OCCTO awarded 7.3GW (derated) across 32 projects in Japan’s third long-term decarbonization auction (LTDA), accounting for 67% of the 10.86GW bid, results released on May 13, 2026, show. The awards included 28 projects totaling 4.26GW in the decarbonization sources category and four totaling 3.04GW in the LNG-fired thermal plant category.
Unlike in the previous LTDA, in FY2025, storage projects with a duration of less than 6 hours were not eligible to participate and categorization by duration was abolished. Instead, they were split into a category including pumped hydro (PHES) repowering and lithium-ion batteries, and a category covering new PHES, non-lithium-ion batteries, and long-duration energy storage (LDES). Additionally, cell procurement and cybersecurity rules were tightened.
With the new restrictions, battery storage bid capacity more than halved from nearly 7GW in FY2024 to 2.73GW. Awarded capacity saw a modest decrease from 1.37GW to 1.25GW, including 551MW of lithium-ion and 700MW of other technologies. Combined, battery storage accounted for 29% of the total capacity awarded to decarbonization sources.
Two PHES projects, including the repowering of TEPCO Renewable Power’s Shiobara Power Station Unit 2 and the construction of a new unit at Hokkaido Electric Power’s Kyogoku Power Station, were also selected in the auction.
Nuclear power plants accounted for 46% of the total capacity awarded in the decarbonization sources category. Hokkaido Electric Power secured a contract for Tomari Nuclear Power Plant Unit 1 under a category for supporting upgrades required to meet post-Fukushima safety requirements. J-POWER did so for Oma Unit 1, currently under construction in Aomori Prefecture, marking the first time a new nuclear power plant secured an LTDA contract.
Pure hydrogen-firing thermal power plants were also awarded for the first time, one each to CEF H2 and Hoku Energy. Remaining awards in the decarbonization sources category included two ammonia co-firing retrofits of thermal plants and one biomass project.
The LNG category included four selected projects: JERA’s Sodegaura Power Station new Units 1 and 2, Hokuriku Electric Power’s Toyama Shinko Power Station LNG Unit 2, and Kyushu Electric Power’s Shin-Kokura Power Station Unit 6.
METI has already begun discussing potential changes to LTDA rules applicable from the next round, including a revision of restrictions around lithium-ion cell procurement.
