WIND ENERGY SYSTEMS - Cd3wd

Chapter 1—Introduction 1–14
Figure 5: Sandia Laboratories 17-m Darrieus, rated at 60 kW in a 12.5-m/s wind. (Courtesy
of Aluminum Company of America.)
The first large Darrieus constructed was a 230-kW machine on Magdalen Island, Quebec,
Canada in May, 1977 by Dominion Aluminium Fabricators, Limited of Ontario, Canada. The
average power output of this machine was 100 kW over the first year of operation, which
is quite good. Then a noise was observed in the gearbox so the machine was stopped for
inspection and repairs. During the inspection process, the brakes were removed, which should
have been safe because the turbine was not supposed to be able to self start. Unfortunately,
on July 6, 1978, the turbine started, and without a load or any way of stopping it, went
well over the design speed of 38 r/min. The spoilers did not activate properly,and when the
turbine reached 68 r/min a guy wire broke, letting the turbine crash to the ground. Perhaps
the main lesson learned from this accident was that the Darrieus will sometimes start under
unusual gust conditions and that braking systems need to be designed with this fact in mind.
A major design effort on Darrieus turbines has been made by Alcoa. They first designed
Wind Energy Systems by Dr. Gary L. Johnson November 20, 2001