Photovoltaic (PV) cells are made of
semiconductors such as silicon and they
convert sunlight directly into electricity.
A module is a group of cells
connected electrically and
packaged into a frame, commonly
referred to as a solar panel.
Light strikes the cell and a certain
portion of its energy is absorbed within
the semiconductor material, knocking
electrons loose, allowing them to flow.
By placing metal contacts on the
top and bottom of the PV cell, we
can draw that flow of current off for
external use. This current, along
with the cell's voltage (a result of its
built-in electric field or fields),
defines the power (or wattage) that
the solar cell can produce.
Silicon is a very shiny
material, which can send
photons bouncing away
before they've done their
job, so an antireflective
coating is applied to
reduce those losses. A
glass cover plate
protects the PV cells
from the elements.
Not every roof has the correct orientation to take
full advantage of the sun's energy. Solar panels
should ideally point toward true south, although
easterly and westerly directions can work too.
Most residential homes with solar panels are
connected to their local utility grid. This allows you
to buy power when you need it and sell it back
when you produce more than you use.
by state and city.
Your local utility
company may or
may not allow
your solar panels
to connect to
their grid. And
can vary greatly.
Reputable solar panel installers
like Verengo Solar utilize
special equipment to make
sure the power you're looking
to sell the utility company is
compatible with their own.
There are lots of factors involved in
determining whether installing a
solar system is worth the price.
For example, in a solar panel, if even just
one of its cells is shaded, power
production can be significantly reduced.