Because the CO2 capture is inherent in chemical looping combustion (CLC), thus ideally avoiding costly gas separation, this process has potential for uniquely low costs of CO2 capture. The review reports on operational experiences with different oxygen carriers in CLC pilot operation. Further, the application to solid fuels is discussed in terms of technology challenges, routes for upscaling to commercial size, downstream gas treatment, options for achieving adequate circulation, and the use of biofuels in CLC to reach negative emissions. It is concluded that the necessary elements for a scale-up are at hand. Oxygen carrier materials of low cost have been tested in extended operation and found to have reasonable performance with respect to reactivity and lifetime. Designs for large-scale units have been performed, indicating that the process is technically realistic and should have a low cost of CO2 capture. A scale-up strategy to minimize risk and costs has been suggested.