Tokyo is a top-five global hub and nuclear restarts are easing supply, but power is among the most expensive anywhere and island-grid access is constrained.
See live grid data →Constrained island-grid access (OCCTO).
Improving availability as nuclear restarts (15 reactors back, ~33 GW).
Very high cost.
High momentum (Tokyo).
Carbon moderate-high (~450 g), LNG/coal.
National roll-up of the east-west split: the 50Hz east issued Japan's first power shortage warnings in 2022 and stays structurally tight with only ~1.2 GW of frequency-converter links (rising toward 3 GW by 2027) to the western surplus; the 60Hz west is comfortable. Tokyo-bound load carries the eastern risk; see JP-E / JP-W.
What this means: A large new load faces occasional exposure here. Monitor conditions and keep a contingency plan.
event-based · Tokyo first-ever power shortage warning 2022 (Nippon.com) · Japan east-west converter capacity (Wikipedia)
We have not compiled what firm service actually promises here: whether it is firm, non-firm or interruptible, the conditions under which you can be curtailed, the redundancy required of you, and the transfer time behind any N-1 commitment. Treat this as an open diligence item, not as an indication that service is firm.
Utility feeds, UPS, storage, on-site generation, islanding, black start and the residual energy you still expect to lose are properties of a specific site design, not of a market. This layer only exists once there is a site, and we never assert it for you.
Limited
0 of 1 data layers measured
Partial
1 of 3 dimensions: reliability, connection, cost
June 2026
per-layer vintages below
| Layer | Method | Vintage | Freshness | Source |
|---|---|---|---|---|
| PGIQ Rating opinion | opinion | June 2026 | Current | PGIQ methodology |
| Reliability review | assessed | 2025 | Fresh | Tokyo first-ever power shortage warning 2022 (Nippon.com) |
Freshness reflects each layer's refresh cadence: reliability annual to three-yearly, capacity-auction and queue yearly, tariffs every year or two. The full cross-market freshness dashboard is at /data-quality.
How Japan's reliability-adjusted score and tier have moved, month by month. Part of your Analyst Desk.
This page is our full read on Japan alone, and it is free. To decide where a large load should actually go, you need every market side by side, ranked on recurring cost and time-to-connect, with the history and alerts when your shortlist moves. That is the Analyst Desk.
With your Analyst Desk, compare Japan against every market side by side, ranked on recurring cost and time-to-connect, with the full history and shortlist alerts.