Extreme Heat Stretches Japan’s Power Grid to Near Its Limits

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(Bloomberg) — Japan is asking Tokyo residents to conserve power, with unusually hot weather stretching the city’s grid close to its limits as fears grow that the heat could last for longer.

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Electricity supply in the capital was set to be “very tight” in the afternoon, the Trade Ministry said on Sunday. Businesses have responded to the requests, with convenience operator Seven & i Holdings Co. saying it would shift when stores prepare food items while electronic store operator Yamada Holdings Co. said it will turn off four-fifths of display televisions, lights and cooling units unless customers request they be switched on.Temperatures will be as high as 35 degrees Celsius (95 Fahrenheit), according to the country’s meteorological agency, way above the 30-year average of 22.5 Celsius.  The rainy season in the greater Tokyo area ended the earliest on record going back to 1951, pointing to longer and hotter periods that’ll pressure the grid.

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The government and utility providers have repeatedly warned that electricity supply will be constricted this summer, and have encouraged people to conserve power, including by offering rewards to people to cut back on their usage. The Tokyo area isn’t unique in Asia in seeing demand surge because of unusual heat, with consumption hitting peaks in key regions in northern China and Taiwan.Read more: Global Energy Shortage Sets Stage for a Hot and Deadly SummerJapan in March issued a power supply warning, the first of its kind, after supply neared critical levels in Tokyo and has since introduced a new system to warn people to prepare for potential crunches. Meanwhile, the heat wave is pushing up the national spot power price, with electricity for next-day delivery surging to 41.7 yen ($3.09) a kilowatt-hour, the highest since March and near a record for the time of year.

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Tokyo residents are being asked Monday to turn off lights in rooms they are not using and to use air conditioning units in an appropriate way. The government will increase generation from thermal plants and ordered power sharing across Japan’s regions to tackle the crunch in Tokyo, it said. The period around 4:30 p.m. is crucial because solar power generation begins to decline as the sun goes down.Read more: Japan Power Crisis Was a Decade in Making and Won’t Go Away The measures appear to have had some success. The power reserve ratio, which measures the spare capacity of electricity, is slated to drop as low as 3% for the Tokyo area around 5 p.m., the minimum level considered necessary for stability on the power grid. It had earlier been seen below 1%. 

(Updates with power prices in fourth paragraph)