Japan makes developers prove site rights as its battery queue reaches 172 GW
Serguey Asael Shinder2 min readJapan's grid coordinator has added a third rule this year to stop speculative projects from holding grid capacity, pv magazine reports. From 1 October, projects that receive grid connection approval must submit documents proving their right to use the project site within two months, or lose their reservation, under updated guidance from the Organization for Cross-regional Coordination of Transmission Operators (OCCTO).
The rule applies to contract applications received from 1 October and covers all generation projects except those under Japan's feed-in tariff and feed-in premium schemes. Upgrades at existing sites are exempt where they do not raise output or otherwise affect the grid, and transmission operators can extend the deadline where there are reasonable grounds. It was developed by a working group of the Ministry of Economy, Trade and Industry, which said the aim is to stop low-certainty projects from holding reservations so viable ones can connect faster.
The numbers explain the urgency. According to ministry figures, at the end of December 2025 about 172 GW of grid-scale battery capacity was at the connection-study stage and about 30 GW at the contract-application stage, against about 0.64 GW actually connected. At the end of September 2024 the figures were about 88 GW and 6.2 GW.
Two earlier measures already target batteries. Since 1 August each transmission operator caps the number of grid-scale battery connection studies one company can request in its area, after the working group found several companies had filed more than 100 requests with one operator in a short time; caps range from five in Hokkaido, Hokuriku, Chugoku and Shikoku to 12 in Kansai and 11 in the Tokyo area. Since June, battery projects must file their generation-side and demand-side applications together, because filing them separately let other applications land in between and changed the assumptions behind a project's grid study.
Why it matters
A queue three hundred times larger than what is connected is not a pipeline, it is a reservation system being gamed. Site-rights proof is a cheap filter, but the volume suggests the real constraint in Japan is not interest in storage but the speed of grid studies.