Stephen Mraz
Senior Editor
No question there is a case to be made for drawing
electrical power from the wind. Power utilities say
they're eager to generate electricity using a clean fuel
with little environmental impact, and they have customers lined up and waiting. Turbine and blade manufacturers, most based in Europe, are also eager for
the opportunity to serve 300 million U.S. consumers.
But most important, the U.S. government is
greasing the skids for wind power, making all this
possible with healthy subsidies and mandates
that power companies adjust generation portfolios so about 15% comes from "alternative" energy sources. Wind-power proponents say it would be
feasible for the U.S. to get 20% of its power from
wind by 2020. The current figure is only 0.8%.
But this hardly means we should throw caution
to the wind.
ONLY WHEN THE WIND BLOWS
Needless to say, wind turbines only generate
electricity when the wind is blowing. This translates
into an average output equaling roughly 30% of total
rated capacity. Thus for customers such as hospitals and Internet companies who need uninterrupted service, every megawatt of power created by a
wind turbine must be backed
up by an equal amount of
power from more reliable
sources, such as a nuclear
or coal-burning plant. But
it is inefficient to run power
plants at less than 50% of capacity. So wind power may
make most sense as a means
of avoiding brownouts rather
than as a competitor for conventional power facilities.
Researchers have also proposed several ways to overcome wind's intermittence.
Most involve storing windgenerated energy either by
cracking water into hydrogen
or pumping water into reservoirs, reclaiming potential energy as water passes through
a hydroelectric dam. Other
schemes involve charging
batteries. One of the more
ambitious ideas is to carefully monitor utility-power
demand and real-time wind
conditions, then balance the
two by bringing turbines on
and off the power grid. And
even this might not be possible without new, more efficient transmission lines.
BUYING WINDMILLS
Most windmill manufacturers are European and the euro is currently at
record highs against the dollar. So it's pricey to
import wind-turbine capital equipment like 50-m
pylons, 30-m blades, and large generators. Some
wind-industry experts predict prices will continue
to climb by about 1.5% annually. Economists see
this as potentially good news for the U.S., believing
it will spur development of homegrown wind-turbine companies. They estimate that a continuing
interest in wind power could create 3.7 million jobs.
There's also debate among wind-industry leaders
about the best way to site wind farms. Where wind condition are best, demand tends to be weak. And
close to urban centers, wind conditions aren't always
that great. Of course, breakthroughs in transmission
or energy storage could render such questions moot.
KEEPING IT GREEN
The biggest factor in wind power's favor is its portrayal as a 100% clean source of renewable energy.
But wind has its detractors. Some upscale residents of
Martha's Vineyard and Cape Cod, Mass., for example,
oppose a wind farm there. The Cape Wind project
would consist of 130 spinning wind turbines covering
25 square miles. Though the site would be more than
6 miles from shore, residents fear it would spoil the
scenery and kill fish and birds. The environmental
activists group Greenpeace, however, insists that offshore windmills pose no threat to marine or avian life.
Those living near wind turbines sometimes complain about the noise the spinning blades create. They
say it's unbearably loud, almost like a jet airplane.
But wind-turbine makers say the noise issue is all
but resolved. Newer blade technologies limit noise,
and zoning ordinances can be written to regulate it.
Finally, there is the issue of energy use. Though
wind turbines don't consume fuel, it takes at least
150,000 lb of steel, concrete, and fiberglass to build
a single 3-MW turbine. Thus, turbines have a carbon
footprint that is laid down before they ever generate a single kilowatt. And detractors point out that
steel and concrete are both energy intensive, carbon-emitting industries. There are also networks
of roads needed to service wind farms. And wind
turbines take land, somewhere between 60 and
300 acres/MW. (For comparison, nuclear and
coal plants generate about 1,000 MW/acre).
There are several European countries with significant wind-power experience. They offer lessons about
what works and what doesn't. For example, Denmark
is the country getting the largest percentage of its electricity from wind turbines. But Danes also pay more
for electricity than anyone else. The average Dane
pays 34¢/kw-hr, according to Eurostat, the statistical
office of the EU. In the U.S., that rate varies from 5¢
(Ohio) to 15¢ (Calif.) per kw-hr. And if today's warnings
over global warming eventually turn out to be false
alarms, the limits on economic growth imposed by
higher electrical costs may seem like a bad bargain.
MAKE CONTACT
American wind Energy Assoc., www.awea.org