Optimal allocation method of energy storage for integrated renewable generation plants based on power market simulation

This study designs and proposes a method for evaluating the configuration of energy storage for integrated renewable generation plants in the power spot market, which adopts a two-level optimization model of “system simulation + plant optimization”. The first step is “system simulation” which is using the power market simulation model to obtain the initial nodal marginal price and curtailment of the integrated renewable generation plant. The second step is “plant optimization” which is using the operation optimization model of the integrated renewable generation plant to optimize the charge-discharge operation of energy storage. In the third step, “system simulation” is conducted again, and the combined power of renewable and energy storage inside the plant is brought into the system model and simulated again for 8,760 h of power market year-round to quantify and compare the power generation and revenue of the integrated renewable generation plant after applying energy storage. In the case analysis of the provincial power spot market, an empirical analysis of a 1 GW wind-solar-storage integrated generation plant was conducted. The results show that the economic benefit of energy storage is approximately proportional to its capacity and that there is a slowdown in the growth of economic benefits when the capacity is too large. In the case that the investment benefit of energy storage only considers the income of electric energy-related incomes and does not consider the income of capacity mechanism and auxiliary services, the income of energy storage cannot fulfill the economic requirements of energy storage investment.