Tokyo Electric Power Co. (TEPCO) shut down its 900-MW Shiobara pumped-storage project January 29 to repair leaks in its dam.
TEPCO said it decided to shut Shiobara, on the Kosabi River in eastern Japan, after discovering the problem when the company checked through data that had been falsified in the past.
A company spokesman did not know how long the shutdown would last. However, the utility, which powers Tokyo and nearby eastern areas, said it would not be required to increase the operation of its thermal power plants in the meantime.
TEPCO said winter demand is not as strong as in peak summer and the hydropower plant accounts for about 1.4 percent of its total generating capacity. The spokesman also said demand has been soft due to a mild winter.