and Storage at the University of Edinburgh, organised by Tyndall Manchester at the University of Manchester and funded by the Tyndall Centre. The principal rationale for BECCS is that whereas the current atmospheric concentration of CO2 is more than 380ppmv and rising, achieving the European policy aspiration of not exceeding a global temperature rise of 2?C is likely to require atmospheric concentrations of below 350ppmv CO2e. In theory, BECCS has the potential to help to bring the atmospheric CO2 concentration to below present levels, or at least to contribute to its reduction by delivering ?negative emissions?. By capturing and storing the CO2 absorbed from the atmosphere by bioenergy feedstocks, BECCS can, in theory, deliver power and heat production with net negative emissions. Yet, while BECCS enthusiasts have drawn support from scenarios of large scale global bioenergy supply and its co-option into BECCS systems, the assumptions of sufficient accessible CCS capture, pipeline and storage infrastructure and that large scale bioenergy supply can be reconciled with competing uses of land (and water) are both uncertain. While biomass co-firing with coal offers an early route to BECCS, a quite substantial (>20%) biomass component may be necessary to achieve negative emissions in a co-fired BECCS system (a percentage that is dependent, of course, on system assumptions). Financially, significant incentives will be necessary to establish either BECCS or CCS; neither are currently competitive in Europe, given carbon prices within the EU ETS which is also not currently designed to credit negative emissions. Nonetheless, in cost terms, bioenergy compares well with other carbon abatement options, particularly if wastes or residues are used as fuel, and modelling suggests that BECCS would be an important component of energy systems intended to reach 350pmv CO2e. We judge that BECCS can and likely will play a role in carbon reduction, but that care needs to be taken to minimise the risks of disincentivising inherently low carbon energy systems via lock-in of fossil CCS. Care also needs to be taken not to exaggerate the potential of BECCS, given that (a) there are few studies of the cost of connecting bio-processing (combustion, gasification or other) infrastructure with CO2 storage sites; and (b) that scenarios of global bioenergy potential remain contentious.