Leveraging Energy Storage Resources to Improve Combined Cycle Gas Turbines Operational Efficiency

Combined-cycle Gas Turbines (CCGT) are gaining traction in recent years due to lower natural gas prices, high flex-ibility, and high efficiency. Compared to single cycle gas turbines, the introduction of heat recover steam turbines significantly improves the CCGT efficiency, which also subjects CCGTs to non-convex and nonlinear cost curves. However, in widespread geographical power service territories with electricity markets, a Regional Transmission Organization (RTO) can only process piece-wise linear cost curves of generating resources due to the computational complexity. Therefore, the nonconvex cost curves of CCGTs are approximated by piecewise linear cost curves, which deviate from the actual cost curves and subsequently leads to inefficient dispatch of the CCGTs. This issue can potentially be addressed by co-locating energy storage resources with CCGTs. The energy storage is dispatched to maintain CCGTs operated at the economic output range. To this end, this paper proposes a computational model to optimize the coordination of energy storage resources and CCGTs such that the operational efficiency of CCGTs is improved.