Photovoltaic Systems - Clean Electricity From the Sun
As people search for alternatives to fossil fuel energy, solar
energy emerges as one of the cleanest and most practical sources
of electricity. Solar panels can be installed on rooftops or any
area that receives a lot of sunshine. The solar panels consist
of a photovoltaic system that converts the energy of the sun
into electricity. The word Photovoltaic is a conjuction of the
old Greek word "Photon" meaning light and Volt, the force that
makes electrons move
Photovoltaic systems have existed since the 1950s but only in
recent years has the technology matured to the point of making
it a viable alternative to power utilities. Indeed, most solar
systems do not replace the utility company instead they work in
conjunction with it to produce extra electricity that can be fed
back into the grid.
One of the main problems with solar power is storing it for use
during non-daylight hours. Batteries can be used but they are
expensive and have a limited life span. As an alternative,
excess solar electricity can be fed back to the power utility
company for a credit, and then power can be drawn when needed.
In a sense, the utility company becomes the storage device.
Most municipalities have legislation requiring power utility
companies to accept electricity produced by solar panels or wind
turbines. This system benefits everyone "there is less
dependency on fossil fuel power plants" and electricity costs
are reduced for owners of photovoltaic systems.
This is called net-metering, the specifics depend on your
location and utility company. A disadvantage of these grid
connected systems is that there invertors disconnect in case of
a power faillure. This is a quite logical demand from the
utility companies point of view. Their engineers have to know
for sure that the grid they are working on is really dead. But
from our point of view it can be a nuicance. The solution is a
grid connected system with battery backup.
Photovoltaic cells produce electricity by using specially
treated materials such as silicon that convert light into power.
They can be of almost any size and are suitable for providing
electricity for small items such as calculators or watches right
up to complete industrial complexes. Because they can be wired
together, an array of solar cells can produce enough electricity
for residential or commercial needs.
The main requirement, of course, is sunlight. This makes solar
power most practical for southern areas such as California and
Arizona. But it can also be used in more northerly areas as a
backup power system. As the technology advances, photovoltaic
cells are able to produce usable amounts of electricity