present some preliminary analysis of the impact of FOAK plant size on the learning curves. Across the plant sizes studied, the initial size of the solid sorbent and KOH-BPMED technologies has little impact on the Gt-CO2 year -1 scale cost projections, but the solid sorbent FOAK costs are affected. For the MgO ambient weathering and KOH-Ca looping technologies, the 1 Mt-CO2 year -1 and 0.5 Mt-CO2 year -1 FOAK plant size learning curves overlap almost perfectly. However, decreasing the FOAK plant size Email: jpy1@hw.ac.uk RCCS, Heriot-Watt University further to 0.1 Mt-CO2 year -1 dramatically impacts both the FOAK and Gt-CO2 year -1 scale costs negatively, indicating that the FOAK plants for these technologies should ideally be built at large scales.