Ocotillo Wind Blade Separation


Pattern Energy broken blade

OCOTILLO – Last week a single rotor blade of a wind turbine in the northeast section of the Ocotillo Wind project separated from the turbine hub and fell to the ground with the nearest end of the blade approximately 150’ from the tower base. No one was injured.


Immediately after the incident all turbines at the project were shut-down as a precautionary measure.


Siemens convened a team of experts at the site to conduct a root cause analysis and to carry out inspection of all turbines in the project. The evaluation for the root cause analysis included field inspection of the blade on the ground as well as the blade root still connected to the hub. Siemens also reviewed its records involving the production, installation, commissioning, and service of this blade.


While Siemens has not yet fully concluded its investigation, it is now focusing its efforts on supplied root segments that appear to have separated from the fiberglass laminate of the main blade. Root segments are pre-cast inserts used to construct the blade root and are supplied to Siemens by a number of suppliers. As a result of the thorough analysis conducted so far, Siemens has confirmed that this issue is not related to the design of the blade.


The Siemens’ fleet of wind turbines has an excellent safety record and this type of blade failure is extremely unusual. Siemens has manufactured over 25,000 turbine blades using this root design for their fleet and the two recent incidents in Iowa and at the Ocotillo Wind project are the first time a failure of this nature has occurred.


Siemens is assessing every single blade at Ocotillo Wind to determine which blades may be impacted by this issue. For those blades that are affected, Siemens will perform all necessary repairs or replacements before returning the turbines to service.


We remain committed to ensuring the health and safety of the public as well as the protection of the environment. All turbines will remain off-line until their safety has been evaluated and confirmed.