Inzai / Greater Tokyo cluster

Digital Realty · NTT · AirTrunk · Inzai, Chiba, Kantō, Japan

Water — consumed, not returned

Taken from the basin2,185M gal/yr
Evaporated on site795M gal
Making the power1,390M gal
Basin stressMedium-High
Where the water comes from
Municipal potable supply
Cooling
Chilled water with evaporative towers; humid summers limit free cooling
Basis
Modelled from cooling design — WUE 0.74 L/kWh

Air — what the stacks emit

Nitrogen oxides648t/yr
Sulphur dioxide567t/yr
Fine particulates80.9t PM2.5
Health damages$72.8M/yr
Where it burns
Japan — TEPCO area
Generation mix
Gas 44 · Coal 28 · Solar 11 · Nuclear 6
CO₂e
1,785 kt/yr — climate, not air quality

Who wanted it

Who asked for it
Japanese enterprises and government, plus AWS, Microsoft and Google regions and SoftBank's AI buildout
Who approved it
Chiba prefecture and Inzai city; TEPCO supply — Japan's post-Fukushima gas-and-coal mix keeps carbon intensity high
What it serves
Japanese cloud regions, financial exchanges, and sovereign AI programmes
IT capacity
600 MW running of 1,100 MW announced

Japan's compute is concentrated on a seismic zone near Tokyo for latency reasons, on a grid that is still carbon-heavy because most reactors remain offline. Both AWS and Microsoft announced multi-billion expansions here in 2024–25.

coal-heavy grid

Where it is

35.8320°, 140.1450°

Water and air figures are modelled from disclosed capacity, not measured — site-level error is roughly ±40%. Diesel backup generators are not counted, so on-site figures are floors. Full method.