Broader contextThis analysis highlights the merits of making low-carbon liquid fuels thermochemically rather than biochemically by simultaneously: (i) capturing and storing CO2from biomass to increase its carbon-mitigation potential; (ii) co-processing biomass with coal to exploit the scale economies of coal conversion, the low cost of coal as a feedstock, and, with CO2capture and storage (CCS), the reduced amount of biomass needed to make low-carbon fuels relative to conventional biofuels; and (iii) producing electricity as a major co-product to increase energy conversion efficiency and reduce capital costs relative to separate systems for producing liquid fuels and electricity. It shows the strategic importance of simultaneously pursuing carbon mitigation for transportation fuels and electricity and that the pursuit of carbon mitigation and energy security goals for transportation fuels need not be in conflict. Although the approach involves radically different energy system configurations from systems currently in use, the systems described involve components that are either already commercial or could become commercially available during the next decade. Requirements are: (i) demonstration that CCS is viable as a major carbon mitigation option, (ii) commercialization of large biomass gasifiers, and (iii) commercial-scale demonstrations of co-production systems that co-process coal and biomass with CCS.