China offshore wind energy

A self-elevating wind turbine installation vessel has been delivered to a subsidiary of China Communications Construction Company.

China is the world leader in wind power generation, with the largest installed capacity and continued rapid growth in new wind facilities. With its large land mass and long coastline, China has exceptional resources: it is estimated China has about 2,380 GW of exploitable capacity on land and 600 GW on the sea.

The vessel, developed by Shanghai Zhenhua Heavy Industries Co., Ltd., integrates multiple functions such as large equipment hoisting, installation and transportation.

It is 90 meters long and 40.8 meters wide. With a deck area of 2,400 square meters and a variable load of around 3,200 tonnes, the ship can accommodate three six-megawatt wind turbines or two eight-megawatt wind turbines.

High-precision installation can be achieved even under huge waves up to five meters high and during strong gales brought by a super typhoon, its developer said.

Offshore wind power has picked up steam with more countries installing gigantic turbines in their coastal waters. Wind turbine installation vessels can help overcome difficulties during the construction process.

After the delivery, the vessel will serve China’s offshore wind farms and promote the country’s construction of offshore wind power facilities.

Offshore wind resource assessment seems to be urgently needed due to the rapid development of offshore wind energy in the coming decades.

Technical potential of offshore wind energy over the sea area shallower than 250?m along China coast is investigated.

Influential factors including wind power density, water depth, wind turbine size, wind farm layout and various spatial constraints are analyzed on the GIS platform.

It shows that wind resource at Taiwan Strait is particularly abundant, where wind power density at 70 m height can be above 900W/m2. Technical potential is quite sensitive to the size of wind turbine. Taking the layout S1 (8×15 wind turbines in each farm, 8 rotor diameters apart between wind turbines, 20 km buffer region between neighboring farms) as an example: the total technical potential of the study area is 613 GW for rotor radius 60 m, and that for rotor radius 90 m is 1,264 GW; the growth rates of technical potential with rotor radius is 19.3 GW/m roughly.

Spatial constraints has significant impact on the region with water depth less than 50 m, where only 48.1% of area is available for developing wind energy and the technical potential there is about 23% of that area.