Did icing damage the Screggagh rotor head?

Posted: January 4, 2015 by tchannon in weather, wind

Roger asked about wind conditions, “I’d like to see the output from the site anenometer so we knew what windspeeds were up there when it went down.” … can’t do that but I can dig…

Bing aerial images of wind farm

A question arises on whether the rotor assembly was damaged during icing conditions, later failing under relatively simple conditions. Water ingress into composite blades is also possible.

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SNOW, dated 11th December 2014 at a Met Office site not far away. The Met Office communications failed, quite common with Met Office sites. The wind at the 300 metre ground altitude Screggagh wind farm will have been faster, more so at hub height. Other met sites had snow and rain, wet conditions with a wind.

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The earlier snow event was before some rain followed by a hard freeze then the wind storm where the machine failed.

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Wind gust, note the wind speed scales are different. These are nothing dramatic, well exceeded earlier during the year. (not shown here) A minor low pressure area cross the region around 17 to 18 hours just before the failure, with minor evidence of wind shift, nothing dramatic. (not shown here) Icing

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Graphic from Nordex (the manufacturers) PDF about anti-icing designs. I suggest it is not so much cold as wet cold.
http://www.nordex-online.com/fileadmin/MEDIA/Produktinfos/EN/Nordex_Anti-Icing_en.pdf
Promotional PDF about icing
http://www.nordvind.org/files/otherfiles/0000/0084/Current_issues_on_wind_energy_production_in_cold_climate_-_Wallenius.pdf

This web site will raise some smiles over photos and content
http://www.windbyte.co.uk/safety.html

Other matters

Fintona celebrates £1 million windfall FINTONA is celebrating news that the area is to receive a £1 million windfall which will be spread over the next 25 years. The Fintona Community investment fund is being provided by the owners of the relatively small eight turbine Screggagh wind farm, built in 2010-11, which is located in the townland of the same name just outside Fintona. The investment will be £40,000 per annum, (£5,000 per turbine), index linked to keep in line with inflation for a minimum of 25 years or the lifetime of the wind farm, and result in a minimum of £1 million investment at today’s value in local community initiatives.
http://ulsterherald.com/2012/12/08/fintona-celebrates-1-million-windfall/

Post by Tim

Comments
  1. Joe Public says:

    “The investment will be £40,000 per annum, (£5,000 per turbine), ….”

    No doubt lawyers from both sides are rubbing their hands with glee at the prospect of deciding if the contract states the former, or, the latter.

  2. Centinel2012 says:

    Reblogged this on Centinel2012 and commented:
    Maybe we should no be building any wind turbines that are much better ways to generate power.

  3. michael hart says:

    I guess “The Bride of Lammermoor” is now not the only tragedy set there.

  4. michael hart says:

    ….that is, at the Crystal Rig windfarm mentioned at the site Tim links to.

  5. Graeme No.3 says:

    Polyester Composites will absorb water slowly. This is well known to the sailing boat racers who like to take their boats out of the water after a race, to dry the boat and reduce the added weight. It may only be 1% extra but it slows the boat.

    Wind turbine blades are basically the same construction as fibreglass boats, so they could absorb water, although it would take a longish period of very wet weather, so I think that is unlikely to be the cause, as all blades would be affected. To check they could simply weigh a blade section and again after drying.

    Remember that the blades are hollow. Damage to the blade surface e.g. by ice, might have allowed water to get inside the airfoil part and unbalance the blade.

  6. oldbrew says:

    BBC: ‘People in the area said the rotor blades were spinning out of control on the evening the turbine buckled.’

    Link says: ‘Wind turbine control is essential for optimal performance, safe operation, and structural stability.

    http://www.ni.com/white-paper/8189/en/#toc2

  7. steverichards1984 says:

    Perhaps it lost its connection to the grid and its backup diesel generator did not start causing control to be lost. So no brakes, no load, no pitch control leading to fatal high speed revolutions causing structural failure.

    I wonder how robust the safe case is for each design aspect of these devices is?

  8. oldbrew says:

    ‘System fault led to Screggagh wind turbine collapse’

    “Nordex has concluded its interim investigation and confirmed that this was a unique fault concerning the wind turbine blade control system,” Doreen Walker, director of the wind farm, said.

    http://eandt.theiet.org/news/2015/feb/turbine-collapse-cause.cfm?origin=EtOtherNews