Wind energy is well established in Australia’s renewable generation portfolio, with the nation’s meteorological and topographical factors lending themselves as excellent wind resources. With the Federal Government’s recent introduction of a framework supporting offshore electricity infrastructure, wind generation opportunities are only expected to grow. But, as with any rapidly adopted technology, wind power presents distinct challenges which have established themselves over time.
According to Geoscience Australia, the wind energy industry is “the fastest growing renewable energy source in many countries and is expected to continue to grow rapidly over the period to 2030”.
Wind turbines present multiple challenges with regard to maintenance; they are tall, large and often installed in remote locations. As the technology shows no signs of slowing down, the tools and skills required to carry out turbine maintenance have struggled to keep pace.
Although operators seek fast and safe maintenance, teams are required to work at height repairing or replacing heavy equipment, which is risky, difficult work.
The challenges
Here, we examine the four biggest challenges when it comes to maintaining wind turbines, and keeping wind farms operating at their best. We’ll also consider some of the unique solutions that have been developed to enhance the performance and life of wind farms around the world.
1. Yaw brake replacement
The yaw component of a wind turbine facilitates the orientation of the wind turbine rotor towards the wind. The yaw brake secures the position of the nacelle upon re-orientation. The difference in yaw brake caliper weight can vary from 60-200kg. With some turbines, featuring up to 20 yaw brakes to control their position, this can place a substantial amount of strain on maintenance personnel, particularly given the scale of modern wind farms. In addition, many turbines lack in-built elevators, meaning maintenance personnel may have to climb a 100m-high ladder before repairs can even commence.
2. Resurfacing brake discs
Yaw brake discs are typically large in size and weight, with the servicing of them previously requiring a total disassembly of the large turbine nacelle. Discs are prone to suffer wear as the turbine rotates to face the wind, with small imperfections growing and thereby compromising the smoothness of the disc surface. This can result in a deterioration of braking performance until failure occurs. Disc replacement cant be time consuming, often requiring costly cranes which increase downtime and reduce energy output.
3. Removing glazing to reduce noise
A phenomenon known as ‘glazing’ can result in noisy wind turbine brakes, which can disturb both local residents and wildlife. When there is no wind and low usage, yaw brake discs begin to collect dirt, rust, and moisture as temperatures fluctuate. When the wind returns and braking begins again, this detritus is collected by the brake pad. Under high braking force, it is pressed tightly into the pad and disc surface, creating glazing. The result is a reduction in braking performance, compromised safety, and excessive noise, but unfortunately, once accrued, this glazing is difficult to remove.
4. Cleaning up yaw brake dust
Braking systems produce harmful dust substances that present a contamination risk to the local environment, a challenge that has been a focus of the automotive industry for many years. The dust also poses a risk to maintenance personnel who come into close contact with it for an extended period of time. Large installations with multiple turbines require the careful selection of environmentally-friendly brake pad materials.
The solutions
Wind turbines’ return on investment (ROI) potential is dependant on their ability to operate reliably. Therefore, a capable and responsive global aftermarket service partner is imperative for maximising electrical output and safeguarding profitability of installations.
Altra Motion has three decades of experience in wind turbine braking systems, and offers solutions to meet the needs of the entire wind turbine life cycle – with an emphasis on upgrading existing projects and equipment.
Working in close partnership with original equipment manufacturers (OEMs), Altra Motion develops its products, components and assemblies to suit designs and specific requirements from the initial prototype phase.
Products include the Yaw Brake Lifting and Installation Tool, which enables the easy interchange of yaw brakes in-situ; and the portable Disc Resurfacing Tool, which allows for uptower operations to be carried out on-site with increased speed while not compromising the refurbishment.
When it comes to reducing yaw brake noise, Altra Motion’s Groove Tool cuts grooves in the yaw brake disc, acting like a razor as the turbine moves to meet the wind, cutting detritus from the brake pad. A brush located between brakes removes debris from the grooves, allowing the disc to clean itself, helping to safeguard braking performance. This solution is adapted to meet the specific needs of any given turbine.
Specially developed in-house by Svendborg Brakes to develop an environmentally-friendly brake pad material, Altra Motion has created the Green Alternative Yaw Brake Friction Material.
This product meets the restriction of the use of hazardous substances (REACH) standards adhered to by the automotive industry, ensuring that the environmental impact and risks to maintenance personnel from yaw brake dust are greatly reduced.
In addition to its uniquely developed products, Altra Motion also ensures timely, responsive maintenance support via its 24/7, 365 days-a-year dedicated service app and phone number.
Maintenance engineers around the world can message or call experts at any time to get access to key technical information and guidance for critical repairs, allowing Altra Motion to react quickly, leveraging innovative aftermarket service tools and solutions to solve issues fast.
This sponsored editorial was brought to you by Altra Motion. For more information, visit: www.altramotionaustralia.com.
