For a faster turnaround on blade repair one company suggests bringing them down to the ground and putting them in the company’s enclosure or habitat under controlled environmental conditions. The method eliminates the stand-by periods that often accompany bad weather and up-tower repairs.
“Three blades on one turbine can be refurbished and returned to service on the turbine in 48 hours,” says Daniel Boon, General Manager of GEV Wind Power and a former wind technician.
Boon points out several advantages of working on the ground versus up-tower: Two teams of two technicians working around the clock in 12-hour shifts do the work of composite structural repairs, repairing the leading edge, and applying a leading-edge protection. In the habitat, temperatures can be maintained above the lowest needed for two-part materials.
“Plus, those working on the ground need not have the rope-access training, so their hourly charge is lower. Weather is less of an influence, so the seasonal repair window is wider than with other repair methods. And working on the ground lets a tech focus more easily on the job and less on safety issues,” he adds.
The company designed and built the patented Ventura habitat, an inflatable enclosure for blade repairs by technicians using blade-climbing platforms. Boon’s team realized that while the suspended habitat worked well, it worked just as well on the ground. The platform version is still available, and a truck-mounted platform version is currently in design.
The biggest issue with blade repair is wind. “Bringing the blades down eliminates the issue. With a special cradle, it only takes about an hour to get the blades to the ground, and another 30 minutes to erect the habitat over the blade,” says Boon.