Coupling fuel-constrained power plant and NaS battery system for profit increment in a competitive electricity market

This work introduces coupling fuel-constrained power plant and electric energy storage plant aim to overall profit increment in a restructured electricity market. Among electric energy storage technologies, we select NaS battery (Natrium Sulfur battery) systems for coupling with power plant because of their enough technological maturation and less environmental impacts. The goal is investigating the coupling efficiency on profit increment considering various intensities of power plant's fuel constraint. In order to reach this goal, the amount of overall profits of fuel-constrained power plant, NaS battery plant and their coupling are first calculated in a specific time interval. Then, the coupling efficiency is determined using incremental profit rate. Having an appropriate strategy to calculate this parameter is essential. Hence, a comprehensive approach to self-schedule of individual and coupled plants is developed. This comprehensive self-scheduling approach is therefore formulated and solved as a mixed integer non-linear programming (MINLP) problem. Numerical results for a case study are discussed.