Monthly Archives: August 2010

Wind Turbines have steadily grown in size to the point where the largest models have blades of more than 100 meters in diameter.  The Gearbox (which connects the rotor shaft to the generator) continues to be the component whose failure results in the most significant cost and downtime.  Therefore, the reliability of the gearbox is one of the biggest concerns in the wind industry.  At present, wind turbines are generally designed for a 20-year design life; however today’s gearboxes generally have an operational life of  7-11 years, per Sandy Butterfield, former NREL Chief Wind Turbine Engineer. 

Some estimate that the current risk of failure of the gearboxes may have an economic impact as high as $300 Million USD.  Gearbox failures are so expensive because of the high cost of repairing or replacing the gearbox, and due to the resulting downtime associated with the replacement.  The gearbox itself typically represents about 10% of the total cost of the wind turbine system.  With downtime, transportation of the gearbox, and labor, typical gearbox replacement costs range from $300K-$775K USD.

With these very high costs, improved reliability of the gearbox can truly have a huge economic payoff.  It comes down to the need for accurately predicting the aerodynamic and inertial loads transferred from the huge composite blades over a wide range of operating systems.  In many cases flexibility of components such as shafts, bearings, gears, etc. can become very important.

For further background, see the article:
“Wind Turbine Gearbox Reliability”  at: 
or request a copy from me:

Find more on Green Reliability at the Ops A La Carte site.

3rd Annual PRG BBQ and Symposium
Click to register

Friday, August 20, 2010

8:00am to 3:00pm

Sheraton Sunnyvale Hotel
1100 North Mathilda Avenue
Sunnyvale, CA 94089
408-745-6000 Phone

Please join us for PRG’s 3rd Annual BBQ and Symposium. This is your opportunity to meet with industry peers, learn about the latest industry developments, and meet the PRG’s members in an informal setting while enjoying some delicious food.

The theme for this year’s event is “Hawaiian 2.0”!

This goal for this event is to create a forum for individuals and businesses involved in the Product Realization Process to gain knowledge, network, and have fun.

Ticket Price: $25
In the past this event has been free. This year we have moved from a park to a conference center and will be providing both a continental breakfast, and a full lunch plus a larger venue with presentations and an exhibition area. Please understand that charging for tickets is merely an effort to cover the cost of the food and the venue. We think this will provide a better environment for learning and networking for everyone in attendance. We hope to see you on August 20th!


Time Event
8:00am-9:30am Registration/Continental Breakfast – Sterling Ballroom
9:30am-10:20am Conference Session #1 – MedTech OR New Product Introduction (NPI)
10:30am-11:20am Conference Session #2 – CleanTech OR PRG Certificate Overview
11:30am-1:00pm BBQ – Garden and Deck Area
11:30am-2:30pm Exhibit Hours – Garden Area
2:30pm-3:00pm “Raffle” Announcements

For more details, go to: PRG BBQ