The world’s installed wind power capacity in 2006, according to the Global Wind Energy Council, was 60 000MW with an average annual market growth rate of 28%. Although this represents only about 1% of the installed global electricity generation capacity, wind power in 2006 had a global market value of about &Euro; 13 billion (USD 17.5 billion).
But this growth is not without its problems, one of them being where to put the turbines, particularly near densely-populated areas. Offshore locations, although more expensive to build than land-based installations, help to solve the problems of land use and disruptive noise produced by the rotor blades. Additionally, offshore allows for much larger projects than are possible on land.
The International Electrotechnical Commission (IEC) is putting together a series of International Standards on wind turbines and this part – IEC 61400-3 – specifies requirements for assessing the external conditions at an offshore wind turbine site. It spells out five essential design requirements to ensure the engineering integrity of these structures. Its purpose is to provide an appropriate level of protection against damage from all hazards during the planned lifetime.
While the standard emphasizes the engineering integrity of the structural components of an offshore wind turbine, it also deals with subsystems, such as control and protection mechanisms, internal electrical systems and mechanical systems.
Prepared by IEC Technical Committee 88, Wind Turbines, the first edition of IEC 61400-3 Design requirements for offshore wind turbines, is scheduled for publication in the fourth quarter of 2008.
