GE Demonstrates Blade Extension Technology at WINDPOWER 2014

Addition of seven-meter sections to turbine blades resulted in 20 percent output boost in prototypes


At WINDPOWER 2014 in Las Vegas, GE demonstrated its new blade extension technology which takes GE wind turbines from a 77-meter rotor to a 91-meter rotor by adding a seven-meter extension to the turbine’s blades. The extension increases the swept area of the rotor by 40 percent and increases the energy production by more than 20 percent.

The technology was implemented in two prototypes that have now been in operation for 10 months. The prototypes were completed with Noble Environmental Power at Noble’s Clinton Wind Park in Clinton, New York.

The technology upgrades GE 1.5-77 turbines to GE 1.5-91 turbines utilizing the entire existing blade asset. The program was developed by GE to help customers achieve significant increase in power output on their existing fleet while maintaining existing product life and acoustics. Throughout the development of the extensions, the GE team filed more than 16 patent applications and developed custom tooling for the extension installation.

“The blade extension program for GE is a great example of the magnitude of technology advancements GE is capable of developing,” said Mark Johnson, engineering leader for GE’s renewable energy business. “At GE, we take big swings to help our customers reach their goals and operate more successfully. Achieving production gains of more than 20 percent for existing units is a challenging task, and with GE’s expertise in engineering aerodynamics, material science, structural engineering and controls, we continue to be able to help our customers operate more profitably and efficiently.”

Advanced technologies developed to make the project a reality include the unique, centrally located insert, improved methodologies and advanced controls for loads mitigation. The extended blades have undergone testing beyond IEC requirements, including static strength tests that are standard for all GE-engineered blades and fatigue tests totaling more than 6 million cycles. The model and process utilize the existing design margins of the 1.5-77 turbine in lower wind speed applications. In addition to the extended blades, modifications were made to controls and parts to adjust for the added loads on the turbine.

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