Considering the economic benefits of the combined wind-storage system and the promotion value of using energy storage to suppress wind power fluctuations, it is of great significance to study the optimal allocation of energy storage capacity for wind farms.
The goal of wind farm energy storage capacity optimization is to meet the constraints of smooth power fluctuations and minimize the total cost, including the cost of self-built energy storage, renting CES, energy transaction service, wind abandonment penalty and smooth power shortage penalty.
Wind farms can lease CES to suppress wind power fluctuations, which brings new problems of energy storage capacity configuration. Therefore, it is urgent to study the joint optimal configuration of leased CES capacity and self-built physical energy storage capacity.
Taking full account of the demand of wind farms to extend the service life of self-built energy storage and suppress wind power fluctuations, an optimization model of wind farm capacity configuration based on CES service is established. Through theoretical analysis and case studies, the following conclusions can be drawn:
Considering whole-life-cycle cost of the self-built energy storage, leasing and trading cost of the CES and penalty cost of wind abandonment and smooth power shortage, an optimal configuration model of combined energy storage capacity in wind farms based on CES service was established to minimize the total annual cost.
The CES operator can aggregate idle energy storage capacity and invest in a portion of centralized energy storage devices to provide energy storage leasing service. Wind farms can lease CES to suppress wind power fluctuations, which brings new problems of energy storage capacity configuration.