Integrated stochastic optimal self-scheduling for two-settlement electricity markets

Abstract

The complexity of current electricity wholesale markets and the increased volatility of electricity prices because of the intermittent nature of renewable generation make independent power producers (IPPs) face significant challenges to submit offers. This challenge increases for those owning traditional coal-fired thermal generators and renewable generation. In this paper, an integrated stochastic optimal strategy is proposed for an IPP using the self-scheduling approach through its participation in both day-ahead and realtime markets (i.e., two-settlement electricity markets) as a price taker. In the proposed approach, the IPP submits an offer for all periods to the day-aheadmarket for which amultistage stochastic programming setting is explored for providing real-time market offers for each period as a recourse. This strategy has the advantage of achieving overall maximum profits for both markets in the given operational time horizon. Such a strategy is theoretically proved to bemore profitable than alternative self-scheduling strategies as it takes advantage of the continuously realized scenario information of the renewable energy output and real-time prices over time. To improve computational efficiency, we explore polyhedral structures to derive strong valid inequalities, including convex hull descriptions for certain special cases, thus strengthening the formulation of our proposed model. Polynomial-time separation algorithms are then established for the derived exponentialsized inequalities to speed up the branch-and-cut process. Finally, both numerical and real case studies demonstrate the potential of the proposed strategy.