Grid-readiness signals
A reference map overlaying major transmission lines and substations around Kanto, Tohoku, Kansai, Hokkaido, Kyushu, Chugoku and Shikoku with the data centers published on this site. Proximity to a transmission line does not mean power can be supplied. Grid status, available capacity and lead times must be confirmed through official information published by the transmission and distribution operator for each area 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 sourceGrid status and available capacity
東北電力ネットワーク 系統の予想潮流等に関する情報
Accessed 2026-08-06
It provides grid constraint areas, projected power flow, available capacity, and guidance on grid access studies for lines and substations. It is published information calculated around generation interconnection and does not show whether a data center can receive power or contract capacity.
View the official sourceDemand and transmission/distribution information
東北電力ネットワーク 需要・送配電に関する情報
Accessed 2026-08-06
It publishes area-by-prefecture grid configuration, actual power flow for lines and transformers, facility plans, and medium-term congestion outlooks for the 2030 fiscal-year scenarios.
View the official sourceDistribution facility construction plan
東北電力ネットワーク 流通設備建設計画
Accessed 2026-08-06
It provides transmission and distribution facility construction and reinforcement plans. The existence of a plan alone does not establish connection feasibility or an operating date for the Akita AI data center.
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 sourceDemand-side supply capacity
HELLO NEW HOKKAIDO でんきとつながる地図
Supply capacity as of 2025-12, grid diagram as of 2026-05
An official map for extra-high-voltage customers that overlays indicative supply capacity with industrial land information. The capacity figures are simplified estimates, and individual prior consultation is required.
View the official sourceGrid configuration and congestion
ほくでんネットワーク 系統情報の公表について
Preliminary congestion data for 2026-06
Projected power flow, distribution facility construction plans, and the congestion map (formerly the available-capacity map, for systems of 187 kV and above). 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 sourceDemand-side supply capacity
九州電力送配電 ウェルカムゾーンマップ
Available capacity on the area pages as of 2026-03
For customers considering siting a facility, it lists per area the grid substations with 50,000 kW or more of available capacity, alongside industrial land information. The figures are approximate and individual prior consultation is required.
View the official sourceGrid configuration and available capacity
九州電力送配電 系統情報の公開
Updated 2026-06-26
Projected power flow and available capacity per transmission line, the medium- to long-term outlook for grid congestion, and equipment investment and retirement plans. 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 sourceDemand-side supply capacity
中国電力ネットワーク ウェルカムゾーンマップ
No update date is stated on the page (it notes that available capacity changes with applications)
A demand-side page bringing together the main industrial sites in the Chugoku region, the supply capacity map, and guidance on phased supply matched to expansion plans. The figures are indicative and individual consultation is required.
View the official sourceGrid configuration and available capacity
中国電力ネットワーク 系統アクセス情報の公開
Information on projected power flow and related data updated 2026-07-27
Projected power flow and available capacity, transmission and substation development plans, and information on battery storage interconnection. 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 sourceDemand-side supply capacity
四国電力送配電 ウェルカムゾーンマップ
As of 2026-07-22
For customers seeking extra-high-voltage supply, it publishes the available capacity of substations and transmission lines by prefecture. The operator explicitly states that this map is not intended for power generators. The published values are indicative and detailed study is required.
View the official sourceGrid configuration and available capacity
四国電力送配電 系統アクセスに関するデータ集
No update date is stated on the page
Publishes grid configuration, projected power flow and available capacity by prefecture for the trunk system (187 kV and above) and local systems. 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. HVDC links (Hokkaido-Honshu, Hida-Shinano, Kii Channel) are drawn as dashed lines to distinguish them from AC.
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 official information for assessing supply feasibility (TEPCO Power Grid, WELCOME ZONE MAP; Tohoku Electric Power Network, projected power flow and available capacity information; Kansai Transmission and Distribution, Welcome Zone Map; HELLO NEW HOKKAIDO, map of grid connections and industrial land; Kyushu Electric Power Transmission and Distribution, Welcome Zone Map; Chugoku Electric Power Transmission & Distribution, Welcome Zone Map; Shikoku Electric Power Transmission & Distribution, Welcome Zone Map), 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. AC and DC are told apart solely by the OpenStreetMap frequency tag (DC = 0); elements without that tag are not asserted to be AC and are drawn like AC, while the GeoJSON keeps the distinction as current_type=unknown. 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.