The 2.5 MW Liberty Wind Turbine is the largest wind turbine manufactured in the United States. The turbine was developed through a partnership with U.S. Department of Energy and its National Renewable Energy Laboratory for Clipper Windpower:
- "Designed to address current industry gearbox and other component deficiencies and minimize unscheduled maintenance events, the Liberty wind turbine distributes torque loads four times more efficiently than conventional machines through its patented Quantum Drive Distributed Generation Powertrain. Proprietary permanent magnet generator technology delivers higher powertrain efficiency, and variable speed operation is achieved in a simpler and more efficient manner. A 2-ton on-board crane simplifies maintenance and significantly reduces associated costs. Installation can be accomplished with a crane sized for most commercial 1.5 MW units."[1]
Commercial sales for the new Liberty turbine started in June 2006 and now amount to more than 5,600 MW (2,240 units) of firm and contingent orders for deliveries in 2007 through 2011.[1]
