In Europe, offshore wind energy will be a major form of RE in the near future due to the high wind energy resources in the sea and the limited land space for development of onshore wind farms.
As of 2006, offshore wind turbines are produced based on the same technologies as for onshore wind turbines. Very large wind turbines of 2 MW or higher rated power are usually adopted for offshore applications. 5 MW turbines have been developed for offshore applications, and even larger ones are being tested.
For a large offshore wind farm, the wind turbines are arranged in the form of an array. High-voltage submarine cables connect the wind turbines to a substation on an offshore platform, where the voltage is further stepped up for transmission by submarine cables to an onshore substation.
The cost per kW installed capacity of an offshore wind farm is higher than that of onshore wind farms, due to the higher cost of construction of marine foundations and offshore platform, higher cost of delivery of materials and components to the offshore site, and the use of costly submarine cables.
Offshore wind turbines are usually installed in near-shore waters (several kilometers away from the shore), because the water depth will not be too high and power transmission cost is lower.
A number of offshore wind farms have been built in European countries like Denmark and UK. It was reported in the news that a number of offshore wind farms have been planned in the Mainland (This web page has hyperlinks which may transfer you to third-party website.http://www.huaxiawind.com.cn/detail.asp?infoId=18), including one at Nanao in the nearby Guangdong Province.
Locally, the power companies and wind energy developers are also studying the feasibility of constructing offshore wind farms in Hong Kong waters. In 2006, two Applications for Study Brief under the Environmental Impact Assessment Ordinance were submitted to the Environmental Protection Department, for offshore wind farms in Hong Kong waters. Interested persons can visit the following link for details: This web page has hyperlinks which may transfer you to third-party website.http://www.epd.gov.hk/eia/ (click on "Applications for EIA study brief", then on "2006")