For the European Union (EU), offshore wind power is viewed as central to the group's commitment to generate 20 percent of its energy from renewables by 2020. Its potential highlights why. According to the European Wind Energy Association (EWEA), if barriers are removed, up to 40GW of offshore wind energy could be operating in the EU by 2020, supplying four percent of Europe's electricity. The figures look promising, but the crux of this technology's future lies in the phrase, “if barriers are removed.”

The challenges include the problems associated with connecting to the electricity grid, and here than has been much talk of the need for a well-developed maritime grid infrastructure. There are also the difficulties associated with its impact on the local environment, the competition for space with other marine users, and this feeds into the importance of effective and timely authorization procedures. In addition, there are issues related to financing, operation and maintenance costs, and a shortage of skilled personnel.

With these issues in mind, earlier this year the European Commission launched a public consultation to identify the key barriers to the large-scale uptake of offshore wind energy. This is expected to lead to an action plan, slated for October or November, and it is hoped that it will help guide policy, and provide solutions where necessary.

This will obviously be important to the industry as a whole, but what has been apparent in recent months is that there have been a fair few column inches given to a type of offshore wind technology that may already be able to overcome some of these barriers. And the technology in question has been bobbing around for some time. It is the “floating wind turbine.” Though still in its infancy in terms of development, even in the nascent wind power industry, a number of groups believe it has serious potential.

There are a plethora of these in Norway. One of them is the large Norwegian company, StatoilHydro. It has decided to build the world's first full scale floating wind turbine, Hywind, 10km offshore of Karmøy in the county of Rogaland in Norway, with a planned start-up in autumn 2009.

This will then be tested over a two-year period. The company says the project combines known technology in an innovative way. A 2.3MW Siemens wind turbine is attached to the top of a spar-buoy, a solution used in production platforms and offshore loading buoys, and the flotation element will be moored to the seabed using three anchor points. The wind turbine can be located in waters with depths ranging from 120m to 700m.

StatoilHydro has also recently invested in Norwegian group, SWAY, which is developing turbine floaters. The company says that its turbines can be anchored in ocean areas with several hundred metres of water using a massive gravel-filled anchor, and its 200m-tall buoy is designed to sway with the wind and waves and withstand extreme weather conditions. It talks of 2010 for the possible launch of a prototype.

Another is WindSea, a joint enterprise between Norwegian groups Statkraft, NLI Innovation and Danish-based FORCE Technology, which earlier this year launched the Windsea triple turbine, consisting of three towers and three turbines—one in each corner of a triangle-shaped, floating platform. The platform will be anchored to the seabed by a single chain so it can rotate as the wind changes direction. The group states that this makes the plant far more stable, simplifies access for repairs and maintenance, and preliminary calculations show that the investment cost per installed MW is competitive compared with alternative concepts.

And on the other side of the North Sea is Blue H Technologies, a firm registered in the UK, but based in Holland. It may have stolen a small march on some of the others as it has recently anchored its prototype device 12 miles off the coast of southern Italy in water 108m deep. The Blue H prototype will float a turbine platform on the sea surface and fix it in position using strong chains linked to heavy weights on the seabed. Changing the length of the chains could allow the turbine to operate in water depths between 50m and 300m.

Whilst there are obviously differences between the various technologies outlined, the potential benefits highlighted are very similar in nature.

Firstly, there is the traditional “not in my backyard” syndrome. The floating wind turbines concept allows wind farms to be located further out to sea, which means they can be invisible or virtually invisible from the shore. Another benefit of their placement is the strong and steady wind further out at sea, so the turbines should be able to generate more electricity in comparison to their near-shore counterparts. Secondly, there is the positioning of offshore turbines, and the associated competition for space. Floating wind turbines offer mobility, maneuverability, and given that they can potentially be located in deepwater regions, there is less intrusion on shipping, military radar and coastal seabird populations. Bringing these first two points together, this might also allow for the deployment of larger turbines, which in turn may further reduce the cost per KWh of offshore wind. And thirdly, there are the economies associated with providing fixed foundations in the seabed. Floating wind turbines do not require this, which reduces the overall weight of the structure, a huge element in the cost component of offshore wind units.

However, there are obviously many issues and challenges still to be resolved. The technology needs much more testing and some analysts believe that costly offshore repairs could quickly drive up costs. And many also believe that state subsidies will need to play an active role to get the technology up and running. As with any maturing technology, overcoming the technical, cost and commercial hurdles are never easy. The road from research and development to commercialization and onto large scale development may be long.

Nevertheless, the potential upside is clearly evident. And if the EU wants to meet its 20 percent renewables target by 2020 it will need to ask questions of, and look to leverage all the technologies available. With offshore wind, perhaps some of the answers are floating in the wind?