Ice Shedding

Wind turbines can experience periods when the weather conditions will result in ice build-up on the exposed parts of the turbine. In addition, it has been observed that the moving turbine rotor is liable to accrete heavier quantities of ice than the stationary components of the wind turbine. It has also been observed that the rotor ice can break off, and if the rotor is moving, be cast some distance.

Field observations indicate that most ice shedding occurs as temperatures rise and ice thaws from the rotor. A typical scenario is that ice builds up on the rotor and on the wind sensors, which are mounted on the nacelle. Sensor malfunction normally causes automatic turbine shutdown in most modern wind turbines. In this situation, most turbines will restart only when the ice has thawed and fallen from the stationary turbine and the operator has reset the sensors. However, in certain situations the operator will accelerate the process by thawing the sensors and restarting the turbine with ice still on the rotor. This may lead to shedding of ice. Operations staff is more likely to be affected than the public.

Studies have been conducted to try to characterize how ice fragments are shed from the rotor blades. While limited information is available, evidence does suggest that there is a tendency for ice fragments to be dropped off, rather than thrown off, the rotor. Also, ice tends to shed more from the blade tips, and larger pieces of ice debris tend to fragment in flight.

Public health and safety risks and associated mitigation techniques may be incorporated into an overall emergency action plan to be used throughout construction and operation by project personnel in coordination with local emergency management officials.

5.8.1.1 Mitigation

Key steps to reduce the risk to the public or operational staff of injury due to ice shedding are provided. This should also be detailed in the facility's emergency action plan.

Possible Mitigation Measures to Reduce Threat of Personal Injury from Ice

S Design of turbine layout with appropriate setbacks from sensitive receptors and areas of regular public use to minimize risk of ice shedding injury.

S Education of operational staff about the conditions likely to lead to ice accretion on the turbine, the risk of ice falling from the rotor, and the areas of risk.

S Use of warning signs alerting anyone in the area of risk.

S Implementation of special turbine features that prevent ice accretion or operation during periods of ice accretion.

S Curtailment of operation of turbines during periods of severe ice accretion.

Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

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Responses

  • florian
    What does shedding wind mean on a turbine?
    7 years ago

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