How Solar Systems Are Used

The following is a simple writeup intended to give you an overview.

There are two ways to utilize solar panels. Either by connecting to the
utility/power company's grid or to your own batteries.

The most common method is to connect the solar panels to a control box
that is connected to the utility power. As you generate power that
lowers your electric bill by supplying power to you with the result that
you use less power from the utility, and may even give you credit for
unused power. The utility company is your “battery backup.” But if the
power grid goes down so do you as you depend 100% on them to for
electricity. If you think that sounds counter intuitive it is because it is!



What I am mostly interested in is to store power in batteries so that
when power does go down I can continue operating. This also uses solar
panels but the control box is a bit different. Rather than connecting
you to the power grid it connects you to one or several batteries.



The same controller manages the power coming from the panel(s) and sends
it to the battery. It ensures that the battery is being charged properly
and is not over charged, it also ensure you don't over load it nor
deplete it.

The power from the solar panels are low voltage. This means that if you
want to run a normal appliance you will need to convert it to the 110V
your appliances runs on. For that you use an inverter. They vary in
capacity from a few watt (enough to run a small lamp) to thousands of watt.

The kinds of batteries you should use are called Deep Cycle batteries.
Unlike traditional car batteries these are ideal for the kind of
charging and discharging associated with this kind of use. Often Marine
batteries are dual function meaning they can be a used in a car or as
deep cycle batteries.

You can connect multiple solar panels to get more power just as you can
connect multiple batteries to store more power. A plan needs to be made
to match your budget with the capacity you want to get maximum
efficiency. A solar contractor can help work out the details.

A federal tax credit of 30% is available in 2016. Also, there are
financing available that will charge you from your monthly savings
preventing any cash outlays.


(Technical notes)

For the do-it-yourself'ers there are a number of factors to consider
such as total power load, cable lenghts and thickness, how high they run
above the roof and if in a pipe. The method of securing to the roof
(most common) without damaging your roof and create water damage. For
example, the satellite antenna installers damage more roofs than any
other profession. You need to carefully consider the different types of
batteries available for this kind of use. At the same time a properly
designed system can work for many years so it is a good idea to use or
consult with a professional.