Emergya's Gerry van der Sluys believes DirectWind technology was chosen from the six bids received by Delta because, "it is direct drive, no gearbox is necessary, which means that a lot of wear and tear caused by gears is prevented." Gearboxes, he says, are a major cause of noise and the Delta project ran into problems with this issue, dropping the originally selected turbines after a court hearing.
The DirectWind turbines are especially suited to turbulent winds and can be adapted for operation in light winds, as at the Anna Maria site where they start to generate electricity at wind speeds of just 2.5 metres per second, says Van der Sluys. "We want to focus on wind plants where access is limited and where the grid is weaker."
Emergya Wind Technologies of Schoon-dijke, which bought the intellectual property rights of bankrupt Lagerwey Windturbine, was formed in 2004. It launched the Direct-Wind 900 in mid-2005. The firm has further developed the product range and built on Lagerwey's know-how, says Van der Sluys. "We have changed and adapted the technology, enriching it, which makes manufacturing possible on a larger scale."
First large scale
The Delta Energy order is the first large scale one for the 900 kW machine, but Van der Sluys says Emergya hopes to close other large deals soon in the US, Canada, Turkey and China. He describes Emergya as an integrator: it owns long time wind turbine blade manufacturer Polymarin Composites in Medemblik. It is also the owner of an "important range of patents for offshore turbines" of 5 MW and 10 MW, he adds. Although two years away from market introduction, the offshore turbines are being developed with other companies, says Van der Sluys.
Lagerwey was best known for its small two-blade wind turbines, hundreds of which were sold to families in the 1980s and 1990s and are dotted across the Dutch and German landscapes. It failed to make a successful transformation to utility scale projects with its next generation of direct drive technology, a 2 MW version of which was later marketed under the Zephyros brand name before it passed into the hands of a Dutch division of Japanese Harakosan (Windpower Monthly, November 2005).