Icy weather conditions impede wind turbine service reliability, as ice easily forms on the rotor blades. The phenomenon is especially familiar in northern regions, like Sweden and Finland.
Ice formation leads to production losses and the risk of ice throws, in which pieces of ice could come loose from the turbine. Over the past winter, a few such ice throws occurred at wind power plants operated by Vattenfall, though none of them caused any injuries or damage.
Data from ice
A study analysing measured icing and comparing the figures to model data started in 2010. This study is now being followed up by an analysis of production data and ice problems on othersites in northern Sweden. The study is based on data from ice measurements and data from metrological models.
The project will also investigate available mitigation technology, various solutions and their costs. This will be done in cooperation with turbine producers. “In all phases of the project we measure, analyse, and evaluate various solutions, but each phase carries us further in understanding and acting on the problem,” says project leader Daniel Gustafsson.
The usual approach to de-icing is to install heating in the rotor blades. That is not enough to eliminate the production loss entirely or to completely eliminate the risk of ice throws, but it does decrease the risk. Other measures may include replacing sensors, adding new sensors and mounting of cameras.
The project will be completed by the end of June 2012, with further data being recorded over the coming winter.’