General about offshore wind power

General about offshore wind power

Industrial-scale wind power is divided into onshore and offshore wind power according to where the foundations of the turbines are located and where the power cables of the wind turbines are laid. The foundations of offshore wind turbines are either on the seabed or they are floating and their power cables run along the seabed. Turbines built on artificial islands may be classified as offshore wind turbines if their power cable runs on the seabed.

Offshore wind turbines are not different from onshore wind turbines in terms of their appearance. They too have a tower and three blades. However, today’s offshore wind turbines are considerably larger than onshore wind turbines, and in relation to the tower, the rotor is larger than in onshore wind turbines. In addition, their foundations and part of the tower are below the surface of the sea. The planning and construction of an offshore wind power project, as well as its operation and maintenance differ significantly from onshore wind power. Moreover, an offshore wind power project always involves underwater design and construction. Offshore weather conditions that can be challenging at times in both the construction and operation stages impose limitations to the operations: it is not necessarily possible to reach a turbine, for example, due to rough seas or thawing ice.

Offshore wind power in Finland

In Finland there is currently one offshore wind farm, and the foundations of its turbines are built on the seabed. The Tahkoluoto offshore wind farm in Pori has a total of eleven wind turbines, the first of which was completed in 2010 and the other ten in 2017. The total output of the wind farm owned by Suomen Hyötytuuli is 44.3 MW. In addition, eight of the 13 wind turbines in the Ajos wind farm in Kemi are built on artificial islands outside the port. The total output of the turbines built on artificial islands is 26.4 MW. The Ajos wind farm is owned by Ikea.

In Finland, there are currently several offshore wind power projects under development (see STY’s project map). The total output of the projects in different stages of planning is several thousands of megawatts. As a result of the decreased production costs of offshore wind power, interest towards offshore wind power is increasing rapidly also in Finland.

Offshore wind power on a global scale

Currently, offshore wind power is growing strongly throughout the world. However, the number of built turbines is still low in comparison with the number of onshore wind turbines: approximately five per cent of all wind turbines in the world are offshore wind turbines. For the time being, the main focus of offshore wind power has been strongly on Europe as three quarters of the world’s offshore wind power capacity is located in Europe. The superpowers of offshore wind power are United Kingdom and Germany. China is also building a lot of offshore wind power. In Europe, the Netherlands, Denmark and Belgium have also been active in offshore wind power.

Read more about European wind power statisticsista