Carpinteria, California [RenewableEnergyAccess.com] Clipper Windpower Plc announced its 2.5-megawatt (MW) Liberty C96 Class IIB and C93 Class IIA wind turbines have received Germanischer Lloyd (GL) certification for operation in extreme cold climate conditions.The achievement marks the first large wind turbine over 2 MW to receive the new GL extreme temperature certification. “With the ability to survive extreme cold climate conditions, including non-operating temperatures of -40 degrees Centigrade, the Liberty turbine offers a new level of confidence for demanding cold climate regions, including Canada, the northern United States, including North Dakota, Minnesota and Iowa, and northernmost European and Asian countries,” said Dr. Amir Mikhail, Clipper’s Senior Vice President and Chief Technology Engineer. “Because the Liberty Series was engineered at the outset to operate in extreme cold climate conditions, only minimal technical and operational changes were necessary to attain compliance with GL’s new extreme weather certification process,” said Mikhail. Liberty’s standard “low temperature survival” architecture includes metallurgical suitability of components, including main base, rotor hub and gearbox housing. Large, quality, high-strength nuts and bolts are also a Liberty standard, as is special low-viscosity gearbox oil and an immersed gearbox heating system, keeping oil temperatures above 0 degrees Centigrade at start-up. Heavy, cold-weather grease is applied to exposed pitch and yaw bearings. An internal heating system protects sensitive power electronics in the frequency converter and CPU. Liberty is also equipped with a generator heater, which is used when the generator is cold soaked for a period of time. Clipper’s Liberty wind turbines are currently in full production at the company’s manufacturing facility in Cedar Rapids, Iowa. During 2007, 75 MW of Liberty units will be equipped with the company’s extreme cold climate package for projects to be located in Minnesota. At a 2.5-MW capacity, the Liberty machine is the largest wind turbine built in the United States.