At 51.5 metres, the new blades are one metre longer than the Aerpac rotor. "The Polymarin rotor design has also been optimised for this length whereas the APX 48 blade was extended," says Lagerwey's Remco Boersma. All new LW 52 turbines destined for medium wind sites will be fitted with the new Polymarin blades as standard.
The rotors on the Andermatt turbine, however, where winter temperatures can drop to minus 25-35C, are also equipped with a special electrical heating system, as is the nacelle. "We'll be monitoring its performance very closely," says Boersma. "This is the coldest we've gone and we want to increase our expertise in the areas of "winterisation," blade heating and de-icing in order to keep pace with a market which is moving from the traditional coastal areas to more extreme sites. There is definitely a link between this project and to the projects we are anticipating in North America."
The heating system has been jointly designed by Lagerwey and Polymarin, which is based in Medemblik. The customer is local Swiss utility EWU. Annual production from the turbine is expected to be around 2000 MWh.