From: Michael S. Lorrey (retroman@turbont.net)
Date: Tue Sep 05 2000 - 21:21:33 MDT
GBurch1@aol.com wrote:
>
> Driving along the freeway on many of these 106 degree (that's 50, for you
> progressives), cloudless days, I can't help but be struck by the obvious
> direction we should be going, which is solar energy in the most direct
> fashion. So how are we doing? Can someone point me to good resources to
> quickly get up to speed on the state of the art in direct photovoltaic
> technology and the rate of progress in that field? How close are we to
> practical industrial-scale photovoltaics?
When I was in Seattle, a freind of mine was president of US Solar Power, and
they were in a development project with the Dept of Energy and a couple other
companies to develop flexible amorphous silicon PV roofins shingles. The plan
was to produce these at industrial rates, which would allow the per kWh cost of
these units to drop to about $0.12 per kWh, which is considered the best
acheived to date. I lost touch with this project, and I don't know what the
status is currently. Supposedly they had a demonstrator house built in 1995, but
I never saw it, and since the GOP cut off most Energy Dept funding for
conservation in 1994, I don't know if any funding has increased since.
Conservation programs tend to drift toward the least cost source of conserved
energy. When I was in the business, they were buying cogeneration, lighting and
heating conservation energy at a rate of 1-2 cents per kWh, which is one tenth
the cost of the solar shingles I mentioned. Since the end of the Cold War, start
up utility companies have been buying converted jet engines to run on natural
gas to generate power and heat
Practical industrial scale photovolatics? Well, what technology are you talking
about? There are essentially five solar technologies to consider:
PV: type efficiency
- amorphous silicon 10%
- monolithic silicon 12-20%
- gallium arsenide 20-33%
- gallium arsenide/gallium antimonide 33-36% (theo. max. for PV)
- solar thermal generation 50-80%
amorphous silicon is the lest expensive to manufacture, on both a per cell and a
per kWh basis. GaAs/GaAnt cells are extremely expensive cells, and are only cost
effective really in satellites, although Krystal Power in Issaquah, WA was
working on a Natural Gas generator that used GaAs/GaAnt cells to generate power
from the combusion flames several years ago.
There have been solar thermal generation systems developed, most notably one in
southern CA that I believe is now offline due to age and operating expense.
The main downside to solar technology is that its not always sunny wherever your
generator is. While the southwestern US does have a nice reliable number of
sunny days per year to count on, the rest of the country does not. The Sahara
desert is an excellent place for a major solar generation system, while
sub-saharan africa is not. The few sunny days you have, the less cost effective
it is to use solar power. Utilities in the western US only pay for the
installation of solar systems in homes that are too remote to run grid power
cost effectively. If Lake Powell and other western hydro dams are drained,
though, I think you will see this situation change, which may be the real reason
why the Sierra Club has been lobbying for that for several years.
The main restraint against ANY alternative/renewable energy generation system is
capital costs and the capital market. Renewables are extremely capital
intensive projects (70% of per kWh cost), while they cost little, usually, in
terms of operating costs. Fossil fuel generation, on the other hand, is cheap
capital wise, while 70% or more of the per kWh cost is due to operating expenses
(fuel, maint, labor, etc...). In any economy where interest rates are rising or
are high, construction of renewables is not a cost effective solution. The need
for interest rates in the sub 4% range to achieve cost effectiveness typically
requires that these renewable projects either be owned by or subsidized by
government lending, which obviously commands the lowest interest rates.
The other big restraint is the NIMBY attitude. Environmentalists want us to all
use solar power, but they don't want those solar panels or windmills cluttering
up the landscape view from their own homes or on their own commute routes...
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