Le blog de fukushima-is-still-news

September 3, 2015

Solar power proved its worth this summer

http://ajw.asahi.com/article/behind_news/social_affairs/AJ201509030045

By DAISUKE HIRABAYASHI/ Staff Writer

Solar power accounted for 10 percent of the nation’s electricity when demand peaked this summer, showing that alternative energy is a key resource in times of need.

A survey by The Asahi Shimbun found that Kyushu Electric Power Co. covered 24.6 percent of all its electricity needs, or 3.65 gigawatts, with solar facilities from 12 p.m. to 1 p.m. on Aug. 6, when the company said power demand peaked in areas it serves.

The newspaper asked all major regional power companies what day power demand peaked in areas they serve between July and August, the maximum hourly solar output on that day and the time their solar plants recorded peak outputs.

Valid responses were received from all utilities except Okinawa Electric Power Co.

All nine responding utilities said their highest demand was recorded in early August, and that their solar output peaked between 11 a.m. and 2 p.m.

The reported maximum hourly outputs of the utilities’ solar plants totaled 15 gigawatts--equivalent to the amount of energy produced at around a dozen nuclear reactors in an hour.

The amount of electricity needed across the country during the hours the companies' solar plants were generating maximum output was estimated at 150 gigawatts.

That means solar power covered 10 percent of all electricity needs during the hottest days of August.

The survey also showed that solar power generation accounted for around 16 percent and 12 percent of all power needs for Shikoku Electric Power Co. and Chugoku Electric Power Co., respectively, on their days of peak consumption.

The nine companies’ ratios of solar power varied, depending on whether their plants received sufficient sunlight and the size of the facilities.

All of the nation's nuclear reactors remained offline until recently due to the nuclear disaster in Fukushima Prefecture that was set off by the March 2011 earthquake and tsunami.

Because of this, utilities have tried to avert power shortages by operating oil thermal power plants, which emit huge amounts of carbon dioxide.

Solar power accounted for just 2 percent of all power generation on an annually adjusted basis.

Even so, the study showed that clean energy was useful during the dog days of August and helped reduce greenhouse gas emissions.

Kyushu Electric and Chubu Electric Power Co., however, pointed out that solar power is not 100-percent reliable because “unexpected changes in the weather make it difficult for utilities to correctly estimate solar plants’ outputs.”

Photovoltaic stations with a total output of 2.84 gigawatts had been introduced as of the end of fiscal 2009. The figure surged to 27 gigawatts by the end of fiscal 2014, due largely to the government feed-in tariff system for clean energy.