Electricity supplies in the quake-hit Tohoku region came close to failing on Aug. 5, with demand reaching 97.7 percent of supply capacity at one point in the afternoon. Record rainfalls in late July forced the suspension of 29 hydroelectric power plants along the border of Niigata and Fukushima prefectures, cutting Tohoku Electric Power Co.'s capacity by about a gigawatt. Fierce temperatures on Aug. 5 pushed that reduced capacity to the limit.
Electricity supplies in the quake-hit Tohoku region came close to failing on Aug. 5, with demand reaching 97.7 percent of supply capacity at one point in the afternoon.
Record rainfalls in late July forced the suspension of 29 hydroelectric power plants along the border of Niigata and Fukushima prefectures, cutting Tohoku Electric Power Co.'s capacity by about a gigawatt. Fierce temperatures on Aug. 5 pushed that reduced capacity to the limit.
With the mercury rising to 35.6 degrees in Akita city and 34.1 degrees in Niigata city, demand for air conditioning rose sharply.
Power use peaked at 11.83 gigawatts at 2:30 p.m., with maximum supply capacity standing at 12.11 gigawatts. Tokyo Electric Power Co. (TEPCO) began supplying Tohoku Electric with 0.3 gigawatts of power on Aug. 4, saving the region from blackouts.
Tohoku Electric is expected to continue to have to rely on supplies from other regions to prevent shortages through next week. Aomori, Iwate, Akita, Miyagi, Yamagata, Fukushima and Niigata prefectures are all supplied by the company.
Officials are focusing on quickly repairing the flood and other damage to power stations caused by the rains and are calling on customers to make further power-saving efforts in the meantime.
Tohoku Electric is entitled to receive up to 1.4 gigawatts in power supply from TEPCO. Supply capacity on Aug. 5 would have been 11.7 percent higher than demand if that external supply had been drawn on.
But TEPCO may not be able to supply enough power to Tohoku Electric if the supply-demand situation tightens in its own region.
Meanwhile, the Ministry of Economy, Trade and Industry is preparing to relax the restriction order on the use of electricity in the three prefectures hit hardest by the Great East Japan Earthquake--Iwate, Miyagi and Fukushima prefectures. All of the prefectures are served by Tohoku Electric.
The central government is committed to issuing warnings of rolling blackouts whenever supply margins are projected to fall below 3 percent, but the Agency for Natural Resources and Energy said it was not currently necessary to issue such a warning in Tohoku.