Compliance with long term climate targets whilst maintaining energy security is understood to rely
heavily on the large-scale deployment of negative emissions technologies (NETs). One option,
Bioenergy with Carbon Capture and Storage (BECCS) is prominent in Integrated Assessment
Models (IAMs), with projected annual contributions of 8 – 16.5 Gt
CO
2
/yr of atmospheric carbon
dioxide removal whilst contributing 150 – 300 EJ/yr, or 14 to 20% of global primary energy supply,
in 2100. Implicit in these scenarios is the assumption that BECCS is a net producer of energy.
However, relatively energy intensive biomass supply chains and low power generation efficiency
could challenge this ubiquitous assumption. Deploying an energy negative technology at this
scale could thus represent a threat to energy security. In this contribution, we evaluate the energy
return on investment (EROI) of an archetypal BECCS facility. In order to highlight the importance
of biomass sourcing, two feedstock scenarios are considered: use of domestic biomass pellets
(UK) and import of biomass pellets from Louisiana, USA. We use the Modelling and Optimisation
of Negative Emissions Technologies (MONET) framework to explicitly account for growing, pre-
treating, transporting and converting the feedstock in a 500 MW BECCS facility. As an example,
we illustrate how the net electricity balance (NE
l
B) of a UK-based BECCS facility can be either
positive or negative, as a function of supply chain decisions. Power plant efficiency, fuel efficiency
for transport, transport distance, moisture content, drying method, as well as yield were identified
as key factors that need to be carefully managed to maximise BECCS net electricity balance. A
key insight of this contribution is that, given an annual carbon removal target, increasing BECCS’
power generation efficiency by using a more advanced biomass conversion and CO
2
capture
technology could improve BECCS net electricity balance, but at the cost of increasing the amount
of BECCS capacity required to meet this target. BECCS optimal deployment pathway is thus
heavily dependent on which service provided by BECCS is most valued: carbon dioxide removal
or power generation.