Optimized and Coordinated Operation of Mixed-Energy Power Sources in Electricity Market

This paper proposes an optimized operation scheme for a mixed-energy power plant consisting of renewable energy resources (RES), synchronous generators (SG), and energy storage systems (ESS). While the proposed method is applicable for any type of RES, SG, and ESS, a combination of RES, gas-fired generators, and battery energy storage system (BESS) has been utilized for the sake of simulation in this paper. Assuming that the total as well as RES generation are both forecasted and available within a known period of time, the difference between the two needs to be shared among gas turbine generators and battery storage units. To ease the computational burden, several gas turbine generators are aggregated to form a bulk synchronous generation unit. Considering constraints of SG and BESS, the objective of the optimization problem is to minimize gas turbine generation over the period of a day. After the share of the bulk SG and each battery energy storage unit is found, a unit commitment study for individual gas turbine generators is performed. The results found by this approach has proven to result in less overall schedule deviation compared to when BESS units are simply charged when demand is low and discharged when demand is high (up to their maximum capacity). In addition, this method entails low computation requirements and produces solutions in a short time.