How a windfarm’s bottom line hinges on micrometers

Improper lubrication of wind turbines can cause tiny damages that may add up to significant economic consequences. Meet a leading lubrication expert from Castrol and learn how the company helps wind farms reduce downtime and lower their levelized cost of energy.

Modern wind turbines are technological marvels, some towering over 200 meters tall, with blades stretching more than 100 meters. However, their performance can be significantly compromised by tiny, 15-20 micrometer deep pits in the metal surfaces of their gears and bearings.

This phenomenon is known as micro-pitting. It appears as a frosted or gray appearance on the metal and is caused by surface fatigue within bearings and gearboxes. While the issue is well-known across various industries, it is particularly prevalent in machines with heavy loads, such as wind turbines.

Micro-pitting is one—but not the only—consequence of incorrect or insufficient lubrication. Other issues include overheating, sliding wear, fretting, false brinelling, pitting, and ultimately bearing seizure, and their impact is often all but micro, explains David DiNunzio, an STLE CLS certified lubrication expert at Castrol.

“All these issues reduce the operational efficiency of the drivetrain and thereby the wind turbine. With wind turbines being revenue-generating machines, a decline in performance will show up on the bottom line. What’s more, the longevity of the mechanical components is reduced, further impacting a wind turbine’s levelized cost of energy, or LCOE ,” says DiNunzio.

MicrofluxTrans Plastic Deformation

At Castrol, developing advanced lubricants for wind turbines has been a priority for more than 30 years. The company’s lubricants were used in some of the first American wind-energy projects in the 1980s, and today, new products are tested on Castrol’s own wind farms.

“Our products are designed to meet the specific needs of wind turbines,” explains DiNunzio. “They provide outstanding gear and bearing protection under high loads and low to moderate speeds, in any conditions.”

“This is essential, as wind turbines are under constant exposure to the elements in very different climates—from extreme heat to snow and ice, from humid to dry conditions, and with ever-changing wind speeds. What’s more, wind turbines are often serviced only once or twice a year, so the lubricants need to withstand long periods without degradation,” explains DiNunzio.

One of the secrets is Castrol’s proprietary MicrofluxTrans Plastic Deformation (MFT PD) technology.

“MFT PD creates a protective layer on metal surfaces, reducing micro-pitting and other failure modes while extending component life,” explains DiNunzio. It allows lubricants to deal with heavy vibrations and has been proven to reduce the coefficient of friction by up to 30% compared to standard greases and gear oils, helping to lower bearing and gearbox operating temperatures, reduce wear, and prevent micro-pitting.”

“Once a surface related failure mode occurs, damage typically progresses exponentially and ends in catastrophic failure of a component. MFT PD technology has demonstrated significant reduction of wear progression, up to almost arresting damage progression, on various pre-damaged surfaces in lab tests and in the field.”

Reliability is key

Using the right lubricant, however, is not enough, says DiNunzio. Correct administration of the lubricant is just as important—which is easier said than done.

“With most industrial machinery, you can walk out onto the shop floor, inspect components, take samples, and conduct failure analysis. You can’t easily do that with wind turbines, as they’re located 100 meters above ground or out at sea,” explains DiNunzio.

“As the wind-energy sector grows, wind farms are being built in more diverse locations, and wind turbines just keep getting bigger. This pushes us to continually improve lubricant technology, to ensure that wind turbines run reliably and efficiently, no matter where they are located.”

This ambition was a key motivator, as Castrol recently partnered with Hove to supply wind energy customers in Europe and the US with Castrol Tribol GR SW 460-1 and Tribol GR SW 680-1 lubricants in Hove cartridges, says DiNunzio.

“Hove have already transformed wind turbine maintenance and just made it much easier. We’re excited to join this new partnership to help wind farms become even more productive—no matter where they’re located.”

Read more about Hove’s solutions for wind farms here.