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To
understand the details of this question, we must first look at how the
sun produces energy, and then understand the components of a solar unit
and how each one does its part to generate useable electricity. With
this simple solar power explanation, you’ll finally be able to answer
the question of how solar power works for yourself and how its powerful
technologies will ultimately be able to stop climate change.
| How
does solar power work? |
Part 1- The Sun as Energy
Creator
 Most people understand
that the sun gives life to all things on this planet through its light
and heat, but the sun also produces many other things. The process of
solar energy began in the center
of the sun, almost
a million years ago. Photons are created through the fusion of atoms in
the sun's core. They will eventually be what
generates solar power, but not until they are able to escape from the
sun.
It generally takes a
photon over a million years to escape from the center of the sun to the
sun’s surface. Once at the surface, the photons are sent hurtling out
into space in all directions, and some of them are aimed directly at
the Earth.
The photons are sent out
at such an incredibly fast speed,
that
the ones which reach Earth travel over 93 million miles in under 8
minutes. They are basically tiny packages of sunlight, also
known as quanta - which is where the term quantum mechanics
comes
from.
Part 2- Converting Photons
into Energy
Once the photons reach
Earth, we must harness them in order to create electricity from them.
This is done through the use of photovoltaic
cells which react with the
photons. These PV cells are coated with a material - usually silicon in
most modern cells - which displays the photovoltaic effect.
The photovoltaic effect is
used to describe the process in which energy is created by certain
materials when they are exposed to solar radiation or sunlight. This
process was
first discovered by the French scientist Alexandre-Edmond Becquerel in
the
mid 1800’s. These PV cells are stimulated by sunlight and then produce
direct current electricity. However, this energy must still be made
useable.
Part 3- AC/DC
No, not the band. Most all
appliances and electronics use alternating
current or AC power, which
differs from the direct
current or DC power that is generated by solar
panels. In order to transform this DC power into AC power, it is
necessary to have a solar
power inverter connected to your solar panels.
This inverter allows the energy generated to be consumed, fed back into
the grid, or used to charge a battery depending on what type of solar
energy generating unit you have.
Part 4- Solar Energy
Consumption and Storage
Once the solar energy is
converted into AC power, it is possible to use this energy to
power
your home or business. If you have a grid tie solar system,
the
electricity you produce will be fed directly back into your local power
grid. When you are producing electricity, any energy you consume will
come directly from your solar system and any excess will go back into
the grid.
When you are not producing
electricity, then any electricity you consume will come directly from
the power grid. If you have an off-grid
solar system, then your system
will have a rechargeable battery in the loop, right after the inverter.
This battery is
charged by your solar cells and stores any excess energy, which
guarantees that you will always be using the energy you generate
yourself, and that you’ll
always have energy as long as you produce sufficient amounts.
How Does Silicon Produce
Energy?
Silicon is the most common
conductor used in PV cells nowadays, for several reasons.
The main
reasons lie in the extremely low price of silicon and the fact that
it’s widely available worldwide.
 However, pure silicon is
not an
excellent conductor due to its crystalline structure. A silicon atom
has 14 electrons in three different layers (or shells), with 2
electrons in the
first, 8 in the second, and 4 in the third layer.
This third layer is only
half full and the atoms always seek to fill up their layers with
electrons by sharing them with other atoms around them.
However,
because of the even number of electrons, each silicon atom will have a
full share, which leaves less room for free electrons to
go. When
energy
is added to silicon, some of these electrons break free and look for
holes left by other free electrons.
This movement of electrons
is what actually generates electricity. The photons strike the PV cell
and ideally, each photon will knock one electron free and send it
searching for a hole to fill, thus conducting electricity. Because
silicon has an even number of electrons, all modern solar cells use
impure silicon
as a way to free up extra electrons to conduct energy
better.
All solar companies have a
patented crystalline structure that they use in their own panels, and
these are made by adding other atoms into the silicon, although usually
only a few parts per million. The two main types of atoms that are
added to silicon to form solar cells are usually phosphorous and boron.
For more interesting and
useful information about the science behind solar energy, be sure to
take a look at the following sites:
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