Re: Global Energy etc.

[Daniel Schroeder <DSCHROEDER@CC.WEBER.EDU>]

> > Don't complete write off wind energy--it seems to be becoming
> > much more economical than it once was.  Denmark already gets
> > 13% of its electricity from wind, and plans to increase that
> > to 50% by 2030.  Take a look at www.windpower.dk.
>
> Keep this in perspective.  Currently that is less than 2% of Denmark's total
> energy use.  Denmark's electrical usage is only 1% of the U.S. usage.  To
> get equivalent percentages of wind use here you need 100x the number of
> generators.  To use wind for sizable percentages of U.S. energy needs will
> require literally millions of fairly large (250-500 kW) generators.
>
> Rick

Rick, you and I have just demonstrated how the same facts can be distorted
in different ways to promote different points of view.  The only antidote
is more facts to provide context.  I just checked the EIA web site and
found 1998 energy data for Denmark.  For that year, wind energy (classified
as "geothermal and other") accounted for only 9% of Denmark's electrical
generation, .038 quads.  That represents 4.8% of its total energy
consumption, .798 quads.  However, in statistics like these one needs
to remember that wind-generated electricity, like hydroelectricity,
is conventionally multiplied by about a factor of 3 in order to make
a fair comparison with thermal generation which is only about 1/3
efficient.  In other words, the energy actually provided as electricity
by wind was only 1/3 of the number I just quoted, or .013 quads.
What you've apparently done is compared *this* number to the total
energy consumption, and then, indeed, you get less than 2%.  But
that's not fair because a coal- or nuclear-powered plant consumes
three times as much energy as the electricity provided.

But your point about Denmark being much smaller than the U.S. is
well taken.  U.S. electricity consumption is currently about 3.4
trillion kilowatt-hours per year (not counting waste heat at the
generators), which is about 84 times as much as Denmark's.  Therefore,
Denmark's current wind generation would provide only 0.15% of
the electricity currently used in the U.S. (and a still smaller
fraction of our total energy consumption).  However, we have more
of almost everything else than Denmark does.  In particular, we
have more money to buy turbines, more land to put them on, and more
wind to power them.  I don't know of any reason why their current
efforts couldn't be applied here on a larger scale.

How many turbines would it take?  Most of the turbines being made
now are in the 600-750 kW range.  At a typical (well chosen) site, a
turbine can operate at its rated power about 25% of the time.  One
turbine therefore provides about 1.5 million kilowatt-hours per year.
To provide ALL our electricity, we would therefore need "millions"
as you say--a little over 2 million turbines to be precise.

But I never suggested that wind could provide all our electricity.
What would you consider a "sizeable" percentage, anyway?  In the U.S.
we currently get 11% of our electricity from hydroelectricity and
20% from nuclear energy.  For wind power to reach these levels
we would need a few hundred thousand turbines--a large number,
to be sure, but not unthinkable.

I'm no economist, but many signs seem to indicate that wind energy
is finally becoming profitable.  Within the last month, my local
newspaper has reported plans for two new wind farms in the western
U.S.  The companies building these wind farms aren't doing it for
altruistic reasons--they're doing it to make money.  Construction
costs have come down over the years, while the price of electricity
is apparently going up (for the first time in a while).  If these
economic conditions persist, I would think that wind energy will become
comparable in importance to hydroelectricity within a few decades.

Dan