Design And Optimization Of A Stand-Alone Power System Based On Renewable Energy Sources

A stand-alone power system for small to medium scale applications requires the exploitation of renewable energy sources (RES), such as solar and wind energy, in conjunction with a hydrogen production and long-term storage system. Surplus energy is supplied to a PEM electrolyzer and the produced hydrogen is used in a PEM fuel cell to provide power in cases of energy deficit. In order to account for short-term needs, a lead-acid accumulator is employed and charged by the RES or the fuel cell depending on the availability of the RES and the accumulator State-of-Charge, SOC. Power management strategies that aim at the efficient operation of every subsystem are developed. Moreover, the current study presents a novel design approach that optimally determines the capacity requirements for all subsystems and further calculates the optimal operating conditions of the power management strategies. An optimization method in the form of simulated annealing is employed to identify the solution to the resulted large scale, discontinuous and discrete optimization problem.