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The number of cases involving collapsing turbines and flying blades (aka “component liberation”) has become so common that, if we were a tad cynical, we would go so far to suggest the possibility of some kind of pattern, along the lines proffered by Mr Bond’s nemesis, Goldfinger: “Once is happenstance. Twice is coincidence. Three times it’s enemy action”.

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Turbines have been crashing back to earth in frightening numbers – from Brazil – to Kansas – Pennsylvania – Germany and Scotland – Devon and everywhere in between: Ireland has been ‘luckier’ than most (see our posts here and here) and their luck is being enjoyed in Sweden too (see our posts here and here).

Then there’s the wild habit of these little ‘eco-friendlies’ unshackling their 10 tonne blades, and chucking them for miles in all directions – as seen in the video below – and see our posts here and here and here and hereand here.

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Fire (spontaneous combustion), wind and gravity have taken their toll on these things all over the Globe – with fatal results, snuffing out over 160 lives, so far; a fair bit sooner than the victims expected. For a breakdown on wind power fatalities: 290 Tonne Vestas Wind Turbines Dropping Like Giant Wounded Flies

Blade failure is the most common ‘accident’ on the wind industry’s list of death and destruction. For a taste of the chaos, let’s head to Spain

House hit by debris following blade failure
Windpower Monthly
Michael McGovern
5 January 2016

SPAIN: A house has been hit by pieces of a turbine blade that fell from a 300kW turbine in Spain following high winds, several local press are reporting.

Two 15-metre blades from the turbine disintegrated in the early morning of 3 January, striking an occupied house 280-metres away.

The blade failure occurred on one of 61 Desa A300 turbines at the 18.3MW Corme wind plant in the Ponteceso district of Spain’s northernmost province of Coruna.

The project is owned and operated by EDP Renovavais and has been online since 2000. Desa once belonged to Spanish turbine pioneer Abengoa and is now partly owned by EDP.

The owner of the house affected reported to local media that the turbine had been making “unbearable noises” for a few days before the incident, following high winds in the area.

On the eve of national holidays in Spain, EDP failed to comment to Windpower Monthly on the incident. But the company had issued a provisional statement to the local press saying it was “too early” to pinpoint the causes.

Its statement firmly denied that an explosion had occurred in the turbine, as reported by some local witnesses.

It also confirmed the turbine was operating at the time of the incident, as wind speeds at the time were within safe operational limits, at 90km/h (25m/s). Turbines had been halted in recent weeks due to higher winds, the statement said.
Windpower Monthly

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Now, if the 50m plus blades of giant industrial turbines were engaging in just the odd burst for component liberation neighbours’ anxiety levels might settle around the mild-edginess level.

However, those bunking down within less than 2km of these things can be forgiven for feeling a state of constant panic in the knowledge that close to 4,000 blades are busting free from their moorings every year.

In one serious scientific study into the distances blades are likely to travel during “component liberation” – covering over 37 “component liberation” events – blade throw distances of up to 1,600 m were recorded: that study was completed in 2007 – there have been many more bids for blade “freedom” since then (up to 2014 there have been 309 ‘incidents’, as detailed here).

In Australia, for “planning” purposes, the various states have a variety of “set-back” distances between wind turbines and residential homes – said (laughably) to avoid noise impacts: in South Australia it’s 1km.

For a few years the Victorians set it at 2km – but, before 2007 there was no set-back required and plenty of homes ended up with turbines within 600m. However, there is no such limit placed on the distance between roads and turbines.

So drivers, too, might be excused for being more than just a little nervous  – with whole (50m) blades travelling up to 200m, bigger heavier chunks likely to travel well over 300m and the smaller pieces (referred to in the study linked above as “10% blade fragments”) flying out to distances of up to 1,600m (for a 10% blade fragment – think 5m long blade chunks weighing a tonne or so) – and hundreds of turbines planted within 100m of roads at places like Cullerin, Waterloo and Macarthur.

And, from the reported numbers of blade ‘failures’, for very good reason.

Annual blade failures estimated at around 3,800
Windpower Monthly
Shaun Campbell
14 May 2015

WORLDWIDE: Wind turbine rotor blades are failing at a rate of around 3,800 a year, 0.54% of the 700,000 or so blades that are in operation worldwide.

The figures, from research carried out by renewable energy undewriter GCube, were delivered by Andrew Bellamy, former head of Areva’s 8MW blade programme, in his opening address to Windpower Monthly’s blade manufacturing and composites conference in London on 12 May.

Bellamy, co-founder of renewables advisory firm Aarufield, pointed out that blade failures are the primary cause of insurance claims in the US onshore market. They account for over 40% of claims, ahead of gearboxes (35%) and generators (10%).

The wind industry also faces a struggle to secure the carbon fibre materials it needs for lighter and stronger blade designs, warned Bellamy.

“There’s growing competition for these materials from the automotive and aerospace industries,” he said. “And they are willing, and able, to pay more than we are.”

Recent examples of blade failures include a blade from a Vestas V90 3MW turbine that snapped on a wind farm in the north of Denmark last year. At the time, Vestas said the winds were not particularly high.

In another case last year, GE was forced to replace 33 blade on its turbines at a Michigan wind farm after a blade broke on the project.

GE put the failure down to a “spar cap anomaly”. It was the second such incident involving the 1.6-100 model, and was followed by a third at the 94MW Orangeville wind farm in New York State, also in November.

Possibly the biggest blade issue was faced by Siemens in 2013 when it was forced to curtail around 700 turbines worldwide. This was caused by a bonding failure in its B53 blade.
Windpower Monthly

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Good to know that when these whirling Danish Dervishes were throwing their 10 tonne spears to all points of the compass when “wind speeds at the time were within safe operational limits”; and when “the winds were not particularly high”….

One can only wonder at the chaos and carnage when the wind really picks up. Although this video of one of Vesta’s ‘eco-friendlies’ letting loose gives a bit of a clue.

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