Abstract
Though Photovoltaic power generation (PV) and wind power generation (WG) have advantages that energy are clean and infinite, they have a disadvantage that electrical output energy are unstable. The disadvantage causes them to need big energy storage device such as a battery and to increase their construction cost. A PV/WG hybrid system is effective for stabilizing output in specific locations that yearly profile of solar energy is different from that of wind energy. However, as the stability has a relation to a ratio of PV output energy fluctuation to WG output energy fluctuation, it is very important to clear the optimum ratio. The optimum ratio from the point of view of long-term stability for the output energy was cleared by simple simulations. And it was cleared that the optimum ratio changes from approx. 20 to 75% according to environment and that optimizing the ratio can reduce the battery capacity very much.
