are windmills used to generate power in holland today? what is the
power used for/does it substitute for electricity or serve some other
very practical need?

Hello netherlands-ga,

Yes, Windmills are used today in Holland to generate power. However
more often than not, the windmills there are used to pump water.

"Take Holland, for example. Why is it called the land of windmills?
Because most of its land lies below sea level, and windmills are used
to pump water into canals from low-lying areas that are filled with
water. In the 17th century there were over 8,000 windmills in use in
Holland!"

There is a big push right now to build more windmill farms in Holland
to generate wind power and decrese the use of fossil fuels.

"If the proposed protocol on Greenhouse Gas emissions is ratified, the
Netherlands, like other developed countries, will be obliged to cut
back its use of fossil fuels and develop renewable energy resources.

For environmentalists, the windmill is a perfect alternative. The wind
never runs out, and leaves no waste products behind. "

http://www.pitara.com/discover/5wh/134.htm
http://news.bbc.co.uk/1/hi/world/europe/1021714.stm

Google Search:
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=windmill%20power%20in%20holland&btnG=Google+Search

I hope this helps,
Nenna-GA
Google Answers Reseacher

Yes, there is a lot of electricty generated by windmills in Holland,
as the first site below will show you.
The second site is that of a Danish opponents to wind-driven
generators, which will give the (not just their) arguments against.
The electricity is put into the power net like that from other generators.

The primary argument against wind generated power is that it in no way
reduces the necessity for power plants using oil, gas, coal or atomic
energy.  Yes, when the wind blows, it does allow a reduction in
electricity produced from these sources.  But when the wind does not
blow, the other sources must be immediately available.
 
Gas turbine generators, which can be started at short notice (for peak
period use), can be turned off, but the others have to be kept running
because their start up times are too great for them to be turned off
on a windy day.

http://home.wxs.nl/~windsh/english.html
http://www.juracretes.ch/default.asp?urlframe=%2Fcentre1%2Easp%3Fd2w%3D0%2D0%2D630%2D322%2D86%2D0