Japan’s Okinawa prefecture curtails solar generation for first time

Okinawa Electric Power Co. has curtailed electricity supplied by solar plants and other renewables for the first time. The Japanese utility said it was forced to apply the measures in response to high solar radiation levels and low energy demand during the holiday period.

The control period will span from 8 am (GMT+9) to 4 pm and will be applied for at least three days, depending on the weather and demand conditions, the company said. It noted that the measure was applied from Jan. 1, when electricity demand reached approximately 669 MW against 738 MW of supply.

Okinawa is Japan's southernmost prefecture of Japan. According to the the Okinawa Times, the prefecture currently hosts around 1,400 solar installations.

Japan's Ministry of Economy, Trade and Industry (METI) issued its first “Power Crunch Alert” for the Tokyo Region in March, after an earthquake hit the region. In June, Mitsubishi and Japanese utility Kyushu Electric Power Co. said they would team up to use grid-scale battery storage to reduce the impact of solar curtailment on the island of Kyushu, in southern Japan.

According to Japan's Institute for Sustainable Energy Policies (ISEP), the island of Kyushu had around 10.5 GW of PV and 600 MW of wind capacity installed under the country's feed-in scheme by the end of 2021. The curtailment rate in the region for the entire year was estimated at around 4.4%, up from 3.8% in the preceding year.