Wind turbines and public safety: Setbacks Matter

Last month, the LA Times examined how the push to build more wind and solar installations was raising safety concerns for workers and the general public. As if on cue, local newspapers around the U.S. also ran stories on five separate catastrophic events involving turbines: a shattered blade in Ohio, fires in Texas and Michigan, the death of a technician in Iowa and another hospitalized in Kansas. None of these stories made national news so most people have no idea the frequency of such events.

Wyoming turbine collapse

Large-scale wind turbines operating in the U.S. are typically located in remote areas away from where people gather. Should a turbine fail the risk of bodily harm is low. But as more communities respond to government incentives and work to erect their own towers on town-owned land we're finding a dangerous pattern of authorities approving proposals with little consideration, or apparent understanding, of the safety risks.

Setbacks matter

The story of mounting safety concerns is not new. A report from 2007 found that as wind turbines multiplied around the globe, the number of dangerous accidents was also climbing. The authors cited problems ranging from defects in design and manufacturing processes to construction errors and harsh operating environments. Thousands of insurance claims filed in 2006 alone led some to question whether wind turbines were as reliable or as safe as developers purported.

According to Warren Diogo of Ascot Underwriting, the onshore wind sector is undergoing "rapid evolution". Turbine components are being modified and scaled-up quickly to meet changing market demands and challenging site conditions. The period between research and market launch is greatly reduced leaving little time for testing prototypes before they're placed in the field.

The industry insists that even if a failure does occur, safety setbacks lessen the likelihood of anyone being harmed. That's true, but there's no consensus regarding setback standards. Each time a project is proposed, the same arguments are raised over how close is too close.

Safety vs. statistical probabilities  

Advancing the notion that these massive spinning structures can be safely erected a few hundred feet from property lines, public areas and rights-of-way sends a dangerous message to the public. Blade failures, fire, and turbine collapse are more common than many have been led to believe. Communities should not be lulled into a false sense of safety. And when turbine failures are reported, they should take notice and not assume any failure is a singular event that won't repeat in their town.

Safety cannot take a back seat to statistical probabilities but that's what's happening especially in densely populated communities where land is scarce.

The latest example, and perhaps one of the most egregious we've looked at, involves a proposal to erect a General Electric 1.5 megawatt turbine in Salem, Massachusetts. The city's mayor is recommending a 382-foot tower be sited at a public park on Winter Island, adjacent to several historic buildings, the harbor master's office, and 300-feet from abutting property lines.

A turbine on Winter Island?

The Salem proposal exposes how ambiguous the question of turbine safety has become.

When asked what land would be removed from public access to accommodate the tower, the city's answer implied no safety buffer at all: 

The diameter of the monopole (tower) for the proposed Winter Island turbine will be about 15 feet (180 sq ft).

On the question of catastrophic failure, the response was equally unsettling:

Modern wind turbines are fitted with ice monitoring technologies that sense ice buildup and "turn off" ...In a study that looked at a 31 year period ending in 2006, among thousands of installations worldwide, there were no injuries or deaths attributable to wind turbine blade throw, either among the general public or wind industry workers. Typically it would take something in excess of a Category 5 hurricane to blow one of the units over.

Salem's mayor appears to be accepting everything the industry claims in order to sell the wind turbine project. Unfortunately, safeguards don't work as well as advertised. Footage on the web clearly shows turbines spinning with ice caked on the blades. Also, hidden damage to turbine components can lead to failures long after the events which caused them. Turbines may appear to be in good operating order and then fail unexpectedly. Three separate collapses occurred in the northeast since 2008 and none involved category 5 hurricanes.

It's not clear whether G.E. will even agree to erect one of its turbines on Winter Island.

Recall last year when Falmouth and Charlestown in Massachusetts approached the company about supplying turbines. G.E. refused citing inadequate setbacks for mitigating the risk of ice shed. To meet the same standard, the Salem project would need to be setback 775+ feet from occupied structures, roads, property lines and public access areas. The city would be wise not to ignore this setback.

Salem has been poorly served by the experts it consulted. We recommend the project, as defined, be cancelled immediately and call on the industry to bring more clarity to the setback debate. Erecting this enormous wind turbine in a public park so close to a neighborhood is nothing more than a recipe for disaster.

(Note: The distances referenced in this editorial pertain to the risks of flying debris from operating turbines. Setbacks to mitigate for turbine noise, shadow flicker and visual impacts -- which would be much larger -- are not considered.)

SEP 22 2011
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