New figures from Japan's Ministry of Economy, Trade and Industry (METI) show that wind and solar power curtailment increased significantly to 1.76 TWh over the past 12 months, from 0.57 TWh in fiscal 2022 and 0.53 TWh in fiscal 2023.
Renewable energy curtailment soared in Japan in fiscal 2023, which spans from April 2023 to March 2024.
According to Japan's Renewable Energy Institute, which relies on data provided by METI, solar and wind energy curtailment grew from approximately 0.10 TWh in fiscal 2018 to around 1.76 TWh in the last fiscal year.
“This value is more than double those in Australia and California,” the research institute said.
Renewable energy curtailment reached 0.57 TWh in fiscal 2022 and 0.53 TWh in fiscal 2021. In the preceding two years, curtailment hit 0.40 TWh and 0.46 TWh.
“Until fiscal year 2021 curtailment was limited to Kyushu,” said the Renewable Energy Institute. “Except for Tokyo, curtailment is now affecting all the power systems of the country. The situation has become particularly problematic in Kyushu where the curtailment rate of solar and wind power was projected to reach nearly 7% in fiscal year 2023.”
The institute said that PV systems with a capacity of up to 10 kW are not exposed to curtailment and noted that “curtailment is essentially solar curtailment.” It added that power generation from PV sources is concentrated during the daytime and in spring, “when solar irradiance conditions are good and electricity consumption is the lowest.”
The institute suggested economic dispatch and negative prices as an antidote to reduce curtailment in the coming years.
According to the International Renewable Energy Agency (IRENA), Japan reached a cumulative installed PV capacity of 87.0 GW at the end of 2023. Last year, the country deployed around 4 GW of new solar capacity.