How Tokyo Metro may help Japan solve its 'Big' data centre problem

Japan is exploring the possibility of building data centres beneath a section of the Tokyo Metro. This test comes as part of efforts to address space and infrastructure challenges linked to rising data demand. A consortium of four Tokyu Group companies announced plans to install a modular data centre beneath an elevated section of the Oimachi Line starting in June 2026, to study whether such setups can operate reliably in railway environments.The trial comes at a time when Tokyo’s data centre market is facing infrastructure constraints. Last year, Yasuo Suzuki of NTT Global Data Centers told Data Centre Knowledge that power grid connection wait times in central Tokyo can take five to 10 years. According to Mordor Intelligence, land costs in Japan have also increased, with prices in Tokyo rising by 69% in 2024. The city currently has 132 operational data centres, with at least 18 more under construction. Meanwhile, medium-sized facilities are growing at a 12% compound annual growth rate through 2031, as they are easier to deploy in space-constrained urban areas than larger facilities.The goal of the trial is to determine whether compact server infrastructure can perform well under active railway overpasses, where vibrations, noise, and temperature changes are common. The modular unit will fit servers, cooling systems, and a power supply into a container-sized enclosure that can be set up without building a whole building. Tokyu Electric Railway will provide the land, Tokyu Construction will build the unit, and It's Communications will connect it to fibre-optic cables already along the railway.During the trial, the consortium will evaluate factors including sound insulation, thermal performance, vibration isolation, and cooling efficiency under real-world railway conditions. The group will assess the findings to decide if they can scale and deploy the model at other locations across the Tokyu network.One factor the consortium is relying on is the existing optical fibre network built by It's Communications Corporation along Tokyu’s rail lines. Instead of laying new fibre connections, these under-track data centres could connect directly to the current network infrastructure. The group also said it is exploring expanding similar deployments across the wider Tokyu Line network, including areas such as Shibuya, as part of a longer-term digital infrastructure plan.