On 16 Mar 2008 20:47:43 -0500, "Ash Wyllie" wrote:

Dan Luke opined

"Dan" wrote:

There are enough coal and oil shale reserves in the US alone to
provide internal demand needs for 150-500 years

But they have serious environmental downsides, both in extraction and
burning.

Solar energy may be harvested in several ways
http://en.wikipedia.org/wiki/Solar_updraft_tower . Wind power harvest is
experiencing rapid growth in the U. S., showing potential to be a serious
contributor to the national grid, increasinig ten-fold in ten years:

=================
In recent years, the United States has added more wind energy to its grid
than any other country; U.S. wind power capacity grew by 45% to 16.8
gigawatts in
2007.[34] Texas has become the largest wind energy producing state,
surpassing California. In 2007, the state expects to add 2 gigawatts to its
existing capacity of approximately 4.5 gigawatts. Iowa and Minnesota are
expected to each produce 1 gigawatt by late-2007.[35] Wind power generation
in the U.S. was up 31.8% in February, 2007 from February, 2006.[36] The
average output of one megawatt of wind power is equivalent to the average
electricity consumption of about 250 American households. According to the
American Wind Energy Association, wind will generate enough electricity in
2008 to power just over 1% (4.5 million households) of total electricity in
U.S., up from less than 0.1% in 1999. U.S. Department of Energy studies have
concluded wind harvested in just three of the fifty U.S. states could
provide enough electricity to power the entire nation, and that offshore
wind farms could do the same job.[37]

-Wikipedia http://en.wikipedia.org/wiki/Wind_power

Texas had a big problem a few weeks ago: the wind stoppped blowing. There was a
hell of a scramble to get the fossil fuel plants online.

The big problem with wind is that it is not constant, and unpredictably so. So

Like here in lower Michigan. We have almost the ideal average wind
speed, but unless close to one of the lake shores it's usually way too
fast or calm. However for the individual home owner there are
variations of the Savionus (sp?) S-rotor that work well out in the
open. Here we're surrounded by trees on three sides and putting a
generator high enough to clear the trees would be impractical from an
economic viability. Out on the farm mixed in with active and passive
solar they'd probably give us an independent level from the mains of
around 75% with enough excess to actually make money. Not much, but
at least come out on the positive side of the ledger.

I'd like to experiment with passive solar water heating, supplemented
with "on demand" hot water heaters for the kitchen and shower.. I
cold add a green house to the south side of the shop and probably heat
enough water the cut the heating bills for the house and shop in half.
With a large enough reserve we *might* be able to heat enough water to
supplement the gas fired forced air heat, but I'm afraid for
electricity we'd come out way on the short side. As I've mentioned
before, I was given a figure by a consultant of $50,000 to get about
that 75% and a payback of over 20 years.
Electric rates are currently around 10 cents per KWH and gas is
relatively inexpensive as well. Nor do we receive any subsidies
compared to California where rates are near 40 cents at peak demand,
they receive about a 50% subsidy and have far more sunlight which
also happens to be more direct.
you must have conventional backup ready to go. So all you save is fuel costs at
a huge capital expense. A gigawatt of wind power will not replace a gigawatt of
coal, or nuclear power.

-ash
Cthulhu in 2008!
Vote the greater evil.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com