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Gov't calls for energy savings this summer

 June 30, 2014

Calls for energy savings as Japan braces for first summer with no running nuke plants



The Japanese government is calling for energy savings to begin from July 1, as the nation faces its first summer since the 2011 Fukushima disaster with no running nuclear plants.

Particularly in regions under the jurisdiction of the Kansai Electric Power Co. and Kyushu Electric Power Co., which both relied heavily on nuclear power prior to the disaster, there is the possibility of energy supplies becoming stretched. Still, the government has, like last year, avoided setting numerical goals.

The energy-saving period covers the time frame from 9 a.m. to 8 p.m. for the whole of the country except for Okinawa Prefecture and runs until Sept. 30, excluding weekends and the period from Aug. 13 through Aug. 15. The government is calling for simple energy reduction measures like setting air conditioners to 28 degrees Celsius or higher.

This summer will be the fourth one in a row where the government is calling for energy saving efforts. The three summers so far have passed without major incident, and with the government pushing a policy of restarting the country's nuclear reactors, this summer's energy performance will come under scrutiny.

According to government estimates put together in April, the highest potential energy demand this August will be about 166.66 million kilowatts, while the highest potential energy supply will be about 174.34 million kilowatts, which would give a safety margin of around 4.6 percent, higher than the minimum desired margin of 3 percent.

However, while the August safety margin for eastern Japan is estimated at 6.1 percent, it is only 3.4 percent for western Japan, and that would be after borrowing power from the east. In September last year, the No. 3 and No. 4 reactors at Kansai Electric's Oi Nuclear Power Plant in Fukui Prefecture were shut down for inspection and remain offline, which has created the tight situation in western Japan.

Some 80 percent of the power supply this summer will come from thermal power plants. Around 20 percent of these thermal plants have been in operation for 40 years or longer, so they carry the risk of malfunction. Furthermore, according to the Japan Meteorological Agency, there is a possibility that a powerful high-pressure zone over the Pacific Ocean will cause higher than average temperatures in western Japan in August. Both equipment failures and extreme temperatures could potentially cause power shortages.

In its estimates for this summer, the government assumed a severe scenario with hot temperatures like in 2010 -- or 2013 for the regions supplied by Chubu, Kansai and Kyushu Electric Power -- and low generation from solar and hydroelectric sources. The government began creating such estimates in the summer of 2011 after the Fukushima nuclear plant disaster, and so far most of the estimates of power supply margins have ended up lower than what actually occurred.

The minimum power supply margin of 3 percent is to protect against momentary rises in demand that are estimated to go as high as 3 percent. During extremely high temperatures, margins of 7 to 8 percent are desired. When the margin is expected to fall beneath 3 percent, calls for power savings are issued and power companies borrow power from each other. When the margin falls within 1 percent, rolling blackouts are initiated.

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