Multiobjective Optimal Unit Sizing of Hybrid Power Generation Systems Utilizing Photovoltaic and Wind Energy

A deterministic approach to optimal unit sizing is presented for hybrid power generation systems utilizing photovoltaic and wind energy. Device capacities and electric contract demand are determined so as to minimize the annual total cost and annual energy consumption from the viewpoints of economy and energy saving or reduction in NO_x and CO₂ emission, respectively. This optimization problem is considered as a multiobjective one, and a discrete set of Pareto optimal solutions is derived numerically by using the weighting method. Two systems interconnected with the electric power grid are investigated: one has the option of reverse electricity flow into the grid, and the other has no option. By carrying out some case studies, the tradeoff relationships between the two objectives as well as the optimal values of device capacities are clarified. The influence of electricity deficit on unit sizing is also investigated.