This paper creates a technology roadmap for China's electricity sector on CO2 mitigation based on cost‐effective analysis (CEA) and cost‐benefit analysis (CBA). We use mitigation targets for 2020 and 2030 to determine the required implementation degrees of 13 selected power‐generating technologies. According to the initial investment, operational costs, and external costs of major pollutants, we assigned a priority rank to each technology, which is derived on the basis of internal costs and social costs. A comparison of present value costs of major generating technologies shows that hydroelectricity bears the highest total cost, while cogeneration of heat and power bears the lowest cost. The technology with the highest total social benefit is also hydroelectricity, while carbon capture and sequestration (CCS) yields the lowest social benefit. By 2030, 6 of the 13 technologies can realize net internal benefits and all 13 technologies except CCS can realize net social benefits. The top three technologies based on internal levelized cost are: cogeneration of heat and power, biomass power generation, and wind power generation. Based on social levelized cost, the highest priority technologies are: integrated gasification combined cycle, biomass power generation, and wind power generation. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd