Solar Cells
Author: Anna Williams

A "solar cell" is a device which changes sunlight into
electricity. More technically, a solar cell is also
referred to as a "photovoltaic cell."

The term "photo" derives from the Greek word for "light,"
and the term "voltaic" comes from the word "volt" which
means "electrical force." A "cell" is a small receptacle or
container containing electrodes which generate power.

Thus, a photovoltaic cell is a container that creates
electric force, through light.

Whereas a solar cell can generate electricity from any
light source, its intended use is the collection of solar
energy from the sun.

- How a Solar Cell Works

The solar cell works as follows:

Photons (which are particles of light in sun rays) hit the
surface of the solar cell and are absorbed a semiconductor,
such as silicon.

These photons (bits of sunlight) knock electrons loose from
the atoms inside the semiconductor. The photons then push
the electrons along, leaving a "gap" in the atom. Another
electron is then pulled from an adjacent atom to fill the
gap. And so an electrical flow is generated.

The simplicity of this is that one atom has an extra
electron, and the other atom is missing one. This is
referred to as a "difference in potential." Nature, wanting
to remain balanced, tries to even things out by pulling
another electron from the neighboring atom.

A solar panel is made up of a group of solar cells linked
together to produce the desired amount of electrical energy.

A group of solar cells linked together can also be referred
to as a "module." Thus the terms "solar panel," and "solar
module," are synonymous to each other, and essentially mean
the exact same thing. "Solar panel" is the more common
term, and "solar module" is the technical term.

One can use solar panels individually or one can link
several together in order to generate more electricity.
When a group of solar panels are linked together, it is
called a "solar array". The more solar panels are included
in a solar array, the more power they produce.

Solar Power is a clean energy source which is virtually
unlimited. I say "virtually unlimited" because the sun
itself won't last forever. But we won't have to worry about
that for the next few billion years.

Since solar power is a clean energy source which has been
around for decades, one might wonder why its not used more.
The answer to this lies partially in the cost of producing
solar panels, as well as in the efficiency of the solar
panels.

We are currently in the second generation of solar panel
technology and verging on the third. A lot has changed
since the first generation. Solar panels a are becoming a
viable source of clean energy.

The first solar cells were relatively large and bulky
compared to our current models. In view of the amount of
energy and material required to produce them, and the
amount of energy they actually produced, it was more costly
to use solar energy than to use fossil fuels. The only
exception was in places where no fossil fuels were
available, such as in space.

With the second-generation solar cells, we attempted to
tackle this exact problem. We attempted improve
manufacturing techniques so as to reduce the costs,
materials and energy needed for the production of solar
cells.

Recently, major advances have been made in the production
of solar cells, which have reduced production costs.

One contribution in this area was the development of
techniques to coat glass or ceramic materials with very
thin layers of semi-conductive substances. This made it
possible to produce solar panels using only a fraction of
the semi-conductive material that was required earlier. The
production of solar panels using this second-generation
technology is referred to as "Thin Film Technology."

Third-generation solar energy technologies are currently
being researched and developed. The objective is to improve
the power of solar cells even further (while keeping
production costs to a minimum) in which case thirty to
sixty percent of the sunlight hitting the panels will be
converted into electricity. (Current solar panels only
convert about twenty percent.)

But regardless of third generation solar technology, the
second-generation solar cell is efficient enough to make
solar technology viable - and a host of new solar-powered
products have hit the consumer market.

Solar-powered calculators have been around for a while now,
we've all seen them. We have even seen a few other novelty
devices. But only in the last few years have solar devices
come into serious and practical use.

The last two years in particular have seen a virtual
explosion of solar devices hitting the market. Solar
flashlights (I've often wandered what use they were),
solar-powered radios, and, recently, solar battery chargers.

One can also now find a wide range of portable solar
chargers and panels, which are lightweight and easy to
transport, yet capable of providing a decent amount of
power in even the most remote locations. Solar chargers are
becoming a standard part of emergency preparedness kits and
wilderness survival kits.

All of this is a result of the developments in solar cell
technology, and the coming of the Solar Age.


About the Author:

Anna is the webmaster of
http://www.findportablesolarpower.com and
http://livingclean.com