I'm reading this to mean that it is possible to (a great extent-80%+) run a (high speed) rail network with one of these every two and a half kilometres.

I assume this only applies in non-built up areas, but have I got this about right--Europe (or anywhere) could plant these windmills every two or three km along its rail tracks and have a large part of its rail infastructure powered by wind?

Don't fight forces, use them R. Buckminster Fuller.