Battery storage market trends
How fast Japan's grid-scale battery fleet is growing, and whether projects are going where the price spreads are. Free to use; totals only.
Capacity by COD year
Actual operation year for operating projects, expected year for the rest. 281 of 445 published projects have a year.OperatingConstructionPlanned
2015’152016’162017’172018’182019’192020’202021’212022’222023’232024’242025’252026’262027’272028’282029’292030’30
2026 (this year) · 103 projects · 256 MWOperating 134 MW (51)Construction 18 MW (9)Planned 105 MW (43)MW reported for 102 of 103 projects
Pipeline against price spreads, by grid area
Disclosed MW of all published projects in each area, beside the average daily JEPX spot spread from 2025-11-13 to 2026-11-12.Hokkaido and Tohoku had the widest 2 h spreads (17.2 / 16.9 JPY/kWh) and hold 32% of the disclosed pipeline.
OperatingConstructionPlannedGrid areaPipeline (MW)Avg. 2 h spread (JPY/kWh)Avg. 2 h spread (JPY/kWh)
Hokkaido(33)87017.2
Tohoku(39)76616.9
Tokyo(99)67414.4
Chubu(59)30614.3
Hokuriku(6)10813.6
Kansai(41)59113.6
Chugoku(40)34413.8
Shikoku(6)2214.0
Kyushu(94)91114.5
Okinawa(2)22Not in JEPX
Area not yet known(26)439
How these figures are built
- Totals count every published project in the registry. MW adds up only the projects that report it, so it is a lower bound.
- A day's spread is the average of its 4 (2 h) or 8 (4 h) priciest half-hours minus as many of its cheapest on the JEPX day-ahead (spot) market: the headroom a battery could capture before losses, fees and grid charges. Okinawa is not part of JEPX.