Optimization Operation of Power Systems with Thermal Units and Energy Storage Considering Lifetime Loss and Thermal Units Deep Peaking

Deep peak shaving achieved through the integration of energy storage and thermal power units is a primary approach to enhance the peak shaving capability of a system. However, current research often tends to be overly optimistic in estimating the operational lifespan of energy storage and lacks clear quantification of the cost changes associated with system peak shaving. This study proposes an optimized operation model for the joint operation of thermal power and energy storage while considering the lifespan degradation of energy storage and the deep peak shaving of thermal power. This model measures the cost changes due to the participation of energy storage in thermal power unit peaking. It is able to reflect the value of economic externalities of energy storage in the power system and has a positive reference effect on energy storage investment planning and energy storage subsidy pricing. First, an energy storage lifespan degradation model based on equivalent cycle counts is constructed, along with a thermal power unit peak shaving cost model based on output fluctuations. Second, an optimized joint operation model is developed. Finally, the impact of changes in energy storage capacity and renewable energy output on the system peak shaving costs and energy storage lifespan is recorded. Simulation experiments are conducted based on actual operational parameters, and the results demonstrate that the participation of energy storage in deep peak shaving can indeed effectively reduce system peak shaving costs. Additionally, the actual operational lifespan of energy storage is significantly lower than the floating lifespan.