“uåX˜äŠÊ˜·³Ç

Removing the gearbox is not an easy solution (“uåX˜äŠÊ˜·³Ç, December 2005). What you achieve is to shift the problem from the gearbox to a huge generator. Just removing the gearbox does not increase wind turbine availability or reduce costs. We learned our lesson the other way around. A lot of drive train concepts are good, but they need time to come of age.

I am a victim of gearbox failure because my employer had to replace too many of them. Many employees had to leave the company, as a signal to shareholders. I was among them. If Mr Göken's remarks about the superiority of wind turbines without gearboxes were meant seriously, I find them impertinent. He says he is not connected to Enercon, so I would ask him to consider the following.

Back when I was still an employee of a wind company, the availability of wind turbines without gearboxes was extremely bad. Instead of the gearbox it was the generator that repeatedly caused problems (and costs). At the same time, the specific nacelle weight of these turbines lies significantly above average. Since much more copper is needed than usual, manufacture of these turbines is certainly not cheaper.

I have been working in wind turbine development for 20 years and today work as a development engineer for various turbine manufacturers on machines ranging from 10 kW to 5 MW. In my area of activity I work on gearless concepts, on compact-driven conventional gearboxes and hydraulic gears. All of these concepts have their own specific advantages.

I cannot identify an overwhelming advantage for gearless wind turbines.