Floating Wind Turbines
The winds over our oceans can generate a great deal of power, but due to the depth of the water, it’s not plausible to attempt to mount wind turbine towers in deep water areas. Floating wind turbines simply extend the standard shallow water wind turbine plans, to include mounting on a structure that floats, to allow for use in deeper water.
Using wind farms that are on the ocean also lessens the look of the large turbines, since some people do not wish to see them – or hear them – near their homes. |
HyWind |
The wind is often stronger and more consistent on the oceans as well, without land formations that can deflect the flow of winds.
When areas are planned for sea-based wind farms, the moorings and turbines can often be assembled on land and then towed to the desired area. Floating buoys with attached turbines may utilize weights on anchor cables, to give them extra tension and support. One of the earliest large-capacity turbines is the Hywind (pictured above), which is moored off the coast of Norway, in the North Sea. It was assembled in waters much calmer than those found in the area where it was deployed.
It is believed that there is potentially an enormous global market for floating offshore wind turbines, even though they are largely looked upon by the public as things that are still far off in the future. Still, a Hywind installation has been planned off the coast of Scotland. In addition, a WindFloat turbine (pictured below) has also been installed off Agucaduora, Portugal.
The foundation of a floating wind turbine improves the stability of the structure, allowing for it to withstand turbine-caused motion and sea waves. The platform is moored with four lines, and two are connected directly to the turbine support column. As the winds change direction and thus the load on foundation and turbine, a floating structure uses a secondary hull-trim system that shifts the ballast water between the columns. This keeps the platform relatively even, while still producing energy.
WindFloat
Since oil rigs have lasted for years in open waters, it is believed that floating wind turbines should also be able to show a long survival rate. At issue is the fact that there was money coming in for the continued use of oil rigs, and that type of financial situation is too early to tell yet for deep water turbines.
For floating turbines that are to be used in deep water, the structure has to be buoyant enough that it can support the turbine weight. The movement from the turbine itself and from water and wind must also be within specified limits. The distribution of power will also be more costly, since turbines used in deeper water will need longer transmission lines.
Certainly, more is now understood about the feasibility of floating wind turbines, especially those that will be used in shallow waters. It is felt that these structures will become economically and technically feasible in the coming years, as the world looks for more power to satisfy its increasing demands.
External Links – Sources
Wikipedia: http://en.wikipedia.org/wiki/Floating_wind_turbine
Guardian: http://www.guardian.co.uk/environment/2012/apr/23/us-uk-floating-wind-turbines