For the past decade or so, offshore wind power has been confined to nearshore areas because the turbines must be anchored to the seabed with pile foundations. But nearshore resources are nearly exhausted, and there are increasing numbers of approval hurdles and environmental disputes. The real wind, in fact, lies in deeper waters.
I. Why Go to Shenzhen?
For fixed-bottom wind turbines, once water depths exceed 50 to 60 meters, the cost of pile foundations and construction rises sharply, quickly making the project uneconomical. Yet most of the world’s high-quality wind resources are located precisely in areas farther offshore and in deeper waters. Moving into deeper waters isn’t a matter of following trends—it’s a necessity dictated by the availability of resources.
II. Three Floating Positions
Floating wind turbines are secured to the sea surface by a mooring system, rather than being anchored to the seabed. There are three mainstream configurations: the semi-submersible type, which resembles a buoyant platform and is the most mature and common; the single-pillar (SPAR) type, which resembles a column deeply embedded in the water and is stable but has a deep draft; and the tension-leg platform (TLP) type, which is held in place by taut cables and is suitable for deeper waters.
| Route | Features | Applicable Water Depth | Maturity |
|---|---|---|---|
| Semi-submersible | Floating platforms: the most technically mature option | Moderately deep | Higher |
| Single-Pole SPAR | Deeply embedded floating piles: stable but with a deep draft | Deep | Chinese |
| Tension Leg Bridge (TLP) | Tighten the cable; respond quickly | Very deep | Demonstration |
III. Some people have already started running on the sea
Norway’s Hywind Scotland connected 30 megawatts to the grid as early as 2017, with its turbines standing in water nearly 100 meters deep; the Kincardine project in the United Kingdom followed shortly thereafter. China has also seen demonstration projects such as the “Three Gorges Pioneer” being deployed at sea one after another, bringing floating wind power from the pages of academic papers to actual construction sites.
IV. Obstacles We Haven’t Yet Overcome
The fatigue life of mooring systems and dynamic cables, the scarcity of deep-water construction vessels capable of installation, and the fact that the cost per kilowatt-hour remains higher than that of fixed-bottom systems are all major obstacles. Currently, the cost per kilowatt-hour for floating systems is still roughly between $80 and $90 to over $100, while fixed-bottom systems have already been reduced to $50 to $60.
Cracking the “deep-sea code” essentially involves replacing the foundation of a wind turbine—from concrete piles on the seafloor—with buoyancy and cables on the sea surface.