1.1 Offshore wind market - 2012
In Europe, every year since 2000, new offshore wind turbines have been coming online. At the end of 2012 there were 1,662 turbines totalling 5 GW of installed offshore wind capacity spread across 55 Figure 1). They produced 18 TWh, enough electricity to power almost five million households.in 10 European countries (
Offshore wind represents 10% of the annual wind energy installations across Europe. This is only the beginning of major global industrial development, led by Europe.
Most of the offshore projects (3.2 GW or 65% of total capacity) are located in the North Sea. 16% of total capacity is located in the Baltic Sea and 19% in the Atlantic. There are currently no offshore wind farms in the Mediterranean, because the water is deep, and current commercial substructures are limited to 40m to 50m maximum depths. This restricts the potential to exploit offshore wind development in the Mediterranean.
With the exception of two turbines, Europe's grid connected offshore wind turbines rely on fixed foundations, and the vast majority of those on monopile foundations. Gravity based substructures are the second most common foundation type, followed by space frame structures.
FIGURE 1 ANNUAL AND CUMUlATIVE INSTALLATIONS OF OFFSHORE WIND IN EUROPE (MW)
FIGURE 2 TYPICAL FIXED OFFSHORE FOUNDATIONS
At the end of 2012, there were two full scale grid connected offshore wind turbines on floating substructures, Hywind and Windfloat. Both are located in Europe, one in the North Sea and one in the Atlantic.
- Hywind is developed by Statoil, with a 2.3 MW turbine. Installed in in 2009, it is the first large scale floating wind structure installed in the world.
- Windfloat, the second large scale floating system, was installed off the Portuguese coast in 2011 and started to produce energy in 2012. Developed by Principle Power and EDP, it is equipped with a 2 MW Vestas wind turbine.
Seven experimental floating substructures (four in Europe, two in 2.and one in the US) are in a test phase: SeaTwirl, SWAY, Blue H and Poseidon in Europe, Kabashima Island concept and WindLens in Japan and DeepCwind floating turbine in the US. In addition FLiDAR is a floating Lidar, an offshore meteorological station designed for marine renewable energy technologies such as offshore wind, wave and tidal
FIGURE 3 SHARE OF SUBSTRUCTURE TYPES FOR ONLINE WIND FARMS, END 2012 (UNITS)
- SeaTwirl was installed and tested in Sweden, and subsequently decommissioned.
- SWAY, developed by SWAY, was installed in Norway. The experimental concept, a 1:6 downscaled model is not grid connected.
- The first phase of Blue H was installed in the summer of 2008 along with a small wind turbine in 113 m deep water, 11.5 nautical miles (21.3 km) off the coast of southern Italy, near the site of the future offshore Tricase project. After six months at sea, the unit was decommissioned early in 2009.
- Poseidon 37, constructed by Floating Power Plant, was installed and tested in 2008 at Vindeby offshore wind farm, off the coast of Lolland in Denmark.
- DeepCwind consortium installed a 20 kW floating wind turbine in the Gulf of Maine in June 2013.
- In Kabashima Island (Japan) a 100 kW wind turbine is grid connected and undergoing testing.
- In Hakata Bay, a scale model with two wind turbines of 3 kW each on one floater are installed and grid connected.
The European offshore wind industry is in its infancy and has huge potential for cost reductions and technological innovation. It is increasingly developing deep offshore designs for water depths of over 50m to unlock market potential. EWEA notes that in addition to two full scale deep offshore turbines at the end of 2012, there are three grid connected experimental floating substructures and thirty five deep water designs under development worldwide. Of all forty projects identified, either grid connected systems or under developement, twenty-seven (more than 60%) are located in Europe, in nine countries: Denmark, France, Germany, the Netherlands, Norway, Portugal, Spain,and the UK. Four (10%) are in the US and nine (23%) in Japan.
FIGURE 4 LOCATION OF DEEP WATER WIND ENERGY DESIGNS (BASED oN NUMBER OF PROJECTS ANNOUNCED)