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By Kevin Casper
Anyone with an interest in alternative sources of green
energy has most likely asked themselves the question, How do solar panels work?
These days, solar panels are popping up in more and more
places.
From small landscaping lights to calculators and from call
boxes to large solar fields in the desert and even satellites.
It's hard to go a whole day without seeing solar power in
action. But how exactly do those panels turn the light from the sun into
energy?
This article will explain the basics of how solar panels
function and will then refer you to more technical resources if you desire to
learn more.
So How Do Solar Panels Work?
The
complicated science of how solar panels convert
sunlight into electricity is beyond the scope of this article, but it is
possible to understand the general idea of solar power production without
getting too technical.
Photons Into Electrons
The
solar panels you see on a landscaping light or a calculator are made of
photovoltaic cells.
The
purpose of these cells is to convert the light from the sun into electricity.
Photovoltaic
cells are typically comprised of silicon that acts like a semiconductor.
When
sunlight hits the silicon, the energy from the light is absorbed. Silicon is an
excellent choice because of its atomic-level properties.
In its
natural state, silicon has the space for eight electrons in its outer band, but
only carries four.
Therefore,
when two silicon atoms meet, each atom shares its four electrons with the other
and a stable, strong connection is created.
There
is no positive or negative charge here, however, since each atom is receiving
exactly what it needs.
For
silicon to work as a material to produce energy, it must be combined with
another element that has either a positive or negative charge.
An
element like phosphorus has five electrons, so when it is combined with
silicon, the bond will have eight shared electrons with one free electron that
is not needed by the silicon yet is still bonded to the phosphorus.
This
creates a negatively charged combination.
However,
for an energy current to flow, there needs to be a positive charge.
To
accomplish this, silicon atoms are also combined with an element like boron
that only has three electrons.
Now the
boron is completely bonded, but there is still a space in the silicon atom for
another electron.
In
solar panels, this positively charged plate is put together like a sandwich
with the negatively charged plate, and conductive wires are placed between
them.
When
the negatively charged plate in the solar panel is faced toward the sunlight,
the photons from the sunlight blast away at the solar panels until they
eventually knock the extra electron on the negative plate loose.
The
positive plate that has a space for the extra electron quickly gathers the
freed electron up.
As the
photons from the sun keep breaking off electrons, an electric current is
created.
At this
point, metal contacts are attached to each side of the photovoltaic cell so the
current can be drawn off and used as electricity.
Depending
on the size of the photovoltaic cell and the electric fields built-in to the
cell, the wattage of the cell will vary.
Limitations of Solar Power
Now
that you have a basic idea of how solar panels work, you might wonder why solar
panels aren't the primary source of power in the world.
The
problem is that it is still not a very efficient process for generating power.
The amount of electricity created by solar panels is relatively low compared to
the size of the panels.
Plus,
the angle of the solar panels is very important; if the panels are not facing
the sun just right, the efficiency can drop considerably.
Solar panels are getting better and
better, but engineers are still searching for ways to make them more efficient,
smaller and easier to maintain.
Kevin
Casper
is a freelance writer, musician, and an amateur photographer. He holds a
PhD in Philosophy from Louisiana State University in Baton Rouge.
https://greenliving.lovetoknow.com/How_Do_Solar_Panels_Work
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