Electricity saving targets came into effect in Japan on Monday as the country eyes a power shortfall over the hot summer, despite the weekend re-start of a nuclear reactor, AFP reports.
The government has asked households and businesses served by six utilities in central and western Japan to voluntarily cut consumption of electricity by between five and 15 percent on summer 2010 levels through to September 7.
Power consumption usually rises in the summer as people turn on air conditioners to cope with the sometimes sweltering weather.
A seven-percent reduction target will also come into force in Japan's northernmost -- and more temperate -- island of Hokkaido on July 23.
The campaign took on greater urgency on Monday when Kansai Electric Power, whose service area is being asked to cut useage by 15 percent, said they had suspended operation at a thermal power plant in Himeji, western Japan, because of a steam leakage.
News reports said it would take about 10 days before power generation at the plant could be brought back online, with the outage expected to raise estimated power demand in the region from 81 percent of capacity to 86 percent.
The reductions are voluntary and there is no penalty for individual consumers and businesses that do not meet them, but the government has said it will order rolling blackouts if demand reaches 99 percent of supply.
The targets come as Japan ended almost two months without any functioning nuclear reactors, with the restart Sunday of Unit No. 3 at Oi nuclear power plant.
Japan had been operating without nuclear power since early May when the last of its 50 working reactors was shut down for a scheduled safety check.
Restarts had put been on hold as the government mulled its options following a 9.0-magnitude earthquake and tsunami that crippled reactor cooling systems at Fukushima, amid predictions that more giant quakes would strike Japan.
But on June 16, Prime Minister Yoshihiko Noda gave the green light to restart two reactors at the Oi plant amid warnings the industrial heartland of western Japan could be as much as a fifth short of electricity.
Prior to the disaster at Fukushima, nuclear power had supplied a third of Japan's electricity needs.