Sitting 50 miles off Guangdong in 174 feet of South China Sea water, 33 turbines with 958-foot rotor spans became the first cluster of 18-megawatt offshore machines ever to enter full commercial operation
One blade on each of these machines is longer than a ten-story building is tall.
That fact is easy to miss until the rotor starts turning.
On September 24, a 2 GW offshore wind farm logged full commissioning in Chinese grid records.
Turbine ratings above 20 MW are already in prototype testing elsewhere, and vessel logistics remain a binding constraint for developers building farther from shore.
Each machine sweeps nearly 710,000 square feet of open ocean air with every revolution, driven by 33 massive turbines rated at 18 MW apiece.
So what engineering buried beneath 50 miles of seabed makes the whole thing work?
Why 50 miles of undersea cable is an engineering problem all by itself
Electricity traveling through a long undersea cable behaves differently from electricity moving across an overhead line on land. Reactive power bleeds away as it travels, and the longer the cable, the worse the voltage instability becomes at the receiving end.
At 50 miles, that problem grows severe enough to destabilize the grid connection entirely without a correction system along the route. To solve it, the operator built what Chinese grid engineers describe as the country’s first 500 kV compensation station installed offshore, steadying voltage before it reaches land and preventing fluctuations that would make the farm’s output unusable at scale.
Without that station, the 2 GW of nameplate capacity would have been undeliverable. The compensation platform, not the turbines, was the gating item for commissioning.
A rotor so wide it rewrites the scale of what offshore wind looks like
A total of 131 turbines were installed across the two sub-projects, including the 33 units rated at 18 MW. Those machines carry a rotor span of 958 feet, wider than three football fields laid end to end, and a swept area of roughly 710,000 square feet.
At full load, one rotor revolution generates about 43 kWh, enough to run a refrigerator for roughly six weeks, and each turbine can produce up to 56 million kWh annually. The remaining 98 turbines fill the lease area and bring combined rated capacity to 2 GW.
The site sits in water up to 174 feet deep on fixed-bottom foundations anchored to the seabed south of Nanpeng Island. That depth is within reach of conventional jacket structures, but the sheer mass of an 18 MW nacelle assembly pushes installation vessels toward their upper limits even in relatively shallow water.
What the records actually show from September 24
Full commissioning was logged on September 24, recorded by the grid operator and confirmed by the developer in a public statement the same day. The project is the first in China to deploy 18 MW offshore turbines at commercial scale, and no other offshore wind farm anywhere has brought this many turbines of this unit capacity into simultaneous operation.
The farm is expected to supply more than 6.6 TWh of electricity annually, avoiding roughly 1.92 million metric tons of standard coal consumption and 5.1 million metric tons of CO2 emissions per year. Those are projections, and the first full production year will be the real test of whether the array meets them.
The distance that keeps maintenance crews honest
Fifty miles is a long way to travel on a service vessel before the work even begins. In the South China Sea, typhoon season runs roughly from May through November, compressing the reliable maintenance window into a narrow corridor of calmer months.
Weather downtime at distance can mean a crew spends more hours in transit than on the turbine. A single mechanical fault on one of the 18 MW machines demands a vessel large enough to carry components weighing hundreds of metric tons, and the 500 kV compensation station adds another remote asset with no close precedent in Chinese offshore operations.
Similar long-cable challenges shaped logistics decisions at Block Island’s successor off Rhode Island, where undersea cable routing was among the last infrastructure elements locked before first power flowed. What the distance does to cost per megawatt over a farm’s lifetime remains the open question for developers in Europe and the United States, where 50-mile cable runs are becoming the norm as near-shore lease areas fill up.
What a 2 GW farm of 18-megawatt turbines tells the rest of the industry
The central argument for very large turbines has always been that fewer machines cover the same capacity at lower installation cost per MW: fewer foundations driven, fewer vessel trips, fewer cable connections. Yangjiang Fanshi puts that argument on the record for the first time at this turbine rating.
Before this farm, 18 MW machines existed only as prototypes or single-unit demonstration installs. Now 33 of them are spinning together, feeding a transmission system purpose-built to carry their output across 50 miles of open water, a different kind of proof from a test site.
The scale race is far from finished. Turbine ratings above 20 MW are already in prototype testing elsewhere, and vessel logistics remain a binding constraint for developers building farther from shore. What Fanshi adds is a full commissioning record: 131 turbines, projected annual output of 6.6 TWh, and the world’s first offshore 500 kV reactive compensation station, all signed off on a single September day. The projections still have to survive a full year of South China Sea weather, but the machines are turning and the grid is receiving what they send.
Hugo is an engineer with strong technical expertise. Multilingual from an early age, his writing combines technical clarity with a strong interest in science and energy.
