Grid-readiness signals
A reference map overlaying major transmission lines and substations around Kanto and Kansai with the data centers published on this site. Proximity to a transmission line does not mean power can be supplied. Available capacity and lead times must be confirmed through the demand-side information published by the transmission and distribution operator for each area (TEPCO Power Grid, Incorporated and Kansai Transmission and Distribution, Inc.) and through individual prior consultation.
Switch areas, then select a line or point to see its voltage class and the underlying OpenStreetMap element.
Demand-side supply capacity
東京電力パワーグリッド WELCOME ZONE MAP
As of 2025-12
For extra-high-voltage customers. Available capacity and indicative lead times change, and individual prior consultation is required.
View the official sourceGrid configuration and projected power flow
東京電力パワーグリッド 系統情報
Updated 2026-07-16
Grid configuration, projected power flow, investment and retirement plans, with CSV. Generation-side available capacity is not treated as data center supply headroom.
View the official sourcePolicy background
資源エネルギー庁 局地的大規模需要への対応
2025-01
A policy document on steering data centers and similar loads toward locations that can be supplied early, and on planned grid development.
View the official sourceDemand-side supply capacity
関西電力送配電 ウェルカムゾーンマップ
Updated 2026-07-16
For high-voltage and extra-high-voltage customers. Available capacity and indicative lead times change, and individual prior consultation is required.
View the official sourceGrid configuration and available capacity
関西電力送配電 流通設備建設計画・系統連系制約等
Updated 2026-06-18
Construction plans for distribution facilities, available-capacity mapping and more. Generation-side available capacity is not treated as data center supply headroom.
View the official sourceNationwide available-capacity maps
資源エネルギー庁 各一般送配電事業者の空き容量マップ
Reference portal
An official link collection to the available-capacity maps published by the transmission and distribution operators of all 10 areas in Japan.
View the official sourceShows
Transmission lines and substations of 154 kV and above registered in OpenStreetMap, and their approximate positional relationship to published data centers.
Does not show
Contractable power, current available capacity, whether connection is possible, construction costs, supply start dates, or redundant supply routes.
How to confirm
Check the demand-side WELCOME ZONE MAP (TEPCO Power Grid) and Welcome Zone Map (Kansai Transmission and Distribution), and ultimately carry out prior consultation and a connection study with the relevant transmission and distribution operator.
The physical network is derived from data © OpenStreetMap contributors under the Open Data Commons Open Database License (ODbL), extracted per area, filtered by voltage class and converted to GeoJSON (the retrieval date is shown at the top right of the map). Because it depends on what has been registered, completeness and current status of equipment are not guaranteed. Images from the operators' welcome-zone pages are not reproduced; only links to the official pages are provided.
For the overall picture of electricity demand see Energy, and for per-facility sources and coordinate precision see Facilities.