Japan's Data Centre Boom Is Arriving Later, and Into a Tighter Fuel Market

Japan's electricity planners have two problems that are starting to overlap. The first is forecasting how much power new data centres will need and when. The second is securing the fuel to supply it, after the Strait of Hormuz disruption pushed up the price of liquefied natural gas (LNG) across Asia. In August 2026, OCCTO, Japan's cross-regional grid coordinator, published its aggregation of electricity supply plans for fiscal year 2026, and both problems were visible in its findings.

OCCTO said it is becoming increasingly difficult to forecast highly probable demand, mainly because data centres keep postponing the start of operation. OCCTO's 10-year demand outlook, published on 21 January 2026, still shows data centres and semiconductor plants driving growth. For FY2026 itself, the January outlook put total peak demand across Japan's ten areas at 159.6 GW, with consumption of 803.4 TWh. OCCTO links this to the retirement of inefficient coal plants, many of which are being replaced with LNG-fired units on existing sites through Japan's long-term decarbonisation capacity auctions.

Japan's balancing capacity is mainly thermal plants burning coal and LNG, plus pumped storage. The war that began on 28 February closed the Strait of Hormuz and cut LNG exports from Qatar and the UAE. Japan's Seventh Strategic Energy Plan, approved by the Cabinet on 18 February 2025 alongside the GX2040 Vision, set out to deliver "stable energy supply, economic growth, and decarbonization simultaneously," with a target of cutting greenhouse gas emissions by 73% by FY2040 from FY2013 levels.

OCCTO itself urged attention to "risks rising from international situations" in deliberations on phasing out coal, a recognition that energy security considerations now weigh on decarbonisation timelines. For hyperscalers planning Japanese capacity, the message from OCCTO is that grid access in the Tokyo area will remain tight for several years, and the cost of the marginal megawatt will be set, in part, by events in the Gulf.