Effects of dispatch strategies on optimum sizing of solar-diesel-battery energy storage-RO desalination hybrid scheme by efficient heuristic algorithm

Abstract

Dispatch strategies on optimum sizing of hybrid renewable energy systems are crucial for attaining a cost-effective and reliable power supply. In this paper, the effects of dispatch strategies on optimum sizing of photovoltaic/energy storage/diesel/ reverse osmosis desalination hybrid scheme for supplying the electrical loads and freshwater demand of a remote region are presented. The size of the components of the hybrid scheme are optimized to minimize the total net annual cost and minimizing the system's Levelized cost of energy and to minimize the cost of the desalinated water produced, and the reliability index. For this aim, two optimal dispatch strategies, load following, and cycle charging, are designed for integrated energy systems. So an efficient heuristic algorithm, tabu search, is used for optimum sizing of the hybrid energy scheme. The results are compared with the results obtained by well-known optimization method, harmony search. In each of the strategies, the effects of reliability index and economic factors, including diesel generator initial cost, fuel cost, the O&M cost of diesel generator, initial battery cost, photovoltaic initial cost, and the interest rate, on the optimization of the hybrid energy scheme have been investigated. It showed that the tabu search algorithm has potential benefit to reduce total cost by nearly 1.8% and average simulation time by nearly 1.65% as compared to the harmony search algorithm. Also, in a specific reliability index, the cycle charging strategy has potential benefit to reduce greenhouse gas emissions by nearly 11.5% per year and the cost criteria by nearly 7.5% as compared to the load following strategy.