Solar Power Helps Japan Handle Electricity Surge

As temperatures soared to record highs across Japan this summer and people scrambled to beat the heat, power companies turned to solar power to weather the surge in air conditioner usage. After the March 2011 earthquake and tsunami, which forced the shutdown of all nuclear power plants—most of which are still offline—Japan's Ministry of Economy, Trade and Industry had asked the country to conserve electricity during the hot summer months, Nikkei reported.

But thanks to the rise of solar power, the Japanese government has refrained from issuing requests since 2016, with Trade Minister Hiroshige Seko saying on July 24 that special energy-saving efforts were currently unnecessary.

Utilities usually release their summer power demand forecasts before hot weather arrives. In May, they predicted the hottest summer in a decade, but said they would likely have a 3% supply capacity over expected demand—the minimum reserve needed to ensure stable supplies.

A representative of Tokyo Electric Power Co. Holdings, or Tepco, said that during times of peak demand, the company can obtain nearly 10 million kilowatts of solar power, or about 20% of total power needed.  A substantial portion of this is provided by companies and households equipped with solar panels, which sell their surplus power to the utility. Before the 2011 earthquake and subsequent Fukushima Daiichi disaster, nearly 30% of Tepco's annual electricity output were nuclear-derived. Now, despite operating no nuclear plants and having suspended operation at two oil-fired power plants, the utility seems to be doing fine.

"It is safe to say that Tepco's strategy hinges on solar power," a company executive said. Declining electricity usage has also helped. Peak power demand in summer decreased by about 12% in the fiscal 2016 from fiscal 2010, due in part to changing public perceptions regarding energy and the rise of energy-saving appliances. Still, this summer, more than half of Japan's utilities have already recorded higher-than-expected demand.

Kansai Electric Power had thought it had enough capacity but came up short on July 17 and July 18, forcing it to take corrective measures in the form of "negawatt" transactions and power interchanges.