Alternatives for decarbonizing existing USA coal power plant sites

A CO₂ capture and storage (CCS) retrofit strategy is compared to several repowering strategies for decarbonising existing coal power plant sites. The more promising repowering approaches analyzed seem to be a shift to natural gas via natural gas combined cycles and deployment of systems that coproduce synthetic liquid fuels plus electricity from coal and biomass with CCS. Under a wide range of plausible conditions, the latter option seems to the most promising approach for decarbonising these plant sites-exploiting simultaneously the carbon mitigation benefit of coprocessing biomass in CCS energy systems and the more general benefits offered by coproduction systems with CCS of: (i) low CO₂ capture costs, (ii) high efficiency of power generation, and (iii) large credits for the sale of the synfuel coproducts at current or higher oil prices, and (iv) very low minimum dispatch costs.