we assume in our model that we have free waste heat with a 0% discount rate and no compression or storage costs, this value becomes $580-920 t-CO2 -1 , which is consistent with previous quotes from Climeworks. Then, if we extrapolate this using learning rates from the Hinwil to Orca scale, the range becomes $410-760 t-CO2 -1 . Previously, companies have paid up to $2050 t-CO2 -1 in voluntary CDR markets, suggesting there is a potential business case currently. The opportunities for these early cost reductions, such as using waste heat, will likely be exploited first leading to slightly lower costs than those predicted here for FOAK and early plants. However, when we reach large-scale deployment, these opportunities should have been fully utilised, leading to the scenarios predicted in our learning curves.