On October 7, Japan's AI compute market saw two investments land in a single day: MC Digital Realty started construction of the KIX15 data center in Osaka, and AirTrunk added USD 1 billion to the TOK1 campus east of Tokyo for liquid cooling deployment. The two projects differ in scale and route, yet both treat liquid cooling as the foundational solution for high-density AI workloads. Energy storage is becoming part of the supporting infrastructure of AIDC.
1. KIX15: Liquid Cooling Reserved at the Design Stage of a New Campus
On October 7, MC Digital Realty, a 50/50 joint venture between Digital Realty and Mitsubishi Corporation, officially started construction of the KIX15 data center at its KIX campus in Ibaraki City, Osaka Prefecture. With an IT capacity of 24 MW, the project is scheduled for commissioning in Q4 2028. As the fifth data center at the KIX campus, KIX15 will bring the joint venture's data centers operating in Japan to ten, with a combined IT capacity of about 220 MW. The project adopts a hybrid air- and liquid-cooling scheme, with liquid cooling reserved at the design stage to accommodate mid- and long-term AI compute expansion. Included in the "Kansai AI Infrastructure Co-Creation Project", it serves hyperscale cloud providers, cloud service providers, and enterprises building their own AI compute capacity. With relatively ample land and power resources, the Kansai region has become the main landing point for foreign capital building compute clusters in western Japan.
2. TOK1: Liquid Cooling Retrofit for an Existing Hyperscale Campus
On the same day, AirTrunk, backed by Blackstone, announced an additional investment of USD 1 billion in its TOK1 campus in Inzai City, Chiba Prefecture, to deploy liquid cooling systems supporting high-density AI compute loads. TOK1 has a total capacity of more than 300 MW. The investment is matched by a USD 1 billion green loan led by Sumitomo Mitsui Banking Corporation, MUFG Bank, and United Overseas Bank. AirTrunk CEO Robin Khuda said TOK1 aims to become Japan's first large-scale AI compute campus; driven by geopolitical factors, a growing number of North Asian customers are choosing to locate their compute capacity in Japan.
3. Two Construction Routes, One Shared Signal
The two projects represent two approaches to building compute capacity in Japan. KIX15 is a greenfield campus with liquid cooling reserved from the design stage for long-term expansion; TOK1 is a retrofit of an existing campus, where liquid cooling upgrades will convert data halls originally serving general cloud business into AIDC, putting built assets to use and shortening the time to service. Different routes, one shared signal: as rack power density keeps rising, traditional air cooling can no longer support large-scale GPU clusters, and liquid cooling is shifting from an optional extra to a threshold requirement for high-density AIDC.
4. Japan as a North Asian Compute Node: Opportunities and Constraints
Japan is fast becoming an important alternative node for compute in North Asia. In the past, overseas cloud providers and compute service providers expanding in Asia preferred Singapore and Malaysia; today, geopolitics, compliance, and low seismic risk are steadily raising Japan's appeal. But the flip side of capital inflows is real constraint: Japan faces its own pressures on power supply, energy consumption approvals, and land costs. New AI compute projects generally need more than two years of construction; when this batch of projects comes online around 2028, the market's supply-demand landscape will change markedly.
5. CNESA Observation: Beyond Cooling, Power Supply and Backup Needs Rise in Tandem
Liquid cooling addresses thermal management, but high-density AI data halls are raising requirements for power supply reliability, emergency backup, and green power support at the same time, needs that energy storage is positioned to serve. UPS-integrated storage, data center backup power, and battery energy storage systems that participate in grid regulation are gradually becoming part of the supporting infrastructure of AIDC; with power supply tight in Japan, the urgency is even greater. For China's industries, both the liquid cooling and energy storage supply chains stand to win follow-on orders from the wave of overseas compute construction.
