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Solar cooker session at IUFRO World Congress
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Subject: Solar cooker session at IUFRO World Congress
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From: ala@kanto.cc.jyu.fi (Ari Lampinen)
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Date: 11 Jul 1995 19:40:43 +0300
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Article: 1641 of bionet.agroforestry
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Newsgroups: bionet.agroforestry
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Organization: University of Jyvaskyla, Finland
Latest info: http://kaapeli.fi/~tep/iufro.html
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IUFRO XX World Congress
August 6-12, 1995, Tampere, Finland
Caring for the Forest: Research in a Changing World
TEP will organize a satellite meeting in this major forest research congress
(3000 attendants expected) with a topic "Solar cookers as a means for reducing
deforestation". There will be a seminar of 2 hours (on 10th of August) and
cooker and cooking exhibitions (during the congress week). The congress is
organized by Finnish Forest Research Institute.
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SATELLITE MEETING: 10th August 1995, 19:30 - 21:30, University of Tampere, Main
Building, room U 11
Solar Cookers as a Means for Reducing Deforestation
Chair: Riitta Wahlstrom, co-chair Ari Lampinen; Technology for Life and
University of Jyvaskyla, Finland
Programme:
* Claus Montonen, Technology for Life and University of Helsinki, Finland:
Using solar cookers in developing countries, different aspects
* Anita Mahandrar, Centre for Rural Technology, Nepal: Solar cookers as a
means to reduce deforestation in Nepal
* Ulrich Oehler, Group ULOG, Switzerland: Solar cooking in Switzerland -
use of cookers in Africa and India
* Artur Marques da Costa, Portugal: Experiences of using solar energy
* Discussion
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email: ala@jyu.fi
WWW: http://kaapeli.fi/~tep
Article 15241 of sci.energy:
Path: samba.oit.unc.edu!concert!gatech!howland.reston.ans.net!usenet.ins.cwru.edu!lerc.nasa.gov!lerc.nasa.gov!Phobos
From: GLANDIS@LERC.NASA.GOV (Geoffrey A. Landis)
Newsgroups: sci.energy
Subject: "Solar Futures" (article on PV energy)
Date: Mon, 26 Jul 1993 15:49:59 -0500
Organization: NASA Lewis Research Center
Lines: 307
Message-ID: <9307261549.AA59028@Phobos>
Reply-To: GLANDIS@LERC.NASA.GOV (Geoffrey A. Landis)
NNTP-Posting-Host: glandis.lerc.nasa.gov
X-Newsreader: InterCon TCP/Connect II 1.1
This is an article I wrote for a magazine
column a few months back. I thought I'd
post it here and see what comments it draws.
Solar Futures
Geoffrey A. Landis
Over winter vacation I stood on Clearwater
Beach, just west of Tampa, Florida, and watched
the sun set over the Gulf of Mexico. Actually,
the sun did not so much set as dissolve into the
brown sludge on the horizon. The Florida
humidity makes for part of this sludge, but if you
run your eyes along the horizon to the
smokestacks just barely visible about ten miles
north, you can see where most of it comes from.
A coal-burning power plant. This week a mild
inversion over Tampa trapped coal smog over
the city like a dirty brown dome. On a clear day
the output of the coal-fired power plant is a
wide brown streak that runs along the ocean
from the smokestacks in the north as far as you
can see in any direction.
I'm not sure why people stand for it. If a
nuclear plant were leaking poison, people would
be picketing and writing letters to the
newspaper and generating lawsuits. For reasons
I've never quite understood, coal-fired power
plants seem immune from the environmental
movement. America's future is coal, energy
analysts say. Coal, a cheap, plentiful energy
source that doesn't have to be imported, is
touted as the solution to the energy crisis for
the next five hundred years.
A billion years or so past, the atmosphere of
the Earth was carbon dioxide. I don't seriously
believe that we will be able to return the Earth
to a CO2 atmosphere, but we seem to be making
a serious effort.
When I first started working in the solar
energy field in 1977 (working on glass
encapsulation techniques, an approach that has
since become ubiquitous), our goal was to
develop a technology to manufacture solar
panels with a 20 year lifetime at a cost of 50¢
per watt. It seemed a distant, nearly
unreachable target--the cost was more like a
hundred dollars a watt then--but we calculated
that if we could hit 50¢, solar-generated
electricity could be cheap enough to start
competing with oil and coal-generated
electricity.
Figuring for inflation, that would come to
about two dollars or so per watt in today's
dollars. In million-watt quantities, PV panels
sell for about five dollars a watt now. I've
spoken to several of the manufacturing
companies, and they all agree that they could
easily produce panels for two dollars a watt or
less using today's technology, if they had a
market big enough for them to run efficient
mass-production.
And there are half a dozen different
technologies that can reach this goal: sun-
concentrating systems; thin amorphous-silicon,
copper indium diselenide, or cadmium-telluride
films sprayed down on glass substrates;
crystalline silicon made by innovative low-cost
crystal growth techniques. The exciting thing
about working in the solar cell industry is that
there's a new breakthrough every two years.
So if we can hit the cost goal, why are we still
building conventional power plants?
Many reasons. For one thing, we--in
America, anyway--are not building new power
plants. The "new" plants that are coming on
line are actually ones that started construction a
decade or more ago, when the forecasts were
for tremendous growth in electrical demand. In
the eighties, though, instead of the huge growth
in demand that had been forecast, there was a
huge and mostly unexpected power glut. New
power plant orders were canceled;
Westinghouse shut down the production line
that made the coal-fired generators.
Why an energy glut? Like most things, it was
a combination of factors. For one, in the energy
crisis of the '70's, people suddenly noticed that
energy cost money. Enough money to notice.
As awareness increased, when new facilities
were built or old ones renovated, architects and
engineers started including energy use in the
design equation. Energy efficiency--which had
always been thought trivial before--increased
tremendously. At the same time, heavy industry
and steel-making, some of the largest users of
power, moved overseas, further decreasing
usage. And finally, a new animal arrived on the
scene: PURPA.
PURPA , the public utilities regulatory
purchasing act, was enacted by Congress in
1978, and took effect in 1980. The purpose
was to encourage renewable energy. The law
stated that electric power utilities must
purchase power from independent power
generators at their "avoided cost" (i.e., the
money that they save by not generating it
themselves). Suddenly the whole electric
industry changed: utilities became power
brokers, not power producers. The idea was to
encourage homes and businesses to put up solar
panels and windmills to produce power, and
then to sell the excess power produced back to
the utilities. Instead, it had an entirely
unforeseen result: co-generation.
Industrial processes require heat. Heat for
forging steel. Heat for buildings. Heat from
incinerators. In the past, the waste heat was
just... well, wasted. But if the utilities would
actually buy as much power as you could
generate... well, why not add a small electric
generator, and make a few dollars with the heat
that was there anyway?
During the eighties, the small increase in
electrical demand was met not by new
generating stations, but by co-generation of
power from 'waste' heat. For the nation as a
whole, this resulted in a boost in energy
efficiency. For the fledgling solar power
industry, though, just as the technologies were
beginning to develop, the electrical utility
market virtually disappeared. Some companies
folded. Others changed their plans.
There are other applications for solar power,
and the number are growing. In the early
eighties, solar cells appeared on watches and
calculators: hardly a major portion of the world
power usage, but a huge market for the brand-
new solar industry.
Then there was powering lights for
billboards, often located far from the power
grid. Charging the radio batteries on boats and
RVs. Power for houses that are so remote that it
would be prohibitively expensive to bring power
out from the electrical grid (keep in mind that
it costs something like twenty thousand dollars
to extend the electrical grid a mile!).
The cumulative world output of solar cells to
date, counting everything from disposable
watches that have long since joined the landfill
to roof-tops arrays on mountain huts, would
come to 400 megawatts. If this were all hooked
up together, on a clear day at noon it would
produce about the electrical output of a single
electric power plant.
(I'm talking about electricity here. Solar heat
and hot water are a different matter, and already
economically favorable in much of the U.S.).
What will it take to make an impact on utility
power?
A typical American home might require ten
kilowatts--ten thousand watts. When we rate
solar panel capacity in 'watts,' however, this
means the power that the panel is capable of
generating at noon on a clear day. We
Americans, though, don't want electricity just at
noon on clear days. We want our electricity
whenever we click the switch: television in the
evenings, lights to read by, electric stoves to
cook dinner. And electric utilities want their
power available all the time. After all, if solar
power is only available during the day, they'd
have to build conventional power plants for the
night, and let these plants sit idle half the time.
Well, there's storage. Batteries.
Advances in storage batteries, however, have
far lagged behind advances in solar panels. If
you want electricity at night, you pay dearly if
you have to generate it in the daytime and
charge batteries with it. Batteries are
expensive.
Oddly enough, though, there is a market for
utility electricity that requires no storage. In
the US, and especially in the sunniest regions of
the US, the peak market for electricity comes
in the middle of the day. Industry, after all,
mostly operates from 9 to 5, and in much of the
US, the big demand for electricity is in the
summer: air-conditioners. Here solar and
conventional generation work together in
perfect harmony. Conventional (which means
coal in most of the US) generators provide
continuous base power, and solar provides the
required peak power during the days. This
fortuitous synergy between solar and
conventional power means that something like
ten to twenty percent of the US power use can
be provided by solar without requiring storage
or conventional plants for night power.
Americans spend 175 billion dollars a year on
electric power. Even 10% of this is an
extremely large business.
Solar cells also have another advantage for
utilities: they can be bought in small (for a
utility) amounts. Building a conventional plant,
for example, requires that a utility put up a
billion dollars in construction money for a
power plant that won't produce power for ten
years. In the eighties--the power glut--power
utilities had to deal with huge non-performing
debt on the money borrowed to build power
plants to meet need forecast in the seventies.
Need that didn't materialize.
But you can buy solar panels of a few
kilowatts, or a few megawatts, and get them
producing power in less than a year. Solar
power can grow with the need, instead of
requiring perfect vision from a cloudy crystal
ball.
So the American utility industry is, very
slowly, starting to look again at solar power.
Right now, much of the sales to the power
industry is for evaluation and testing. The
utilities see the future, and want to get
operating experience.
In the long term, though, daytime peak
power for the U.S. won't be enough. Thinking
over hundreds of years, coal power must be
replaced by something environmentally benign.
But the United States is not the entire world.
The biggest environmental crisis of all will
come, when the third world starts to demand a
standard of living equal to that they see in the
industrialized countries. There are half a
million villages in India which have no electrical
power at all. For such villages, any electrical
power is a great step forward. Mexico, South
America, Africa, Asia... most of the world's
population is not used to an electric power grid
that produces power at the flip of the switch,
any time night or day. Most of the world will
find a technology that delivers electricity in the
daytime to be a great improvement in standard
of living. Most of the world will embrace solar
power.
It's not the cost of the generating stations
themselves that's important--it's the cost of the
distribution network that sends the power
where it's needed. Solar electricity can be
generated where it's needed.
So the future for solar is bright. Every few
months I read about another factory being built
to produce solar panels, not just in the U.S., but
in Mexico, India, Italy, Switzerland, Iran, Brazil.
It's been a long, slow road, but the technology is
here, and the markets are developing rapidly.
The energy glut is fading, and future for solar is
bright.
But then, so is the future for coal. There's
plenty of coal to burn, even in the third world--
as long as you're not too choosy about how clean
the coal is. There are two paths for us, and we
could take either one.
Coal, or solar? One way or another, the
future is at hand.
copyright1993 by Geoffrey A. Landis
Geoffrey A. Landis
NASA Lewis Research Center mailstop 302-1
GLANDIS@LERC.NASA.GOV