WIND FARMING

Wind Farming

Wind Farming

Offshore wind farming has picked up steam during the last decade? with more & more countries installing these gigantic turbines in their coastal waters. The largest wind farm in the world is located of the coast of Jutland? in the North Sea. An even larger farm has been given the green light for off the coast of Britain. One of the largest offshore areas in the U.S. with shallow water is off Cape Cod? where a major wind farm has been proposed. The construction of these farms has given rise to a new class of ship: the Turbine Installation Vessel (Greiner, 2008).

In fact a wind farm is a group of wind turbines in the same location used for production of electric power. Individual turbines are interconnected with a medium voltage (usually 34.5 kV) power collection system and communications network. At a substation? this medium-voltage electrical current is increased in voltage with a transformer for connection to the high voltage transmission system (Sovacool, 2009). A large wind farm may consist of a few dozen to several hundred individual wind turbines? and cover an extended area of hundreds of square miles (square kilometres) ? but the land between the turbines may be used for agricultural or other purposes. A wind farm may be located off-shore to take advantage of strong winds blowing over the surface of an ocean or lake (Greiner, 2008).

The first purpose built TIV was the TIV Mayflower Resolution? currently known as the TIV Resolution & owned by MPI Offshore. This vessel utilizes both dynamic positioning & jack-up technology. Equipped with 6 retractable legs? the Resolution will set up on location using DP? then elevated out of the water using the jack-up legs. This provides a stable platform to install the turbine on top of a previously prepared foundation. Once installed? the Resolution lowers back down to the water & moves to the next location? where the process is repeated. She has the capacity to carry 10 wind turbines (Sovacool, 2009).

Offshore wind turbines are less obtrusive than turbines on land? as their apparent size and noise is mitigated by distance. Because water has less surface roughness than land (especially deeper water) ? the average wind speed is usually considerably higher over open water. Offshore installation is generally more expensive than onshore? depending on the location. Offshore towers are a fair bit taller than onshore towers once the submerged height is included? making the foundation more expensive to build. Offshore saltwater environments also raise maintenance costs by corroding the towers? but fresh-water locations such as the Great Lakes do not. Repairs and maintenance are usually more costly than on onshore turbines? motivating operators to reduce the number of wind turbines for a given total power by installing the largest available units. Offshore saltwater wind turbines are outfitted with extensive corrosion protection measures like coatings and catholic protection? which may not be required in fresh water locations. Transporting large wind turbine components (tower sections? nacelles? and blades) is ...