GreenEnergyForEarth.com – Solar & Wind Power Products

Nov 11, 2009 – The world’s largest offshore wind park, Horns Rev II, recently commenced operations.  The facility, which is located in the North Sea, consists of 91 Siemens wind turbines for generating electricity.  The wind farm has a maximum output of about 210 MW, enough to meet the electricity needs of approximately 200,000 households.  Each of the turbines from Siemens Energy has a rated output of 2.3 MW, as reported in the most recent issue of the research magazine Pictures of the Future.  Each turbine weighs 300 tons and rises more than 100 meters above the water’s surface.  Each of the 60 meter-high towers carries three 45-meter-long rotor blades, whose tips sweep through the air at 220 kilometers per hour on windy days. T he angles of the blades can adjust themselves in line with the wind speed in order to catch as much of the wind’s force as possible.  The 82-ton nacelle to which the rotors are attached also rotates independently in the wind.  Innumerable sensors on and inside the nacelle measure the vibrations of the individual machine parts.  If unusual values are measured, the system sounds an alarm, allowing damage to be detected before it happens.  The turbines are manufactured by Siemens in Denmark.  A particularly challenging aspect of the rotor blades is the fact that they must be extremely flexible yet strong in order to handle high winds.  To overcome this difficulty, Siemens uses a unique patented process in which the rotor blades are made in one piece with alternating layers of balsa wood and fiberglass that are encapsulated in epoxy resin.  As a result, the blade does not have any potentially weak areas such as joints or adhesion points.  The rotors are designed to operate reliably for 20 years.  Such a high level of reliability is especially important for offshore facilities because maintenance work is about ten times as expensive on the high seas as on dry land.
Like solar energy, wind energy is one of the most promising sources of renewable electricity for the future.  Experts estimate that wind energy will generate 13 times as much electricity worldwide in 2030 than it does today, covering around 8% of total electricity needs.  The German government aims to generate around 25,000 MW of electricity from wind power by 2030, and therefore it plans to build 40 new wind parks in the North and Baltic Seas, encompassing a total of about 2,500 wind turbines.  Wind turbines are part of Siemens’ portfolio of environmental products, which generated sales of €23 billion for the company in business year 2009.  This makes Siemens the world’s leading provider of environmentally friendly technology.

Photo courtesy & © Siemens