Research on the optimal peak-to-valley electricity price considering the social cost of carbon emissions

With the proposal of the national “ 3060 “ double carbon goal, the peak-valley tariff setting should consider the important effect of the peak-valley price policy on emission reduction. Setting the peak-valley price reasonably can not only reduce the physical cost of the power grid, but also reduce the carbon emissions of power system. In this paper, the social cost of carbon emissions was considered for the first time in the process of peak-valley tariff setting, and the maximum optimized objective function of total social surplus including the optimal peak- valley ratio was constructed. The constraint conditions of the extreme value of objective function was determined by Lagrange multiplier method, the relationship between the optimal peak-valley tariff and electricity price, carbon price and marginal carbon emission factor was obtained. Taking the actual operation data of Guangdong power system from January to March, 2022 as an example, the marginal carbon emission factors in each period of peak and valley were estimated, and the optimal peak-valley price ratio1.78: 1: 0.3 considering the social cost of carbon emission was obtained. The study found that the current peak to valley price difference needs to be further increased after considering the society cost of carbon emission, and the optimal peak price ratio can be raised by 0.084, while the optimal valley price ratio can be decreased by 0.08.