Japan’s Organization for Cross-regional Coordination of Transmission Operators (OCCTO) has announced the results for the FY 2025 Long-Term Decarbonized Power Source Auction, selecting 28 winners, which included winners for 10 lithium-ion (Li-ion), nine for Li-ion, and two for pumped storage projects for a total energy storage capacity of 1.7 GW.

OCCTO awarded contracts for approximately 7.3 GW of future power capacity, including 4.26 GW of decarbonized energy sources. This included 551 MW of awarded capacity for Li-ion battery projects, 699 MW for non-Li-ion battery projects, and roughly 453 MW for pumped storage projects.

Battery Park 20 GK, CHC Japan, and CS Aomori Hachinohe ESS GK secured the three highest capacities for Li-ion battery projects. They won capacities of 114.01 MW, 112.35 MW, and 90.73 MW, respectively.

Battery Storage Station No. 3 GK, ZEUS GK, and Stonepeak Kingdom Holdings GK were the top three winners for non-Li-ion project capacities, securing 281.62 MW, 149.33 MW, and 141.51 MW, respectively.

TEPCO Renewable Power and Hokkaido Electric Power secured capacities of 267.55 MW and 185.9 MW, respectively, for pumped storage projects.

This March, OCCTO awarded 79 MW of solar capacity in the 27th solar power auction, the fourth auction held in fiscal year 2025, with a weighted-average winning price of ¥4.61 (~$0.029)/kWh.

In December 2025, OCCTO announced Japan’s 26^th solar power auction for projects of at least 250 kW, securing 75.4 MW from the original auctioned capacity of 163 MW.

In 2023, Japan announced the results of the 18th utility-scale solar photovoltaic projects auction, allocating 105 MW to 33 successful bidders.

In the same year, OCCTO concluded the 17th auction for 69.07 MW of grid-connected solar power projects, announcing 55 successful bidders. The total bid capacity in the auction was 110.89 MW.

The global energy transition continued to accelerate in 2025, with renewable energy accounting for 49% of total installed power capacity worldwide, according to a recent report by the International Renewable Energy Agency. Renewables accounted for 85.6% of all new power capacity additions during the year, underscoring their dominant role in electricity system expansion. A total of 692 GW capacity was added in 2025, representing a 15.5% year-over-year growth. This pushed total global renewable power capacity to approximately 5,149 GW by the end of the year.