“Clipper’s new proprietary technology is an evolutionary advancement of wind energy variable speed systems which increases wind turbine reliability, and decreases costs associated with maintenance,” said Amir Mikhail, Ph.D., Clipper Windpower’s senior vice president and technology engineering leader. “This technology is made possible by recent solid-state technology advances in the form of larger capacity switching transistors (Integrated Gated Bipolar Transistors “IGBT’s”), and the use of proprietary permanent magnet generator technology.“

Over the past decade, wind turbine variable speed systems have commonly utilized a doubly-fed generator with the generator rotor wired directly to dual IGBT’s. At generator speeds below synchronous (low wind speeds), current flows into the generator rotor, and, at super-synchronous higher wind speeds, current is drawn out to maintain the turbine’s desired power output frequency. As the current is transferred, it is conducted through high power slip rings and brushes.

“Historically, we have learned that the use of a doubly-fed generator wired directly to dual IGBT’s can induce stray currents in the generator rotor shaft, commonly damaging slip rings and brushes which, thereby, have traditionally required ongoing maintenance,” said Mikhail. “Stray currents have also been responsible for pitting generator bearings, which many times have led to costly generator failures.”

Through the Clipper variable speed system, power is delivered exclusively from the generator’s stator where it is rectified to DC current. Modern-day IGBT technology is utilized to convert the DC power to AC current, maintaining the unit’s desired grid frequency.

“Through Clipper’s variable speed process, including the use of unique permanent magnet generator technology, the need for troublesome slip rings and brushes is negated,” added Mikhail. “Ongoing testing of the Clipper variable speed system conducted since March 2005 on Clipper’s first production unit, the 2.5 megawatt Liberty® I wind turbine, sited in Medicine Bow, Wyoming has validated the system’s high reliability design.”

Clipper’s variable speed technology is being utilized in the production of the company’s 2.5 megawatt Liberty wind turbines, currently in production at its Cedar Rapids, Iowa assembly plant. The Liberty Series, designed to address current industry gearbox and other component issues, mitigates gearbox stresses through Clipper’s patented Quantum Distributed Generation Drivetrain (“DGEN-Q”). Simpler, more effective grid integration is achieved through power factor regulation technology with ride-through capability which exceeds current and planned standards for electric grid operation. Clipper’s permanent magnet generator technology delivers higher powertrain efficiency, and a 2-ton on-board jib hoist simplifies maintenance and significantly reduces associated costs. The 2.5 MW Liberty turbine installation can be accomplished with a crane sized for most commercial 1.5 MW units.

About Clipper Windpower

Clipper Windpower, www.clipperwind.com, is a rapidly growing wind energy technology, turbine manufacturing, and wind project development company. With offices in California, Colorado, Maryland, Mexico and the U.K., and ISO9001:2000 QMS Certified manufacturing and assembly facilities located in Cedar Rapids, Iowa, the company designs advanced wind turbines, manufactures its 2.5-MW Liberty wind turbine and actively develops wind power generating projects in the Americas and Europe. In September 2005, Clipper completed a successful IPO on the London Stock Exchange's Alternative Investment Market (AIM). Clipper's ticker symbol is CWP.

The ordinary shares of Clipper Windpower are traded on the Alternative Investment Market of the London Stock Exchange and are not registered under the U.S. Securities Act of 1933, as amended. Such shares may not be offered or sold to residents of the United States or to persons acting on their behalf, or to other persons who are "United States Persons" within the meaning of Regulation S as promulgated under the Securities Act of 1933, unless such shares have been registered under the Securities Act or there is an available exemption from registration.

###

For more information contact:

Mary McCann-Gates
Director, Global Communications
Clipper Windpower Inc.
6305 Carpinteria Avenue, Suite 300
Carpinteria, CA 93013
(main) 805.690.3275
(direct) 805.576.1323
(fax) 805.899.1115
(mobile) 661.301.0400
mgates@clipperwind.com

Back to Press Releases