China has completed the first phase of construction of what it claims is the world's first underwater data center (UDC). Located in Shanghai’s Lin-gang Special Area with a price tag of roughly RMB 1.6 billion ($226 million), it's a significant milestone in the quest for sustainable solutions to the growing energy demands of China’s computing infrastructure.

Powered entirely by wind energy, the initiative has a total power capacity of 24 megawatts. According to the Lin-gang management committee, its completion represents a key breakthrough in incorporating renewable energy into data storage, processing, and distribution.

Beneath the Surface

Traditional land-based data centers run hot and must be kept cool to operate efficiently. Air conditioning systems alone can account for up to 50 percent of total energy consumption.

Lin-gang's UDC solves this problem by submerging servers beneath the surface of the ocean where seawater acts as a natural cooling system, according to Su Yang, general manager of Shanghai Hicloud Technology, one of the contractors on the project. This reduces the energy demand for cooling to less than 10 percent.

The underwater data center uses seawater as a natural cooling system. Illustration: Shanghai Hailanyun Technology

The industry-standard metric for measuring the energy efficiency of a data center is PUE (power usage effectiveness). The UDC’s first phase is designed to achieve a PUE of no more than 1.15, a remarkable goal considering theoretical perfection is 1.0. Meanwhile, China’s national policy requires new data centers to achieve a PUE of less than 1.25 by the end of 2025.

The project is environmentally sustainable in other ways. More than 95 percent of its electricity comes from offshore wind turbines. Overall, the designers estimate that this reduces energy consumption by 22.8 percent. Huang Dinan, president of Shenergy Group, another of the project’s contractors, noted that the East China Sea offers unique offshore wind resources with more than 3,000 hours of annual utilization. Land usage is reduced by more than 90 percent, a major factor in densely populated coastal cities like Shanghai, and the need for fresh water is eliminated entirely.

From East to West

The UDC is not an isolated effort. As part of a broader national strategy in China, Shanghai aims to become a global center of scientific and technological innovation by growing its cloud computing industry to more than RMB 200 billion (approximately $28.25 billion) by 2027.

This initiative also complements—and perhaps offers an alternative to—the “East Data, West Computing” megaproject, which launched in 2022. That project seeks to build data centers in China’s less developed, western regions to process data generated by coastal economic centers to the east. Lin-gang's UDC, on the other hand, processes data close to where it is generated, while using marine resources to mitigate negative environmental impacts.

The Winds of Change

The UDC’s 24-megawatts capacity is just the beginning. During the announcement for the project, the main contractors, including Shanghai Hicloud Technology, Shenergy Group, the Shanghai branch of China Telecom and INESA, signed a new agreement to launch another offshore wind-powered UDC project with a much more ambitious goal: 500 megawatts.

However, the transition from proof-of-concept projects to large-scale application presents significant challenges. “UDC construction is still in its early stage,” cautioned Wang Shifeng, president of Third Harbor Engineering, another company involved in the current project. Wang stressed that for broader deployment, operation and maintenance optimization, as well as technological reliability, must be achieved first.

This story originally appeared on WIRED en Español and has been translated from Spanish.