Development of a Capacity Allocation Model for the Multi-Energy Hybrid Power System

The application of multi-energy hybrid power systems is conducive to tackling global warming and the low-carbon transition of the power system. A capacity allocation model of a multi-energy hybrid power system including wind power, solar power, energy storage, and thermal power was developed in this study. The evaluation index was defined as the objective function, formulated by normalizing the output fluctuation, economic cost, and carbon dioxide emissions. Calculations under different initial conditions and output electric power scenarios were carried out with genetic algorithm. The capacity allocation model was validated with the literature results, with errors of less than 5%. Results indicate that the capacity allocation modes of the multi-energy hybrid power system can be divided into thermal power dominated mode, multi-energy complementary mode, and renewable power dominated mode. In addition, the division of capacity allocation modes is not affected by the weather conditions and energy storage ratio. The capacity factor decreases from 0.4 to 0.24 as the power system changes from the thermal power dominated mode to the renewable power dominated mode. When the output electric power is 240 MW, 300 MW, and 340 MW, the optimal energy storage ratio is 10%, 18%, and 16%, respectively. The model developed in this study not only enriches the theory of multi-energy complementary power generation but also guides the engineering design of the wind-photovoltaics-thermal-storage system targeting smart grid and be beneficial for the middle-long-term planning of the green and low-carbon transition of the power system.