Saving over $1 million: wind turbine inspections with the Elios 3

Benefits in a nutshell

Wind energy is one of the original forms of power generation, seeing an early form in windmills and agriculture. Now, wind turbines are helping to power the planet. In 2022, 7.33% of global energy was generated by wind. 

However, wind turbines are incredibly complex to build, transport, and inspect. Production worldwide is moving incredibly quickly, but a single blade for a land-based turbine can be over 170 feet (52 meters). The largest wind turbine in the world, the Goldwind GWH252-16MW, has a turbine rotor diameter of 827 feet (252 meters) and its hub stands at 479 feet (146 meters). The large size of turbine blades makes them incredibly difficult to mount, and the process of inspection and maintenance is also complex. 

Inspectors have been trying to find safe ways to inspect turbines before and after they go into operation. These inspections can be used to ensure the lightning protection built into the turbines is correctly configured, as well as to ensure there are no cracks or degradation inside the turbine. There can be a risk of grease or missing bolts inside the blades that can be dangerous if it builds up - or, in a lightning strike, if it ignites. 

The Elios 3 is being used by Pathfinder Optics to enable safer and faster inspections of some of the biggest wind turbines in America.

Developing drone inspections for the renewable energy industry

Joseph Valenzuela is the Operations Manager at Pathfinder Optics, a specialized robotics and drone inspection company. Joseph’s extensive experience as a drone pilot makes him the ideal person to inspect wind turbines. He started working with UAVs after an early career as a non-destructive testing technician. Joseph found that many inspections required work at height or confined spaces, and wanted to use robotics as a safer alternative. From this passion and drive, Pathfinder Optics was born. 

Now, Pathfinder Optics uses a fleet of various robotics and drones to conduct inspections across multiple industries and has developed a niche area of specialty: wind turbine inspections. As part of these inspections, Joseph uses the Elios 3. He highlights the LiDAR capabilities of the drone in addition to the visual feed as a game-changer; he can now elevate the outputs of his inspections and outpace competitors.

How drones can be used for wind turbine inspections

Joseph initially used a rotary drone without an exoskeleton-like cage for inspections at wind turbines but has found that the Elios 3 is the ideal tool for the job. The protective structure of the Elios 3’s cage helps him move with confidence inside the small spaces of turbine blades, while the LiDAR and visual data provide key data that is needed for inspections. 

For a recent project, Joseph had to inspect 4 turbines at a site. He needed to climb up to the hub of the wind turbine - the space between all three blades  - and conduct inspections inside each blade. Before climbing up, each turbine was turned off and all blades were stationary. 

The small area from where Joseph can access the separate wind turbine blades 

The first challenge is access. Joseph has to climb up a ladder to get to the hub while carrying the drone. For this reason, the Elios 3’s portability makes it an even more useful tool. At some sites, it is also possible to winch the drone up using cables while Joseph climbs.  

Once inside the hub, Joseph is in a small space that has access hatches to each of the turbines. Each blade can be flown within 1 battery life as Joseph navigates the drone 220 feet down the structure before returning. After all blades have been inspected, Joseph can then carefully climb back down. 

With this method, Joseph inspected 4 turbines in 1 day. This would not be possible with traditional methods, where even 1 turbine a day can be the maximum operational speed.

Image right: The Elios 3 flies inside the turbine blades with ease, but saves inspectors time and energy in inspecting the cramped space. 

Benefits of using a drone for wind turbine inspections

The visual and LiDAR surveys conducted by Joseph are critical for monitoring the status of wind turbines. The hub holds technical infrastructure and a CMS to manage the wind turbine, including how the blades are pitched and how they turn. However, this CMS cannot monitor the blades themselves as these are made of fiberglass. If the blade is for some reason damaged, the CMS cannot determine why or how. This is when inspectors will have to respond to a fault, and Joseph’s fast operational speed with the Elios 3 makes him the best person to provide a solution for this challenge. 

A single blade being destroyed or significantly damaged can cost over $1 million to replace. This huge cost can be averted if inspections provide information prior to a problematic event. An example of a problem like this could be lightning. Turbines typically have a lightning protection system in place that includes metallic conductors placed along the edges of the blade and connected to the hub. However, if these are not correctly configured, the blade can explode in a lightning strike, or catch fire. If there is a build-up of grease in part of the blade when this happens, the explosion can become even more serious. 

The interior of the wind turbine is clearly visualized with the Elios 3's LiDAR scan

When Joseph conducts an inspection, he can use the Elios 3 to identify manufacturing defects or potential hazards and report these back to the wind turbine owner or manager. They can then take quick action to conduct maintenance or organize a planned replacement, which is significantly cheaper than a repair replacement of $1 million or more. 

Wind turbines also have to be inspected every year or twice a year, depending on the local regulations. This used to require a person to have to step out and walk inside the blades or crawl inside them. This was a huge fall risk and presented a major problem for turbine owners. 

Now, with the Elios 3, concerns for employee safety as well as expensive maintenance can be resolved. Joseph’s current workflow is incredibly efficient - he can climb up a tower and inspect it before returning to the ground within 3 hours. In the past, this could take half a day if not longer. 

In addition, drones can be used for emergency response should the worst happen. In rare cases, there can be a turbine fire. These are usually caused by lightning. Another potential issue is a grease leak. These scenarios require a rapid response with quick decision-making. By using a drone, Joseph can quickly respond to these emergency scenarios and provide key information about what is happening without anyone having to climb or even approach the turbine.

Bringing modern drone technology to renewable energy

Joseph has found that bringing the Elios 3 to his wind turbine inspections has helped him to work more quickly while staying safe. Joseph told Flyability, “I am no fan of big heights, and this drone helps me to work quickly and safely while minimizing how long I have to be up there. It is a challenge for anyone to inspect this area, as there can be a fear factor as well as a major fall risk. The drone ensures I can stay in the safety of the hub and be harnessed down without having to crawl into the turbine blades.” 

Joseph is conducting saver turbine inspections with the drone and working faster than ever

Since Pathfinder Optics began conducting inspections for wind turbines, Joseph has completed projects all along the West Coast of the USA. He knows that using the drone is not only safer for inspections, but helps the wind turbine owners save costs and avoid lightning damage. All of this is possible because he relies on the Elios 3 drones to help keep him safe even in confined, challenging spaces at height.

Discover more about the Elios 3 and its specialized LiDAR payload

All images in this article are credited to CLP Power.