A few hours after one of its wind turbines threw a blade in the Imperial County desert town of Ocotillo, builder Siemens Energy announced it is shutting down all its turbines worldwide that use the same blade until their safety can be assessed.
The faulty wind turbine at Pattern Energy's Ocotillo Express Wind facility threw a ten-ton blade late Wednesday night or early Thursday. No one was injured, despite the blade's coming to rest atop a Jeep trail on public lands approximately 150 yards from the turbine.
In a statement provided to ReWire, Siemens Energy said it would be "curtailing" -- slowing or shutting down -- all its turbines that use the blade in question:
A B53 rotor blade of a SWT-2.3-108 wind turbine broke off near the blade root and fell to the ground at the Ocotillo Wind project in California. No one was injured.
Siemens Energy has immediately convened a team of experts at the site who will examine all facets of this incident, including the production, installation, commissioning and service of the blade, which is under warranty by Siemens Energy.
Siemens does not yet know the root cause of this incident and is working to determine if and how this is related to a recent similar incident in Iowa.
Today, Siemens is taking the step of curtailing all turbines with the B53 blade type globally. These turbines will remain curtailed until it can be determined they are not at risk of a similar malfunction.
The Iowa incident took place in April at MidAmerican Holdings' 200-megawatt Eclipse wind farm.
Siemens didn't mention how many turbines would be affected by the shutdown. If it lasts for very long that spells trouble for facility owners, who depend on functioning turbines for their income. Ocotillo resident Parke Ewing, a neighbor of the facility, noted that Siemens staff had been working to cover the thrown blade with tarps all day Thursday. "We wonder if the variable winds in this area had anything to do with the incident, maybe causing extra stress on blade attachments," Ewing told ReWire. "Winds on the ground [Wednesday] night were only 19 mph. The turbines should be able to withstand 130 mph winds."