Wind turbine typically lasts 20 years. But most wind turbine warranties cover only the first two to five years of a wind turbine’s life. As these systems age, not all facility owners are necessarily prepared to take on the task of maintaining their wind turbines. In some instances, there is a shortage of technicians to do the maintenance work. And even when a facility has the technicians it needs to perform routine repairs,unscheduled maintenance can put a noticeable dent in a facility owner’s bottom line.

One way that wind farm owners, engineers, technicians and makers of wind turbines can mitigate the risk of unscheduled repairs is to consider components that require less maintenance and even tell you when they’re going to fail. If that sounds like a far-fetched notion, it’s not.

Fiber brush slip rings are one such product. Although they are a relatively small part of the overall cost and design of a wind turbine, slip rings are critical to operation. Found inside the wind turbine’s nacelle, slip rings are commonly used to provide electrical signals and energy for blade pitch power and control. Slip rings transfer electrical power and signals across a rotary interface.

Here’s how slip rings work:

sliding contacts transmit electrical signals and energy across the rotating interface in a slip ring assembly. A brush, or wiper, slides on a rotating ring and maintains continual electrical contact during rotation. This means metal-tometal contact is required between the stationary brush and the rotating ring for error free electrical transmission. A fiber brush slip ring can offer wind turbine owners a minimum of 100 million revolutions of operational life with no maintenance, which means a technician might have to switch out the slip ring once during the turbine’s 20 years of life. But all slip rings are not created equal. In fact, it is important to understand the design and construction of slip ring assemblies to evaluate their maintenance requirements.