Introduction to Solar Energy

1
Introduction to Solar Energy

• An overview of the
  technologies and applications
  

Modified by Georgia Agricultural Education
Curriculum Office
June 2002
2
On July 4, 1997, the Pathfinder spacecraft
bounced to a stop on Mars. The next day, the
rover Sojourner rolled out of one of the lander
petals onto the surface of the planet to begin
its mission of exploration.

3

Sojourner was able to move around the planet and
examine rocks like this one named Yogi
located 20 feet from the Pathfinder lander than
ks to the power generated by the solar panel on
its back.

4

Dramatic as this was, it was just
one use
of solar energy.

• To many students, exciting projects like this
  are what solar energy is all about.
  
• But there really is much more to solar energy
  technologies, how they are being used, and how
  they impact our lives today. This presentation
  will introduce you to the entire field of solar
  energy.

5
Lets begin our overview of solar energy by
askingWhat do you see here?

• Take a close look
• is this the profile of a beautiful young
  lady, or the face of an ugly, old woman?
  
• Theyre both here, but for a variety of
  reasons that make up your own individual
  psychological make-up, some of you see one woman,
  some the other.

6

• When people think of solar energy, the same thing
  often happens. Some see it as something for the
  future, others see it as something that is here
  today.

7
If you think solar energy is something to be used
in the future . . .

• you may be picturing something like this solar
  array used by the space shuttle to provide for
  power needs in outer space. There are people who
  think that solar energy is something not quite
  down-to-earth and not ready to use today.

8
However, there are other people who think
of solar energy as something thats been around
for a long time.
Solar collector for heating water
A home in California in 1906
9
For hundreds of years, people have wanted to
harness the suns power for weapons, heating, an
d many other uses to make their lives more comfo
rtable.
10

• Actually, the first solar water heating collector
  appears to have been built in the 18th Century by
  a Swiss scientist who constructed a simple wooden
  box with a glass top and a black base. It
  trapped solar energy, and the collector reached a
  temperature of 190 degrees Fahrenheit.

11
So which view of solar energy-- for the future
or for today is correct?

• Probably a little of both.
• Solar energy will certainly play an important
  role in the future energy needs of our planet,
  but its also here today and ready for hundreds
  of uses in homes, businesses, and industry.

12
The sun is an inexhaustible power supply. It
brings enough energy to our planet every single
day to meet a full years worth of energy for
everyone on Earth.

• And during the past century back to 1891, in
  fact, when the first solar collector was
  manufactured in the United States, U.S. industry
  has developed a variety of products that have
  proven both reliable and cost-effective in
  meeting all kinds of energy needs.

13
The batteries in this solar-powered light in a
remote part of Key West, Florida, are charged by
the sun during the day to provide power for
street lighting at night.

14

• But to many people, solar power today means
  just reliable calculators, watches and other
  simple home products like this lantern that use
  solar power instead of electricity to charge the
  batteries.

15

• They dont realize that millions of people around
  the world use solar energy because it is the only
  available, reliable power source for many of
  their basic needs such as lighting and water
  pumping.

16

• Meanwhile, do-it-yourselfers have long tried to
  build their own solar systems to take advantage
  of the free power provided by the sun . . .

17
The owner of a small laundry in northern Florida
tried to build his own concentrating system for
water heating. (We dont know if the sign in the
background was put up before or after this
homemade system was built.)

18
But we do know that growing public concern about
environmental problems . . .
19
including global warming, acid rain and toxic air
emissions, has in recent years turned a great
deal of attention to environmentally friendly
solar energy systems.
20

• The nonrenewable sources we use today including
  coal, oil, kerosene, diesel, propane and natural
  gas are all limited in availability, and are
  also partly to blame

21
Meanwhile, there is one energy source that is
free and inexhaustible. Its like a giant
nuclear reactor only this one is located 93
million miles away.
22

• Its not uncommon around the world to see
  solar systems used along with the traditional
  ways of life to become an integral part of
  peoples lives.

23
The house of the future?

• This zero-energy house in the Netherlands has
  30m2 of PV panels for power generation and 12m2
  of solar collectors for water and space heating.

24
No matter what the future will be like, one thing
is for certain some type of energy will be
needed to power it.

25
What will that energy source be?
The answer ought to be obvious.

Its been up there all the time.
26
Discussion Questions

• Why do you think solar energy is not used more
  today?
  
• Do you think governments should adopt measures to
  use more solar energy in the future, or rely on
  fossil fuels as long as they are available?
  
• What are some of the economic, social, and
  environmental issues involved in the use of solar
  energy?