ORIGINALLY PUBLISHED IN LIMA NEWSLETTER SEPTEMBER 1993
 
      RUN YOUR COMPUTER AND OTHER HOUSEHOLD DEVICES 
     ON CLEAN DEPENDABLE SOLAR POWER.  
     by Charles Good 
     Lima Ohio User Group 
      
     With the recent development of inexpensive efficient sine wave (or near
sine wave) inverters it is now possible to power all the AC electric appliances
in your house including our 99/4A computer systems using a DC power source.
The most elegant and environmentally friendly source of DC electricity is a
photovoltaic panel, the sort of thing that allows light to power many of
today's calculators.  I have a TI99/4A computer system running completely on
solar power, and my CC40 computers run on NiCad batteries that are charged with
solar battery chargers.  This is the environmentally thing to do! For a few
$100 you can run a fully expanded 99/4A system with solar power.  For an
investment of about $11000 you can disconnect your home from the power grid and
generate all your home's electricity requirements from the sun.  Once the
initial investment is made in photovoltaic panels, these devices continue to
produce "free" electricity basically forever.  Unlike a lot of other solid
state electronic devices, most photovoltaic panels do not wear out. 
      
     Conventional sources of electric generation are bad for the environment.
Electricity made from fossil fuels consumes non renewable resources and
produces lots of pollution (soot, sulfur dioxide, nitrous oxides) that causes
smog, acid rain, and health problems.  Carbon dioxide, which is what you get
from an absolutely "clean" burning of anything, is said to be a major factor in
the planet's gradual warming trend (global warming).  Carbon dioxide produced
by the burning of fossil fuels is a major source of the increasing percent of
carbon dioxide in the earth's atmosphere that has been noted over the last
several decades.  Electricity generated from nuclear power produces no carbon
dioxide, but the potential dangers of nuclear power are enromous as evidenced
by what happened at Chernobyl.  Also, we still havn't figured out what to do
with the high level radioactive waste from nuclear power plants, waste that
remains hideously lethal for thousands of years. 
      
     The electric bill you pay every month pays for the power company's
hardware and for the fuel the power company consumes.  As the years go by you
can expect these fuel and hardware costs to increase and your electric bill to
also increase.  WHAT YOU DON'T PAY FOR with your electric bill are some direct
and numerous indirect costs related to electrical generation.  Nuclear
generated electricity has direct costs that our children and many generations
of grandchildren will have to pay.  Nuclear power plants gradually become so
radioactive that routine maintenance becomes impossible, at which point they
have to be permanently shut down.  They usually cannot just be disassembled and
carried away because of this radioactivity.  The reactor core must remain in
place and be be monitored, maintained, and patroled with secutity guards for a
couple of hundred years.  In almost all cases electric utilities that own these
nuclear power plants plan to pay for these "decommission" costs from their
current rate base (ie. our children).  Then there are the perpetual costs of
monitoring high level nuclear wastes and keeping these wastes out of the
environment for thousands of years. 
      
     There are lots of indirect costs associated with making electricity from
traditional fuels.  What is the military cost of keeping the Persian Gulf open
and the oil flowing our way? How about the cost of the rot to buildings, cars,
and people's lungs caused by the pollution of coal generated electricity? What
is the dollar cost of environmental damage due to oil spills, coal mine waste
piles, forests and lakes killed by acid rain, and reduced crop yields due to
acid rain? I am a chromic asthmatic and spend hundreds of dollars every year on
drugs to keep my problem under control. I will have to do this for the rest of
my life.  I know that for myself foul air means a greater chance of an asthma
attack, more drug use to control these attacks, and very occasionally an
overnight stay in the hospital if the drugs don't work.  How many cancers are
caused from nuclear waste and nuclear power plant accidents? How many extra
billions of dollars are spent annually on health care and how many work days
are lost due to pollution from electrical generation? How do you put a price on
beauty? What is it worth to see the North rim of the Grand Canyon from the
tourist facilities on the South rim? Often this is difficult because of the
haze produced by a coal fired electric generation plant 50 miles away.  It is
difficult to quantify these indirect costs associated with the usual methods of
generating the electricity you use, but I suspect they add up to several times
the cost the country's monthly "electric bill". 
      
     Electricity generated with photovoltaic panels is virtually pollution
free!  There are no poisonous gasses or green house gasses (ie no carbon
dioxide), no radioactive waste or danger, and no consumption of non renewable
fuel resources.    Several tens of thousands of private homes in this country
are  "off the grid" and generate all their electricity from solar.  These
households  have NO MONTHLY ELECTRIC BILL to pay.  The only continuing expense
for such "off the grid" homes is replacing batteries every 10-15 years.  Many
electric utilities charge $10 per foot to bring power to loctions not within
easy reach of an existing power line.  For homes more than 1/4 - 1/2 mile from
the nearest power pole it is often cheaper to stay off the grid and purchase
the solar equipment needed to make all their own power than it is to pay the
power company to extend their electric lines to your home.  The exact break
even point varies from one electric utility to another.  For locations near a
power line simple calculations suggest that it is cheaper to use the power
company's power than to invest in solar electricity, but that is only because
these calculations do not take into account the indirect costs outlined above. 
      
     Photovoltaic panels are based on silicon, mainly obtained from common
quartz sand.  Silicon is a resource we are not likely to exhaust since it is
one of the most common types of atoms found in the earth's crust.  Panels
consist of a number of silicon crystal or amorphous silicon photo cells wired
to produce enough voltage (usually about 16 volts) when the sun shines on the
cells to charge a 12 volt battery system.  These cells are all sealed from the
elements within the panel.  Lower voltage panels are available.  Higher
voltages can be obtained by wiring several panels in series. Unlimited
increases in power (more watts) can be obtained by wiring additional solar
panels together in parallel.  The modularity of solar panels makes them
attractive to small power users or those with limited funds who are interested
in a little energy independence.  The single solar panel on my roof is
identical to those used by large scale utility owned solar electricity
generating facilities in California.  They have 1000's of panels, I have only
one.  When money is available it will be easy for me to add more solar panels
to my existing small scale home solar electric generating system. 
      
     The first experimental silicon crystal photovoltaic panels were made in
the middle 1950's.  Panels manufactured in the late 50's are still in use and
are still producing almost as much electricity as they did when they were new.
The power (watts) of solar panels decreases a little during their first couple
of years of operation due to a darkening of the panel's coating.  After that,
power output does not continue to deteriorate.  Apparently THESE DEVICES DO NOT
WEAR OUT!  The failure rate of existing silicon crystal photovoltaic panels is
less than 2 per 10000 panels per year. 
      
     In the 1980's production techniques began to improve and manufacturing
costs decreased.  Because of the increased volume of photovoltaic sales and
continued manufacturing efficiencies, costs of photovoltaic panels continue to
come down.  It is now possible for ordinary consumers such as ourselves to
purchase new photovoltaic panels for as little as $6 a peak watt in small
quantities ($449 for one new 75 watt panel).  Used panels (they don't wear out)
cost even less.  Manufacturers offer amazing warranties of 10, 12, or 20 years
on new panels, guaranteeing the panel will produce at least 80% of its rated
power for at least that length of time.  A peak watt is the power output of the
panel near the middle of the day when the sun is at its brightest.  Ohio
averages 3.9 "peak" hours of sun per day.  The rest of the contenental U.S.A.
averages between 3.5 and 6.0 peak sun hours per day. These are annual averages
and take into consideration average cloud cover and seasonal day length
variation.  Solar panels will continue to produce electricity at their rated
voltage when the sun is low in the sky or when there is a cloud cover, but
power (watt) output will be less than "peak". 
      
     What can you do with electricity made with solar power.  After all, the
power output of solar panels is not continuous.  You get no power at night and
reduced power if there is less than "peak" sun.  One alternative is to store
the electricity in lead acid batteries.  This is what "off the grid" home
owners do.  Solar panels will last more or less forever, but unfortunately
batteries won't.  The best batteries available to "off the grid" home owners
have to be replaced every 15 years.  Battery replacement is the only recurring
expense of remote solar electric systems.  Another alternative is to sell your
solar electricity to the local power utility, and then buy it back as needed
(at night for example).  The power company acts as your battery, storing your
electricity for later use.  Laws require that electric utilities purchase power
from small private producers.  There are three disadvantages to selling power
to your local electric company.  1- You have to pay for an expensive
"synchronous inverter" interconnect which will turn your solar DC electricity
into 60 cycle AC current that is EXACTLY synchronized with the 60 cycle power
company current.  2- If there is a power company power failure your own
generating system is also automatically shut down by the synchronous inverter
interconnect.  The power company doesn't want its power lines energized while
the repair crew is trying to fix things.  Thus, an interconnected small private
electricity source CANNOT be used as backup electricity.  3- In most states the
power company is allowed to pay you LESS per kilowatt hour for your electricity
then you have to pay the power company for its electricity. 
      
     I have a miniature 99/4A computer system (99/4A console, tape recorder,
hexbus interface, hexbus printer plotter, wafertape drive, small B&W TV for use
as a monitor), an 18 watt fluorescent light and a shortwave radio receiver all
(except the TV which runs directly off of a 12 volt source) powered by an
inverter connected to a 115 amp hour deep cycle 12 volt battery.  The battery
is charged with a 27 watt solar panel occupying less than a square yard on my
roof.  I purchased this panel new with a 12 year warranty for about $200
including shipping ($7 per peak watt).  Total power draw of all these devices
(taking into account the 90% efficiency of my inverter) is 80 watts from the
battery.  I can run ALL this stuff simultaneously for 13 hours and not
dangerously discharge my battery.  For every hour I run all these devices
simultaneously (usually I don't run them all at once) it takes my 27 watt solar
panel 5 peak hours to recharge the battery.  This takes into consideration the
fact that you have to pump into a battery 125% of the electricity you get out
of the battery.  If I had a fully expanded 99/4A system with a peripheral
expansion box hooked up to this battery, I would want a second solar panel to
speed up battery recharge time.  I expect soon to purchase some additional
solar panels.  There lots of square yards left on my roof. 
      
     I also have a variety of solar powered nicad battery chargers which I use
to charge batteries for use in my CC40 computer, TI-74 computer, and my hexbus
peripherals.   The charger I use for the 4 AA batteries I put in my CC40
computer is about the size of a cigarette package.  It fully recharges 4 AA
nicad batteries in 14 hours of "peak" sun.  I keep this charger in a sunny
window with a set of batteries inside, and another set of charged nicads in my
CC40. 
      
     I purchased all my solar equipment from REAL GOODS of Ukiah CA. (The
company name and my last name are the same only by coincidence.  I am however,
impressed enough with the company and its products that I purchased $90 worth
of their common stock.)   They are this country's largest retailer of
solar electric panels and other products for "off the grid" homes.  Another
large retailer of solar panels and related products is SUNELCO of Hamilton
Montana. 
      
     A quote from the REAL GOODS "Alternative Energy Sourcebook" gives you an
idea of what is possible with a solar electric home.  For $10700 the company
will sell you its "Remote Home Kit 4".   This includes everything you need;
solar panels, mounting hardware, batteries, inverter, fused load center, safety
disconnect, meters and other equipment all U.L.  listed and all in compliance
with the current National Electrical Code. 
     "In the world of photovoltaic home systems, this is a giant.  It will
power a large energy efficient home with all the comfort and convenience of a
city home hooked to the power grid....Use your vacuum cleaner, washing machine,
microwave oven, entertainment equipment and computers with the confidence that
you have a substantial energy system composed of the best components
available." 
     It is assumed that such an all solar electric energy efficient home will
use only fluorescent tubes or compact fluorescent light bulbs for lighting and
will not use electric resistance for space heating, clothes drying, and water
heatng.  Alternative sources of energy such as direct solar water heating,
propane, wood, and a clothes line are available for these purposes.  The
"Remote Home Kit 4" produces 4600 watt hours per day with 5 peak hours of sun.
You can always get more electricity by adding more solar panels. 
      
     According to the Electric Power Research Institute in California, "25
percent of today's U.S. electricity needs could be met by solar cells deployed
over an area of less than 8 percent of the area used by the U.S. military."
Lots of military bases are scheduled for scaling down or closure in the next
few years.  I wonder what will happen to all that land? 
      
     I believe solar electricity will be a BIG part of the planet's energy
future.  Electric utilities in California are now actively investing in large
solar electric power plants.  In the near future I envision many utility owned
solar power plants.  They are now cheaper to build and simpler to operate than
nuclear power plants and can be used to meet peak daytime industrial and air
conditioning electric demands.  I also envision solar panels on the roofs of
factories, office and apartment buildings, and private homes interconnected to
the local power grid and I envision lots of "off the grid" solar electric
systems bringing electric power to all corners of the planet while producing
electricity without stinky poisonous exhaust,  radiation, or greenhouse
gasses. 
      
     If all this sounds interesting call either of the companies below and ask
for their catalogs.  SUNELCO has a very extensive informative 123 page catalog.
REAL GOODS has a free color catalog and publishes the "1993 Alternative Energy
Sourcebook", the most complete single source of information there is on this
topic and the source of much of the information in this article.  The cost of
this 518 page book is fully refunded with the purchase of $100 worth of REAL
GOODS goods. 
     REAL GOODS 
     966 Mazzoni St. 
     Ukiah CA 95482-3471 
     Phone 800-762-7325 
 
     SUNELCO INC. 
     100 Skeels St. P.O. Box 1499 
     Hamilton Montana 59840 
     Phone 800-338-6844 
     .PL 1