Meanwhile, Table 1 shows the water discharge amount discharged from Amagase Dam from 19:00 to 19:01 on June 21, 2011 (total water discharge amount, information distributed on the internet of Ministry of Land, Infrastructure, Transport and Tourism). Before the rainy season in Japan, unless water is discharged from Amagase Dam, there is a risk of burst of the dam and collapse of the house caused by flood and landslide, for example. From Table 1, the water discharge amount per 1 second of the above described period is 82.8 tons. The water discharge amount per 1 month calculated from the above data is 214,617,600 tons (82.8 tons × 60 seconds × 60 minutes × 24 hours × 30 days). It is a waste to leave such a large amount of water continuously flow. Therefore, such a large amount of water can be used efficiently by using the power generation method of the present invention. Although anti-nuclear power plant is acknowledged as a problem today, the inventor of the present invention considers that the problem can be solved by efficiently using that. In general, it is said that it is technologically impossible to store electricity (alternate current) used in a home currently on the earth. However, the impossibility is turned to possibility by using the power generation method of the present invention. In other words, by using the power generation method of the present invention, the potential energy can be permanently and unlimitedly stored and power can be generated immediately at any time. Here, “permanently and unlimitedly” means that rain is made to fall by energy radiated from the sun and the potential energy of the water trapped at the high place by the rain can be converted into the potential energy of the weight WT and stored.
