In China, electricity market reform was first implemented in 2015. At the same time, the national carbon market was built, along with the electricity industry, which was considered a breakthrough. Some key considerations for the future development of China’s electricity system include the implementation of demand-side measures in order to adjust the peak-to-valley difference and the economic dispatch of increasing intermittent renewable energy and traditional energy in the process of power marketization with the implementation of a carbon policy. This paper examines the impact of policies on electricity generation by modelling the evolution process of power marketization and the economic dispatch of generation technologies over a sixteen-year period beginning in 2020. We model four potential influencing factors of government policy: (1) the demand response mode; (2) power marketization process; (3) capacity adjustment of thermal power units; and (4) carbon taxes, which vary in terms of their timing and amount. This model assesses the impact of these influencing factors on the competition between electricity generators using a range of output variables, including generation portfolios, electricity prices, capacity factors, CO2 emissions, etc. The results show that the new round of electricity market reforms has had a positive impact on renewable energy generation. The influence of carbon policy is evident in the promotion, transformation and elimination of thermal units, and an indirect increase in renewable energy generation.