Rotary interface specialist BGB is reporting an increase in sales of silver carbon brushes, suggesting that the wind industry’s focus on copper alternatives may be a short-lived trend. Recent years have seen a concentration on cost reduction across the wind market. With the sector estimated to be worth $170B by 2024, it is becoming increasingly competitive, particularly with OEMs driving down prices.
Although costs will always be a factor, BGB’s sales surge suggests that the wind industry may now be switching its attention from reducing costs to efficiency and performance.
“In any market, decisions made by the market leaders tend to filter down to smaller companies too,” commented Chris Richards, sales and marketing director at BGB. “With larger firms starting to trial the use of copper brushes a couple of years ago, it’s no secret that the sale of silver carbon brushes declined.”
Brushes may be small but they are in integral part of a wind turbine, working in conjunction with slip rings and brush holders to protect components from parasitic currents and provide lightning protection for the turbine.
As Richards points out, knowing the difference between various brush types is vital: “We were finding that people were switching to copper brushes because of the lower price. However, you need to consider overall efficiency when it comes to calculating total cost savings.”
He says that silver carbon brushes last for about three to five years, while copper alternatives have a life expectancy of only one to two years. Test data shows that copper brushes are worn down by an average of 29mm per year, compared to just 16mm for silver versions. “Couple that with the fact that silver works more effectively in extreme climates and suffers significantly less oxidation, and you soon realize there’s a lot to weigh up other than basic costs,” he adds.
BGB has been providing engineering solutions for over 40 years and within the wind market since the early 1990’s. Via its manufacturing facilities in the UK and the USA, the company has helped bring energy to homes by powering over 65,000 wind turbines worldwide.
“The interesting thing is that the people who are enquiring about silver carbon brushes are the technicians themselves, who are reporting that continual maintenance is reducing efficiency and productivity. We anticipated that demand for silver carbon brushes may slowly start increasing again but we didn’t expect it to be as widespread as it has been,” said Richards.