Carbon Fiber Spar Repair

SparDamage01Lightning strikes wind turbine blades every day. Most of the strikes are dissipated to ground as the lightning protection system (LPS) on the turbine is designed to do; however, some strikes will have enough energy to cause damage to the blades. With the advancement of longer blades, carbon fiber is being used more widely in the blade structure to add strength and stiffness and reduce weight. Since carbon fiber is an electrical conductor, lightning current can conduct through the carbon fiber structure causing major damage.

On this project, the lightning contacted the carbon fiber spar blasting holes through both sides of the spar and burning the structural laminates. Also, the shells on both sides of the blade and the leading-edge joint were damaged badly. Due to the severity of the damages, this blade was deemed unrepairable and a total loss by the OEM and the insurer.

Our repair team and composite engineers reviewed the damages and determined the blade was repairable, and we developed a cost-effective repair procedure. This repair was over 2.5m (8.2ft) long, and included removal of a large area of shell on both sides of the blade to gain access to the structural spar. This image was taken after all the damage was removed, the spar carbon layers were scarfed, and the spar inner biaxial fiberglass laminates were replaced. For removal of the damaged unidirectional carbon fiber layers, we used a 100:1 scarf ratio, which provided gradual load transition to the repaired layers. We replaced several layers of carbon fiber, added reinforcement doubler plies and elevated heat cured the laminates to ensure the resin matrix achieved full structural properties.

Once the spar damage was repaired, the LE joint was rebuilt and additional biax laminate wraps were applied to reinforce the LE joint. We then rebuilt the missing portion of the shells on both sides of the blade, starting with an inner skin lamination, followed by foam core installation and top skin lamination. Once all layers have cured, the repaired surfaces were filled and faired to duplicate the original blade contours. The final steps were application of two coats of polyurethane paint and new LEP tape.

This blade has been in continual service with no issues since it was repaired in 2012. We have performed dozens of these structural carbon spar repairs. To reduce turbine downtime and eliminate crane costs, most of these repairs have been done up tower utilizing our large, stable, wrap-around suspended platform.

For more information on damage repair, please call or email us.

Why Performance Composites?

  • Expertise
  • Experienced with all major turbines and blade manufacturers
  • Dedicated group of skilled composite engineers and technicians with years of education and hands on blade experience.
  • Specialized on composites repairs. We have experience with all types of damages and we understand the root causes so we will repair the blades properly.
  • Great track record on repairing structural damages including carbon fiber spars and tip replacement.
  • Provide accurate assessment of damages and will advise if the turbine can continue to run and how to monitor the damages.
  • Provide technical support on blade defect negotiation with turbine manufacturers.
  • Investigate serial defects and develop strategy to mitigate the risk and repair the damages.
  • Quality
  • Two year warranty, double the industry standard
  • Every blade repair is performed to OEM standards, following work instructions and using specified materials (no short cuts).
  • Utilize engineering composite standards on structural repairs and follow the specified scarf ratios. Repairs are as strong or stronger than original.
  • Employ state of the art, proprietary Computerized Maintenance Management Software (CMMS) to provide technicians with step by step work instructions, create detailed reports with clear pictures, and provide customer access to the reports via web portal.
  • Reliable
  • Dependable services and long-term partnership
  • Earn the trust of our customers. We take pride in our integrity and always do the right thing. If we make a mistake, we will own it and make it right.
  • A team of safe employees supported by great training and process
  • Continuous communication with site management to ensure effective management of the project.
  • Transparent in all the work we perform and billing we submit.
  • Environmentally conscientious and will clean up after the project so the jobsite is the same or better.
  • Cost-Effective
  • Advocates for owners & operators to reduce costs
  • Reduce turbine downtime by rapid response of crews and repairing damages as quickly as possible.
  • Work with our customers to be proactive and develop great blade maintenance and repair strategy.
  • Work with our customers to schedule inspection and repair during low wind season
  • Reduce mobilization costs by scheduling crews that are located regionally
  • Utilize heated tent enclosures to perform on-ground major blade repairs to reduce delay caused by weather or cold temperatures.
  • Our technicians are available for other on site work to reduce standby costs during bad weather.

Company Information

Performance Composites provides reliable wind turbine blade repair, inspection and consulting services. We are blade and composite experts with a dedicated group of experienced engineers and technicians focused on quality. We are advocates for turbine owners and operators and we will help you develop cost effective solutions to maintain your blades for a 20+ year life.

Contact Information

  This email address is being protected from spambots. You need JavaScript enabled to view it.
  +1 (800) 466-1140
  Physical Address:
1650 Vision St. Suite 245 Abilene, TX 79602
  Mailing Address:
P.O. Box 6225 Abilene, TX 79608