Why China is dunking data centers into the ocean

China is building wind‑powered, underwater data centers off the coast of Shanghai to reduce electricity used for cooling and to avoid the heavy freshwater draw typical of land facilities.

By using seawater as a heat sink and pairing modules with nearby offshore wind, planners aim to cut cooling power and lower the carbon intensity of compute capacity.

The first commercial phase, led by a domestic operator, targets a few hundred AI‑capable servers across roughly 200 racks, with ambitions to expand if early operations meet efficiency and reliability targets.

The approach emphasizes modular pods assembled onshore and deployed at sea to speed installation near coastal fiber routes and power sources.

Cooling with seawater, powering with wind

Undersea modules circulate seawater through radiators behind server racks to carry away heat, replacing evaporative or chilled‑water systems common on land.

Coupled with offshore wind feeds, the concept pursues a lower‑carbon profile for high‑density compute workloads.

Did you know?
Cooling systems can account for a large share of a data center’s electricity usage, which is why siting and cooling design often drive both costs and environmental impact.

From pilot pods to commercial rollout

Earlier experiments with sealed, nitrogen‑filled subsea capsules suggested potential reliability gains by reducing corrosion and human‑error incidents.

China’s program seeks to leap from pilots to commercial operation, compressing timelines and integrating with established maritime infrastructure.

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Promised gains: energy, water, reliability

Proponents expect meaningful drops in cooling electricity, sharply lower freshwater consumption, and fewer hardware failures in sealed modules.

Coastal siting also relieves land pressure in crowded metros and can colocate computing near subsea cables.

Open risks: ecology, security, scalability

Marine scientists advise monitoring localized warming near outlets, particularly during heat waves that strain ocean ecosystems.

Security concerns include the resilience of subsea assets to tampering or acoustic interference, and operators must plan for safe maintenance in rough seas.

Scaling from hundreds to thousands of racks will test economics, network latency, and serviceability versus efficient land campuses.

What to watch next?

Key milestones include verified power‑usage effectiveness, water impact monitoring, stable wind‑power integration, and multi‑season uptime data.

Regional interest is growing, but broad adoption will hinge on clear environmental safeguards, robust security practices, and cost parity with modern land‑based designs.