A theroretical need of about 30 helicopters to bring equipment and mechanics to the mills is not a small market i think.
I've been out to the wind mill farm in its construction phase off the Dutch coast, each one has a landing area for boats and a ladder up the wind mill mast for access to the top.
They were assembled by a crane atop a jackup barge, that lowered legs to the sea bottom so it was stable. So it is very desirable to install wind mills in shallow water as assembly is very fast and reliable.
Why would helicopters need to be involved in the wind farm to which you refer?
Mickjoebill