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PUMPING UP THE VOLTAGE:
The experimental facility in Okinawa could be a sign of power plants to come. (Photo: Electric Power Development Co.)
The world's first experimental power station that uses sea water pumped to and released from a height is being built in the north of the island of Okinawa. The brine is raised during the night, when electricity-consumption rates are low, and released from a storage reservoir on high land to generate power during the day, when consumption rises. If the trial plant is successful, it is hoped that Japan, with its long coastline, will be able to more easily solve its problems of finding sites for power generation.
The Inexhaustible Sea
At Kunigami, water is lifted by pump to a reservoir 150 meters above sea level and released en masse to generate electricity at an underground facility before being returned to the sea. Power can be supplied when needed at any time after the preliminary pumping work is complete. Maximum capacity is 30,000 kilowatts for six hours, enough to supply households accounting for 30,000 people.
If it turns out to be feasible to use the inexhaustible resources of the sea in this way to generate power, it will be possible to consider far more locations for power stations in Japan. But there are many technical hurdles, including impregnation of turbines and other generation equipment against sea water corrosion, and stopping saline damage to the surrounding environment. Designers have come up with solutions such as using strong fiberglass-reinforced plastic for the conduits that direct water to the turbines and making the turbines themselves of special stainless steel.
The Need for New Power Sources
The coming age of information technology is expected to place an even greater burden on power resources and further stretch the bounds of fluctuation in demand. Thus the importance of this new power-generation technology will gradually grow. The greater the distance between the reservoir and the underground generator, the greater the amount of power that can be generated. For this reason, the best locations for this kind of facility are those that take advantage of cliffs and other rugged coastal terrains. If this trial is successful, places near Tokyo, such as Izu, could become candidate sites for power generation. This would raise the prospect of reduced power-distribution costs, since facilities would be close to an area of concentrated demand.
Edited by Japan Echo Inc. based on domestic Japanese news sources. Articles presented here are offered for reference purposes and do not necessarily represent the policy or views of the Japanese Government.