AtTokyo and elleThermo Validate Waste Heat-to-Power Technology in Live Japanese Data Center Trial
April 29, 2026
AtTokyo and elleThermo Validate Waste Heat-to-Power Technology in Live Japanese Data Center Trial
Japanese data center operator AtTokyo and waste heat-to-electricity firm elleThermo have successfully completed a demonstration project testing the commercial viability of converting low-grade thermal energy into usable power at operational data center facilities. The initiative marks a significant step toward reusing the vast amounts of heat generated by IT infrastructure, which is typically dissipated into the atmosphere without economic value.
The pilot evaluated elleThermo’s Semiconductor-sensitized Thermal Cell (STC) technology at two of AtTokyo’s facilities in Tokyo: the Chuo Center (CC1) and Chuo Center 2 (CC2). STC devices were installed in hot-aisle containment zones, air-conditioning mechanical rooms, and UPS rooms—areas where ambient temperatures typically range between 30 and 40 degrees Celsius (86–104 degrees Fahrenheit). Unlike conventional waste heat recovery systems that rely on high temperature differentials, STC technology is designed to operate effectively within the moderate thermal conditions common in data center environments.
According to the companies, the trial confirmed that power generation was achievable across all installation locations. The project also quantified how performance varied by environment and validated the technical feasibility of converting otherwise unused thermal energy from data centers into electricity. This was the first real-world validation test for elleThermo’s STC technology at an active data center site.
Following the successful demonstration, both firms signaled their intention to collaborate on further development of the technology to improve energy efficiency and reduce environmental impact, aligning with broader sustainability goals across the data center industry. AtTokyo operates approximately 13 data centers across Japan, including facilities in Tokyo, Osaka, Fukuoka, and Sapporo. Its CC1 facility is the company’s largest, with a capacity of 70 megawatts, and is part of a larger cluster that includes CC2 and the recently launched CC3, which entered service in 2024 with a capacity of 40 megawatts. AtTokyo’s investor base includes Tokyo Electric Power (Tepco), Japanese security firm Secom, and IT consultancy Intec.
Source: datacenterdynamics
