Collapsing wind turbines

 Thomas Lifson:

Bloomberg Business Week, no foe of green energy, headlines: "Wind Turbines Taller Than the Statue of Liberty Are Falling Over."  The article beneath the headline reports on a variety of alarming disasters involving wind turbines, including collapses of very tall structures.

On a calm, sunny day last June, Mike Willey was feeding his cattle when he got a call from the local sheriff's dispatcher. A motorist had reported that one of the huge turbines at a nearby wind farm had collapsed in dramatic fashion. Willey, chief of the volunteer fire department in Ames, 90 miles northwest of Oklahoma City, set out to survey the scene.

The steel tower, which once stood hundreds of feet tall, was buckled in half, and the turbine blades, whose rotation took the machine higher than the Statue of Liberty, were splayed across the wheat field below. The turbine, made by General Electric Co., had been in operation less than a year. "It fell pretty much right on top of itself," Willey says.

Another GE turbine of the same model collapsed in Colorado a few days later. That wind farm's owner-operator, NextEra Energy Inc., later attributed it to a blade flaw and said it and GE had taken steps to prevent future mishaps. A spokesperson for GE declined to say what went wrong in both cases in a statement to Bloomberg.

The instances are part of a rash of recent wind turbine malfunctions across the US and Europe, ranging from failures of key components to full collapses.

The article blames the "rash" of incidents on the rush to install turbine capacity, but there are also permanent factors that make engineering, building, and maintaining wind farms difficult and risky.  To develop meaningful amounts of power, the blades on the turbine have to be big, and when big blades spin in heavy winds, the tips can end up hitting supersonic speeds, putting great stress on the materials used to construct them.  Big blades also requite tall towers, which are then subject to stresses as winds blow and can gust during storms to velocities that test the strength of the materials and the design of the towers.

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This appears to be an engineering problem that has not been solved as more of these towers are put into service.  Wind and solar energy require battery backups if fossil fuels are not used. The collapsing towers add another element of unreliability.