Jaimie Bick
CS110
Technology- Solar Cells
December 17, 2007
Solar cells have been around for years and they can be found in a multitude of places,
some more unlikely than others. Certain calculators, road signs and even satellites utilize solar
cells and the sun’s energy to power their systems. In today’s world it seems only natural that we
should be “going green” and take advantage of the largest energy source known to man, the sun.
“On a bright, sunny day, the sun shines approximately 1,000 watts of energy per square meter of
the planet's surface, and if we could collect all of that energy we could easily power our homes
and offices for free.” Solar cells can directly convert the sun’s energy into electricity for general
use to all who take advantage of it.
Solar cells alter the sun’s rays into electricity by converting photons into electrons.
Photovoltaic cells; which are a group of cells that are electrically connected, are those that
actually do the converting. They are made of semiconductors, the most commonly used is silicon
and some added “impurities” such as Phosphorus. The silicon forms a crystalline lattice structure
with surrounding silicon atoms. When energy, in the form of heat is absorbed by the crystalline
structure it causes electrons held by the silicon and impurities to become free and flow in a
certain direction. That flow of electrons is a current and the energy from Phosphorus is negative
and known as n-type. When metal is placed onto the photovoltaic cells the current is drawn away
from the cells and can then be used to power a device. Because a current utilizes both a positive
and negative flow of energy, Boron is also used. When Boron becomes energized it looses one
electron and becomes positive. This is known as p-type. The n and p type together form an
electric field. “The electron flow provides the current, and the cell's electric field causes a
voltage. With both current and voltage, we have power, which is the product of the two. “
.
Outfitting a home for solar energy may seem like a daunting task but really it only
encompasses a few tasks. The first step is to decide to correct angle and orientation/direction to
face the solar cell panels. In general the panels should be faced south and angled equal to that of
the latitude of the area. The next important decision to be made is the size of the panels one
should choose. Well, size depends on the local area weather and the amount of energy used in
the home. If the meteorological data for the area indicates consistent cloudiness and a large
amount of energy is used in the home, larger solar cell panels should be used. Solar energy is a
growing trend, for those not only located in remote areas where electricity is not available but for
urban regions as well. Solar energy is an efficient and environmentally friendly way to produce
and use energy without the harmful effects of other systems. Using solar power to produce
energy is an effective way to take advantage of the largest resource available to us on earth, the
sun.
Annual Photovoltaic Domestic Shipments
1997-2006
Photovoltain Cell (Peak Kilowatts)
250000
200000
150000
100000
50000
0
1
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3
4
5
6
Year 1997-2006
Bibliography/Cites
-www.Howstuffworks.com
-www.eia.doe.gov
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