EDE, Netherlands -- In this small town whose old wooden mill
generates more tourism than energy, a shiny new stainless-steel
windmill on the roof of a technical school barely whispers as its
blades spin in a brisk winter breeze.
Such high-tech turbines, which feed kilowatts to local power
grids, are now poised to conquer a new frontier -- the modern city
center. Often fused into building designs, the mills are barely
noticeable from a distance.
They are lighter, quieter and often more efficient than their
lumbering rural counterparts; and they're built to take advantage of
the extreme turbulence and rapid shifts in direction that
characterize urban wind patterns.
Germany, Finland and Denmark have also been experimenting with
the technology, but the ever-practical Dutch are natural pioneers in
urban wind power, ''mainly because of the lack of space here,'' said
Sander Mertens, a wind energy researcher at the Delft University of
Technology.
Dutch cities including Amsterdam, the Hague, Tilburg and Twente
plan to install urban windmills in 2003, mostly small-scale projects
with fewer than a dozen turbines each.
SYMBOLIC MOVE
''First we want to see how it works out,'' said Andre Struker of
Amsterdam's environmental department. ``It's still a bit symbolic, a
way of bringing wind energy closer to the people.''
The prospect of a new, environmentally correct energy source has
attracted Dutch energy companies. Cor De Ruiter, a spokesman for one
company, Eneco, said research has indicated there are 50,000
locations in the Netherlands where small urban turbines could be
installed.
The new windmills pay for themselves in about five years,
according to the Dutch manufacturer Prowin. And as the technology
improves, prices will drop further. The smallest models weigh
roughly 440 pounds and can be installed on a roof in a few
hours.
''All the technical problems are behind us now,'' says Dick
Sidler, an engineer at Core International, another company that
builds the latest-generation turbines.
Current models cost $5,000 to $12,000. The windmill on the roof
of the technical school in Ede can generate about 5,000 kilowatt
hours of energy per year, which would cost $900 if taken from the
fossil-fuel-powered grid.
That's more than enough for the average Dutch household, which
consumes roughly 3,500 kilowatt hours per year -- the average
American family uses 10,000 -- although most new windmills are
designed more for public or commercial buildings than for private
homes.
The Netherlands, with 16 million people crowded into an area
twice the size of New Jersey, is the most densely populated country
in Europe. It generates less than 1 percent of its electricity from
wind. In Denmark that figure is 18 percent; Germany 4 percent; in
the United States a fraction of 1 percent.
But Holland has on average 245 days per year with wind speeds of
13 to 19 mph, which can power even the biggest turbines. Many of the
new urban turbines can begin spinning with wind speeds as low as 5
mph.
MORE EFFICIENT
With fewer moving parts than their rural kin, urban turbines
generally require less maintenance. And because the energy they
generate is close to where it is consumed, less electricity
dissipates while crossing transmission lines.
The urban turbine could also get a boost from European
initiatives to increase the viability of sustainable energy, leading
to heightened interest in ''zero-energy'' buildings that generate
their own power. A prototype building that accelerates the wind
through an integrated turbine was recently constructed in
Oxfordshire, England.
The recent liberalization of European energy markets now allows
customers to choose what kind of sustainable energy they buy, with
wind energy among the most popular.
Problems remain, however: notably public safety concerns.
''Just one accident would be enough'' to quash enthusiasm for the
idea, said Mertens, the researcher. One theoretical danger, runaway
windmill blades, could be averted by covering the turbines with
gratings, he said, but the effect of vibrations on local buildings
and inhabitants is still unknown.
So, might Manhattan or Chicago soon be dotted with spinning daisy
wheels?
SMALL STEPS
''I don't think it's reasonable to begin with the giant
skyscrapers yet. It would first have to be tested for safety and
efficiency,'' said Paul Schraven, a spokesman for manufacturer
Lagerwey. ``We don't know what it would be like to work there, in an
office next to one of the big turbines. It might be too
hectic.''
Meanwhile, other projects are underway to use the mini-mills for
lifeboats, streetlights and portable generators. Made of lightweight
fiberglass, many of these turbines consist of a helical, cylindrical
rotor, a design that largely eliminates the possibility of runaway
blades.
''I think the thing about wind power is that you can use it in a
whole range of situations,'' said Corin Millais of the European Wind
Energy Association. ``It's a very local technology, and you can use
it right in your backyard. I don't think anybody wants a nuclear
power plant in their
backyard.''