China has completed in Shanghai what it presents as the world’s first offshore data center (UDC) powered by offshore wind energy. Located off the Lin-gang special zone in Shanghai Free Trade Zone, the facility is driven by a commercial purpose and a clear goal: use the ocean to dissipate heat and offshore wind farms to supply nearly all renewable electricity. The project invests 1.6 billion yuan (around $226 million, close to €195 million), with a total capacity of 24 MW, over 95% green energy, and achieves 22.8% reductions in energy consumption compared to similar land-based centers. Additionally, it eliminates the use of freshwater for cooling and reduces land occupation by more than 90%.
From concept to operation: a leap from laboratory to market
The initiative begins with a first phase delivering 2.3 MW serving as an operational pilot, with plans to scale up to 24 MW in its initial commercial version. This isn’t an isolated prototype but a modular system designed to grow in cells. Each module encapsulates server racks inside sealed, corrosion-resistant containers that are anchored at approximately 35 meters depth. The stable temperature and maritime currents create a natural thermal sink, drastically reducing the energy needed for cooling.
The project is backed by a state consortium and local companies experienced in offshore wind, telecommunications, and port operations. This strategic combination involves: on one hand, nearby wind generation minimizing losses and dependency on the grid; on the other, connectivity and operations integrated into Shanghai’s industrial fabric.
Why submerge a data center (and why now)
Demand for AI-intensive computing and digital services is rapidly increasing, while in large cities land is scarce, freshwater resources are under pressure, and power grids face peak loads. In this context, the ocean offers several advantages:
- Passive cooling: the water mass acts as a high-capacity thermal dissipator, reducing auxiliary energy use compared to land-based cooling towers or chillers.
- Less surface footprint: shifting the core to the sea frees land parcels in urban areas and diminishes visual and noise impacts.
- No freshwater requirement: the design avoids evaporation and water resource consumption competing with urban and agricultural uses.
- Renewable coupling: offshore wind’s proximity and stability make it suitable for self-supply and lower transmission footprint.
The key performance indicator is the sector’s recognized metric: the PUE (Power Usage Effectiveness). The Lin-gang UDC aims for a PUE of 1.15, compared to an average around 1.25 for Chinese land-based centers. Practically, this means only 15% of total energy is used for non-IT purposes (cooling, losses, auxiliaries). At scales of tens of megawatts, reducing from 1.25 to 1.15 yields double-digit energy savings and consequently lower emissions.
Architecture: capsules, depth, and telemetry
The core of the system lies in hermetically sealed corrosion-resistant steel capsules housing servers, storage, and networking equipment. The depth of ~35 meters balances thermal stability, manageable pressure, and installation and maintenance costs. Heat from hardware is transferred via thermal jackets and sealed circuits that move heat to the surrounding water; local hydrodynamics handle the rest.
On the surface, a coastal station manages power, fiber optics, security, and remote operation. Sensors monitor temperature, vibration, humidity, and structural integrity, activating contingency protocols when needed. Daily operations—deployment of loads, software updates, observability—are similar to any modern data center, just with the “building” submerged.
Offshore wind as an energy backbone
The proposal builds on China’s massive offshore wind ecosystem developed in recent years. For the UDC, this translates into >95% renewable electricity, reduced exposure to price spikes, and the ability for local consumption of generation without overloading terrestrial grid infrastructure. Also, by not using freshwater for cooling, the facility reduces another major environmental cost of conventional data centers in warm or temperate climates.
Impacts and risks for the industry
The immediate benefit is a smoother cost curve for energy and a more favorable environmental profile, with less water, land use, and—if goals are met—improved efficiency. Additionally, proximity to large demand centers (Shanghai and surrounding regions) offers competitive latency for financial services, e-commerce, gaming, or AI inference near users.
The risk lies in operation and maintenance. Replacing hardware at 35 meters is not trivial: it requires maritime logistics, good weather windows, and specialized ships and equipment. The strategy involves designing for modularity (removing complete capsules for dry maintenance), using high-reliability components, and planning long intervention cycles. In a world of rapid updates—like GPUs changing every 18-24 months—there’s a need to plan block renewals and orchestrate load migrations without impacting SLA.
From Project Natick to commercial scale: an inevitable comparison
This deployment resembles Microsoft’s Project Natick, which proved the technical feasibility of underwater servers and recorded reduced failure rates during its Scotland phase. However, Natick was conceived as a research project, not a ready-for-market product. The novelty in Shanghai is the commercial intent and the integration with offshore wind from day one. Moving from prototype to service involves not only engineering but also procedures, insurance, certifications, and public metrics to build client trust.
Marine environmental impact: questions that will require answers
No offshore infrastructure is free from environmental considerations. Will need to monitor noise during installation, biofouling inside capsules, interactions with wildlife, and the decommissioning plan at end of life. The modular approach helps—capsules can be fully removed—but tracking with public indicators will be key to comparing its net balance against alternatives: free cooling in cold climates, liquid immersion, or sea water cooling in a closed loop on land.
Is replication in Europe or the Americas possible?
Potential exists. Europe has mature offshore wind zones, ports, and a consolidated maritime supply chain. United States is also advancing with its own deployments. However, environmental permits, social acceptance, and coastal governance are more demanding. Any similar project will need to demonstrate with verifiable data its actual PUE, availability, water use (WUE), carbon footprint, and resilience against storms and coastal risks. If Shanghai confirms PUE ≤ 1.15, >95% renewable, and reliable operation, the model may gain traction outside China.
Key metrics to watch moving forward
To measure actual success, the industry will monitor several metrics and evidence:
- Operational PUE sustained throughout the year, including summer peaks.
- Wind capacity factor and annual percentage of truly renewable energy.
- Availability (SLA) and incident rate compared to land-based centers.
- TCO per MW of IT, including maintenance logistics.
- Environmental impact monitored and published with transparency.
There will also be interest in what loads are prioritized: AI inferences, low-latency content for Shanghai’s metropolis, last-mile telecom services, or processing linked to China’s distributed computing strategy.
A future that’s no longer science fiction
While the industry discusses ideas like space data centers, China has chosen a pragmatic solution: the ocean as a natural radiator and offshore wind as a energy pillar. If the Lin-gang UDC delivers on its promises—efficiency, cleanliness, resilience, and cost competitiveness—it could set a pattern for new implementations alongside offshore wind parks. Success will depend less on the headline and more on everyday operation: open metrics, strict SLA contracts, and robust environmental plans.
Frequently Asked Questions
What is an underwater data center, and how is it cooled?
It’s an IT facility where servers are housed in sealed capsules submerged tens of meters underwater. The heat exchange with seawater allows heat dissipation with significantly less energy than land-based cooling, reducing associated electricity consumption.
What does a PUE of 1.15 mean, and why is it important?
PUE compares total energy consumption to the energy reaching the IT equipment. A PUE of 1.15 means that only 15% of the energy is used for non-IT purposes. Improving from 1.25 to 1.15 on a large scale saves energy and lowers emissions and operating costs.
What are the main maintenance and upgrade challenges?
Underwater logistics complicate hardware replacements and frequent upgrades. The approach involves modular capsules, high-reliability components, carefully planned intervention windows, and load orchestration to prevent SLA disruptions.
Can this model be replicated in Europe or Spain?
Yes, ideally in regions with offshore wind, ports, and a mature supply chain. It will, however, require strict environmental permits, public acceptance, and public verification of efficiency, renewability, and resilience to storms and coastal risks.
via: Gov.cn