High-tech remedies

18.05.2015
Camera-equipped drones provide high-end display photos. (Photo: Batcam)
Camera-equipped drones provide high-end display photos. (Photo: Batcam)

So far, there has been no remedy for blade tip erosion. Problems can take quite a while to be detected. New systems are intended to speed up work on the blades.

Why take the trouble of hanging off of a rope if there are easier ways to do it? Indeed, many companies offer drones and ground-supported camera systems for servicing rotor blades. High-tech lenses supply images of rotor blades’ conditions with impressive resolutions. These photos can help experts conveniently assess a blade’s condition at their computers and decide if any action needs to be taken. This is intended to reduce the use of work platforms (see page 24) and the need for workers to climb with ropes (see also page 38), thereby saving costs. According to the manufacturers, a well rehearsed team should be able to check on several turbines per day depending on the system, reducing forced turbine downtimes and, in turn, revenue ­losses by using these visual inspections.

However, potential markets must be carefully evaluated. In Germany, for instance, these technologies stand almost no chance because of very strict inspection rules. Besides, insurance companies in the country already require regular visual inspections and a blade assessment conducted by experts at least every four years. In many instances, these inspections must even be carried out every two years. Because such short intervals are sufficient for detecting damage, there is little need for costly camera ­systems and drones.

The situation is different for offshore wind and other markets, because there are no requirements in terms of time for regular rotor blade inspections – and out at sea, such inspections are rather time consuming and expensive. In such cases, these systems can therefore certainly make sense for operators who need an overview of the condition of these vital energy generators.

Considerable zoom

Drones are one high-tech device that can help here. However, these unmanned aerial vehicles (UAVs) do have a number of problems – at least when blade inspection comes into play. One issue is that they cannot carry much weight and are rather susceptible to wind. Another is that their batteries only work for a limited amount of time and need to be exchanged fairly often in order to prevent the expensive ­technology from falling out of the sky.

Availon GmbH of Germany carefully researched these issues before ordering a customized UAV from Dutch specialists Aerialtronics. After a test phase, the service provider is now advertising its drone – primarily outside of its home country, because of German air traffic regulations. The UAV is equipped with an anti-collision system to prevent collisions with, for example, a rotor blade in strong winds. “Even at wind speeds of 12 m/s, the drone is stable in flight and the camera delivers incredibly sharp photos,” Project Manager Marcel Bruins reported ­after a test phase.

Pages

Similar Entries

WINDSOURCING.COM broadens its product portfolio and adds BASF Coatings’ RELEST® repair program for rotor blades to it. Herewith the company further extends its position as the world's major sales portal for wind turbine products.

The Offshore Renewable Energy (ORE) Catapult, in collaboration with Centrica, has successfully delivered the first in-field measurement campaign under its industry-leading blade leading edge programme (BLEEP), and concluded that an uplift in annual energy production (AEP) of between 1.5 to 2% is possible following the repair of moderate blade erosion.

KTA Kunststofftechnologie Aurich GmbH, ENERCON’s rotor blade manufacturer, successfully completed the production of the first set of outer rotor blades for ENERCON’s new low wind speed WEC E-141 EP4. The blades are intended for the E-141 EP4 prototype that is currently under construction in Central Germany. At present the WEC components are assembled at the construction site. “We are well on schedule with the installation,” says Arno Hildebrand, the EP4 programme manager. “The installation of the rotor blades is scheduled for mid-November. Commissioning is planned before end of the year.“

The world’s longest wind turbine blade passing a traffic roundabout. (Photo: LM Wind Power)

Specialist for heavy transports Mammoet Wind transported the world’s longest wind turbine blade from Danish Lunderskov to Aalborg over a distance of more than 200 km. The blade was transported from a pilot plant of LM Wind to the Blaest Blade Test Center.