Source: Science and Technology Daily, Reporter: He Liang
Recently, in the Yangjiang waters of Guangdong Province with a water depth exceeding 45 meters, the “Mingyang Tiancheng”, the world’s largest single-unit floating offshore wind platform, was officially commissioned.
The “Mingyang Tiancheng” boasts a unique design. It carries two wind turbines on a floating foundation and is anchored to the seabed, resembling a pair of “twin stars” floating on the sea surface. This is a global first in the field of offshore wind power.
Each of the two wind turbines has an installed capacity of 8.3 megawatts, giving the “Mingyang Tiancheng” a total installed capacity of 16.6 megawatts. With an annual electricity generation capacity of 54 million kWh, it can meet the daily electricity needs of 30,000 households with three members each for a year. Visit our products here
Optimal Solution Through Extreme Design
The “Mingyang Tiancheng” has a swept area exceeding 52,000 square meters, equivalent to seven standardized football fields.
On the “V”-shaped tower, the dual main engines and dual rotors of the wind turbines stand side by side, with only a 5-meter gap between the blade tips of the two rotors. Wang Chao, director of the Mingyang Group’s Floating Special Technology Innovation Center, told reporters that this extreme design represents the optimal solution after comprehensive consideration of rotor spacing, wind energy utilization efficiency, and the angle of the “V”-shaped tower.
The 5-meter gap is not only a safe distance between rotors but also maximizes wind capture. Wang Chao explained that after the wind turbines start, the two rotors rotate in opposite directions, effectively increasing the wind speed in the middle area between the rotors, thus enhancing the efficiency of converting air kinetic energy into electrical energy. Monitoring data shows that the power generation capacity of the dual wind turbines of the “Mingyang Tiancheng” is 4.29% higher than that of a single wind turbine with the same swept area.
Moreover, from the perspective of the entire wind farm layout, the longer the blades of a single wind turbine, the greater the impact of wake flow on subsequent turbines. Therefore, to reduce wake flow effects, the “Mingyang Tiancheng” adopts a scheme with two smaller rotor diameters. Additionally, the two rotors rotate in opposite directions, and the resulting “coupled vortex” effect reduces efficiency losses across the entire wind farm. Visit our products here
Single-Point Mooring System for Typhoon Resistance
Zhou Mingjun, the chief designer of the “Mingyang Tiancheng,” told reporters that the platform adopts a downwind design. This design reduces the restraint of the tower clearance on the blades, allowing the blades to have greater movement space while also capturing wind energy more flexibly and effectively, thus improving the power generation efficiency of the entire unit.
Under extreme conditions, floating wind turbines will face challenges from typhoons coming from all directions. The wind power platform must consider typhoon loads from all 360 degrees during the design phase to ensure that the wind turbines can withstand and remain stable regardless of the typhoon’s direction.
“We adopt a single-point mooring system, where the floating foundation platform can make adaptive yaw adjustments according to the typhoon’s direction under the traction of the anchor chain,” Zhou Mingjun explained. This means that wherever the typhoon blows, the “Mingyang Tiancheng” will turn to face it, ensuring that the rotors are always aligned with the incoming wind direction.
In the mooring system, to ensure that the wind turbine can withstand typhoons up to Category 17 at sea, the high-precision slewing bearing within the turret must have sufficient bearing capacity and superior underwater sealing ability. Zhou Mingjun introduced that to ensure the stable operation of the “Mingyang Tiancheng” at sea, the research and development team completed the assembly of the turret system according to extremely high standards and precision requirements. Visit our products here
Floating Foundation Enhances Bearing Capacity
The floating foundation is a critical component for floating wind turbines to “settle and thrive” in deep and distant seas. Unlike traditional steel-structured floating foundations, the floating foundation of the “Mingyang Tiancheng” consists of three pontoons, concrete arms, and connecting components.
The three pontoons are composed of various materials such as glass fiber shells, extruded polystyrene foam board cores, and protective coatings, which is an industry first. Wang Chao explained that such “elaborate efforts” are not only to reduce the weight of the pontoons but also to meet the requirements of the pontoons’ curved shapes.
Standing in front of the model, it can be seen that the three pontoons of the “Mingyang Tiancheng” are streamline ellipsoids. Wang Chao said that this shape design not only encounters less wave resistance when facing waves but also provides corresponding lateral rotational yaw power. In-depth verification and testing of the pontoon shapes showed that the streamline ellipsoid design achieved the best balance between overall stability and load.
It is worth mentioning that the “Mingyang Tiancheng” also adopts ultra-high-performance concrete materials with compressive strengths exceeding 115 MPa for the first time to manufacture the floating foundation. This concrete material has a strength approximately four times that of ordinary concrete, significantly increasing the bearing capacity of the floating foundation structure. Visit our products here
