In the beginning there were high hopes and a great sense of adventure. Customers lined up to buy wind turbines without really knowing what it was like to operate and maintain them in cold climates.
Manufacturers weren’t that much wiser; in some cases they had to send people up the turbines to hack ice off the blades.
Pretty soon reality hit the pioneers: ice, and plenty of it, accumulated rapidly on the blades and, as wind turbines grew larger, it proved difficult to remove.
In the 90’s,VTT worked with Bonus to design blade surface heating foils. Some 20 wind turbines, ranging in size from 150 kW to 1 MW, were equipped with these systems. One of the two systems installed in Sweden is still in operation more than 15 years later.
Enercon introduced its ice detection and hot air based de-icing system in 2004. At Winterwind 2012, Enercon presented potential net energy production gains of up to 25% with their latest de-icing system.
These systems, and others that have followed, have had a significant impact on production in cold climates, but there’s still no quick fix for ice. Investors are now requesting performance guarantees with respect to icing, which no WT manufacturer currently offers.
De-icing systems can keep ice away, but their performance varies greatly depending on the technology used and the location of the wind turbine.
The lack of performance guarantees for operation in icing conditions means investment risk, and no investor likes unquantifiable risk.
Owners are now demanding warranties from the manufacturers. It is, of course, hard for Enercon, Vestas, Siemens, Nordex, Gamesa and the other companies to guarantee a specific performance in such very diverse – and unpredictable – conditions. Icing can be a persistent and yet rapidly fluctuating problem.
But what we are talking about here is risk sharing for a significant part of the market in a fast growing industry.
Owners already absorb a lot of risk related to permits, public opinion, noise reduction and environmental issues. Performance warranties must be a joint project, shared across the whole industry.
Apart from warranties we also need independent validation of de-icing and anti-icing systems within research projects and the development of intelligent turbine control systems for de-icing systems.
From being a small niche market, cold-climate projects today make up 25% of the world wind market, according to consultants BTM.
The heyday of “let’s try that!” is over. We’re world leaders now. So let’s show the world what we can do together!
Chairman Swedish Wind Power Association