Gloves for wind turbine blades in Alaska

28 June 2018

The island Kodiak in Alaska is famous for its big brown bears and wild nature.

Nature plays a specifically important role in the habitants’ life on the island. More than 98 percent of the total energy production comes from hydro and wind energy. Since 2007, the local energy company, Kodiak Electric Association, has converted the island’s isolated micro-electricity network , making it almost self-sufficient in terms of sustainable energy.

Around 20 percent of the island’s electricity is produced by six 1,5 MW wind turbines placed on the mountain top of Pillar Mountain, which is located close to the island’s biggest city, Kodiak, where a strong wind blows most of the year.

‘’Naturally, the weather plays a significant role here in Alaska. We have frequent rainfall all year round, lots of ice and snow during winter and of course strong wind. Due to the harsh weather conditions, constant erosion of the leading edges of the turbine blades has been the biggest problem since Pillar Mountain Wind Turbine Project was initiated in 2009’’, said Executive Director, Darron Scott, from Kodiak Electric Association.

Erosion of the leading edges of the turbine blades reduces the productivity of the turbines and the life of the blades.

Danish-developed technology protects the edge of the turbine blades
Kodiak Electric Association has persistently tried to solve the problem, but so far, the tested solutions and materials have not been able to withstand the sustained impacts of the aggressive environment.

Now, Kodiak Electric Association have finally found a solution that works by using soft shells made of polyurethane developed by the Danish company PolyTech.

‘’By the time we heard about PolyTech’s solution, we were running out of options. We tried the solution on three of our wind turbines, and so far it has been successful. The leading edge protection has been installed during the winter and has not been damaged, so we are very excited and have decided to install PolyTech’s solution on the remaining wind turbines in Kodiak’’, said Darren Scott.

The solution called ‘Ever Lasting Leading Edge’ (Elle)is installed on the tip of the leading edges of the turbine blades. Here, they function as a hard-wearing, shock-absorbing protective layer, which absorbs the kinetic energy from the drops of water, ice particles and bugs that causes the erosion damages.

Leading edge protection should be installed at the factory
An employee from PolyTech recently visited Alaska where he assisted the employees from Kodiak Electric Association in installing the leading edge protection on the remaining wind turbines. Ideally, the leading edge protection should have been installed during manufacturing, but the wind turbine manufacturers have lacked the necessary technology.

‘’Until recently, there have not been any good products on the market, which is the reason why many of today’s wind turbines are exposed to erosion on the leading edge of the blade. ‘Elle’ can be installed on existing turbines during all temperatures and wind conditions – where employees are permitted to work on the turbine. We offer our customers training in installing the solution’’, said executive director Mads Kirkegaard and continued:

‘’However, it is without a doubt much more cost efficient to install the leading edge protection while manufacturing new turbine blades. The cost increases with a factor of 100, when the work is moved from the turbine factory to the service engineer hanging in a rope attached to an offshore wind turbine’’, said Mads Kirkegaard.

Every week, PolyTech delivers soft shells to around 150 wind turbines – both for new blades, but also, as in Alaska, for mounting on existing turbine blades.

Source: Energy Supply DK