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Solar cooker session at IUFRO World Congress




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 

-------------------------------------------------------------------------------
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