Dr.A.Jagadeesh Nellore in his comment says the only big turbine that was successful was Tvindmill(2 MW) in Denmark. He thereby ignores several large semi-commercial and commercial 5 - 7.5MW turbine models, introduced since 2002. These include the 4.5 - 6MW Enercon E-112, the 6 - 7.5MW Enercon E-126, the 5MW AREVA Multibrid M5000, the 5MW REpower 5M and 6.15MW REpower 6M, 5MW BARD 5.0, and 4.5MW Gamesa G128-4.5MW and G136-4.5MW.
Dear Dr.A.Jagadeesh Nellore,
I am rather familiar with historic wind turbine history including the turbines mentioned by you, including the MOD, Growian and Tvind.
My comment focused on your statements in the lower lines of your contribution. You wrote for instance: 'The 7 MW Vestas V164 turbine has more than double the capacity of the biggest offshore machines today, which are 3 MW.'
Unfortunately the above statement is factually incorrect. REpower operates for instance already 44 of its 5MW 5M turbines offshore, and a few weeks ago the first 6.15MW 6M successor offshore model was successfully installed off the Belgian coast. AREVA Multibrid further operates six of its 5MW M5000 turbines offshore and will add more this year. BARD has at least around twenty turbines grid connected offshore.
Principles of the direct drive principle versus geared drive will be explained in detail in the upcoming 'in-depth' report on the new Siemens Concept wind turbine design.
Eize de Vries