The costing approach applied here uses the aforementioned hybrid costing method, which combines engineering-economic bottom-up calculations of the cost of a FOAK plant and technological learning Email: jpy1@hw.ac.uk RCCS, Heriot-Watt University curve projections (a top-down method) to estimate how costs may develop as a result of mass deployment. The techno-economic assessment model is discussed in Section 7.1. The technical performance estimates are based on the existing literature for all but the solid sorbent technology, for which we used our own modelling, briefly discussed in Section 7.3. Because the impact of location on the economics of DACS is largely missing from the literature, we estimated DACS costs for seven geographically and economically diverse case study countries (United States, China, the United Kingdom, Germany, Brazil, Australia, and Oman) by assessing the variation of different economic parameters across these locations, detailed throughout Section 7.2. These case studies allowed us to explore siting decisions based on the availability of low-carbon energy sources, cost of materials and labour etc., whilst also acknowledging that complex factors beyond costs (e.g., political and geographic)