In a first, China takes data centres underwater to tackle cooling challenge

China is testing an underwater data centre off Shanghai to cut cooling costs; the pod uses ocean currents for low temperatures and mostly renewable energy

Imagine storing the internet beneath the waves. That is the ambitious plan of a Chinese company aiming to tackle one of computing’s biggest challenges: energy-hungry data centres. By submerging servers in the sea off the coast of Shanghai, the project hopes to reduce the massive cooling costs that come with running modern digital infrastructure, AFP reported. 

On a wharf near Shanghai, workers are putting the finishing touches on a large yellow capsule. This underwater pod, developed by maritime equipment firm Highlander along with state-owned construction companies, represents a bold step into alternative technology infrastructure. 

Unlike land-based data centres that rely on energy-intensive air cooling or water evaporation, undersea servers use naturally cold ocean currents to stay at low temperatures.

 

A global first

Microsoft experimented with a similar idea off the coast of Scotland in 2018 but never moved forward with a commercial rollout. In contrast, Shanghai’s upcoming project, set to be submerged in mid-October, will be the world’s first operational underwater data centres. It is expected to serve major clients, including China Telecom and a state-owned AI computing firm, reflecting China’s efforts to reduce the carbon footprint of its data infrastructure. 

The Microsoft project was primarily about demonstrating feasibility. The company conducted its trial in 2020, confirming it was technically successful but pointed out construction and operational challenges. 

In China, government subsidies are supporting such ventures. Highlander received 40 million yuan ($5.62 million) for a 2022 Hainan project, which is still running. 

The Shanghai pod is built onshore in separate parts before installation in the sea and will rely mostly on power from nearby offshore wind farms. Highlander says over 95 per cent of energy will come from renewable sources. 

Protecting servers and marine life

Keeping the servers dry and safe from saltwater corrosion is a major hurdle. The company uses a protective coating containing glass flakes on the steel capsule. An elevator connects the submerged pod to a segment above water for maintenance access. Laying internet connections underwater is also more complex than for land-based servers, the AFP report said. 

However, marine ecologists caution about the environmental impact. The news report quoted Andrew Want from the University of Hull as saying that the heat given off by underwater data centres could attract or repel certain species. Highlander cites a 2020 assessment of its test project near Zhuhai, which found water temperature remained safe.

Future of subsea servers

Despite challenges, experts see underwater data centres as complementary rather than replacement infrastructure, the news report said. If successful, this Shanghai experiment could offer a glimpse of a more energy-efficient, ocean-based approach to powering the digital world.