Optimal multi-market operation of gravity energy storage and wind power producer using a hybrid stochastic/robust optimization

Abstract

In light of physical limitations, the well-known large-scale pump hydro energy storage was unable to take place in predominantly flat areas. The utilization of innovative gravity energy storage (GES) has increased in the power system in the past few years, with no geographical restrictions and reduced investment costs. According to the paucity of installed GES, a proper formulation considering the physical specifications of gravity energy for market participants in GES has not been sufficiently investigated. In this paper, a new non-linear formulation for the strategic multi-market running of GES and wind suppliers in an uncertain environment characterized by joint robust optimization (RO) and stochastic programming is introduced. Using piecewise linearization, the proposed nonlinear model is then reformulated as a linear version. In the proposed method for market involvement, the bid-offer plans of the GES are obtained in order to participate actively in the DA market. Obtained results show that market conditions significantly impact the profitability of the system, with a 30 % reduction in the day-ahead (DA) price leading to a 32 % reduction in daily profit. Also the risk-based operation of the GES and wind producer is compared with risk-neutral condition, highlighting the importance of considering intraday and real-time markets and risk profiles in optimizing the operation and profitability of the hybrid wind-GES system.