At present, most of the world's wind power equipment is installed on land, but people have already turned their attention to the ocean.
1, 1990
Sweden installed the first experimental offshore wind turbine, offshore 350 meters, depth 6 meters, stand-alone capacity of 220 kilowatts.
2, 1991
Denmark built the world's first offshore wind farm on the northwestern coast of the Baltic Sea on Lolland Island and has 11 450-kilowatt wind turbines to power 2,000 to 3,000 inhabitants.
3, 2000
Megawatt wind turbines are beginning to be used offshore, giving offshore wind projects an initial commercial value.
4,2002 years
Denmark built the world's first large-scale offshore wind farm in the North Sea and installed 80 units of 2-megawatt wind turbines with an installed capacity of 160,000 kilowatts.
Subsequently, many European countries such as Sweden, Germany, the United Kingdom, Ireland, the Netherlands, Belgium and France were successively involved in the construction of offshore wind farms.
5, 2007
Outside of Europe, China is also currently building a large-scale offshore wind farm, with the first 1.5-megawatt offshore wind turbine installed in the Bohai Sea and connected to an independent grid of offshore oil fields.
6, 2010
Shanghai Donghai Bridge built the first grid-connected offshore wind farm with a total of 34 3 MW units with an installed capacity of 102,000 kilowatts.
The advantages of offshore wind power
The obvious disadvantage of developing wind power on the sea is that it is difficult to construct, difficult to maintain and costly, and it is generally believed that offshore wind power is 50% more expensive to develop than onshore wind power. Why should we build an offshore wind farm?
Wind power is the most critical factor in the size of the wind, which is generally superior to the winds at sea, offshore winds 10 km offshore are usually 20% higher than the coast wind power generation power and wind speed proportional to the cube , So the annual production of offshore wind turbines under the same conditions can be 70% higher than that of the land, meanwhile there is very little static wind period at sea, so wind power generation takes longer.Generally speaking, annual power generation of onshore wind turbines The number of hours is about 2,000 hours, while offshore wind turbines can often reach more than 3,000 hours.
For wind power equipment, the land topography is complex, the roughness is high, and the wind speeds at different heights often vary greatly, leading to wind shear and turbulence, resulting in unbalanced forces on the top and bottom of the wind turbine, which can cause blade vibration, fatigue and even breakage. The system is also vulnerable to damage, and there is very little risk at sea. In addition, offshore wind power is mostly built at dozens of kilometers from the coast and is close to the electricity center with no risk of abandoning the wind.
At the same time, as the capacity of wind turbines increases, the length of the blades also increases sharply, while blades of more than 60 meters and even hundreds of meters are very difficult to transport on land, but can be shipped directly from the leaf factory to the wind farm at sea .
With the development of terrestrial high-quality wind energy resources, offshore wind power is a foreseeable future as a development trend.As offshore wind power needs more specialized technologies and has broader applicability, in the future global energy supply system, offshore wind power The outlook will be broader than onshore wind.
China's offshore wind resources status
China's coastline is more than 18,000 km long and more than 6,000 islands. Compared with the land, China's offshore wind resources are more abundant. According to the detailed investigation and evaluation results of China's wind energy resources by China Meteorological Administration recently, The level of 5-25 meters water depth of wind energy technology development is about 200 million kilowatts, 5 to 50 meters deep water area of about 500 million kilowatts.
Distribution of Wind Energy Resources in Various Coastal Areas of China
The numerical simulation of wind energy resources shows that the Taiwan Strait is the most abundant offshore wind resource in China, and offshore wind resources in Guangdong, Guangxi and Hainan south of the Strait are also good.From the north of Fujian Province, the offshore wind resources are gradually reduced to Bohai Bay However, the reasons for abundant wind energy resources in Fujian, southern Zhejiang, Guangdong and Guangxi are related to typhoon and other tropical cyclone activities, and the impact of disaster weather needs to be considered in the development.
Offshore wind energy resources are an important part of China's national energy development strategy.China's wind power 13th Five-Year Plan proposes to build 15 million kilowatts of offshore wind power by 2020 (including 5 million kilowatts and 10 million kilowatts under construction) Under the guidance of national planning, the medium and long-term plans of offshore wind power in the province have been successively formulated with a total planned capacity of 74.22 million kilowatts. Among them, Shandong, Jiangsu, Fujian and Guangdong Provinces are the provinces with planned kilowatts above scale.