There are
four major components to solar electric systems; Solar Panels, Charge Controllers,
Batteries and Inverters.All of these components are necessary to have a functioning
Solar Electric (PV) system.The solar panel is the basic building block of the
system.This is your battery charger. If you have several solar modules wired
together you have created a solar array. The size of the solar array determines
the amount of power or energy that will be produced. Your location is also a
factor in the amount of energy produced. If you live in Florida, Southern California,
or Texas you will produce more than if you live in Oregon, Maine or Maryland.
In general the closer to the equator you live your system will produce a larger
amount of energy. Do you want to know how much power can be produced in you
area. Check out our FAQ question "How much power will a solar module produce
at my location?" Charge controllers come in many different sizes and types.They
all basically do the same thing. The charge controller prevents the solar panel
or array from overcharging your battery. Batteries are the energy storage for
your system. Without batteries there is no way to store the energy your solar
panels produce during the day. Typically loads receive their power from batteries
instead of directly from the output of a solar panel. A solar panel produces
a high voltage that will damage electronics if loads are powered directly. A
common application for solar panels directly powering a load is water pumping.
Instead of storing energy you store water. This way you can pump during the
day and have water all night. Batteries will provide you with the energy you
need at night.The last major component is the Inverter. The inverter converts
the DC energy stored in your batteries and turns it into the AC power you use
in your home. Inverters are rated by wattage and the quality of their output.
You can use a 50 watt inverter that plugs into your car 12 volt outlet to power
a computer, or you could have a 4000 to 11,000 watt inverter system that powers
your home. These major components can be put together in many different ways.
Minor components like wire, disconnects,circuit breakers, and fuses are also
needed for a complete system. Now that you know what the major components are,
let me introduce you to you how these different components are used in systems
.
Stand Alone or "Cabin" Systems
Solar---Charge Controller---Battery---Inverter---AC Loads
or
Solar---Charge Controller---Battery---DC Loads
A Stand Alone solar system is just as it sounds. It is not connected
to the utility or other types of charging sources.This type of system is used
when utility power is not present and is to costly to bring in from the nearest
pole. If you have a shed set off from the house, a cabin in the mountains, or
a summer home by the lake that is without power this type of system can often
be very cost effective. When compared to bring in the power lines the initial
cost can be less. Some of the pros of this type of system are: The lack off
reliance on the utility. Potential cost savings. Some of the cons of this type
of system are: Even thought there maybe a cost savings over running utility
line, there can be a high initial cost. You have to know your loads and have
the system designed correctly since you dont have utility power for backup.
Utility Tied System
Solar---Inverter---Utility
This system is the newest addition to our site. The system utilizes
an inverter that does not require batteries. During the day, the power generated
is fed back into the utility. If you are producing more power then you are using
your meter can even spin backwards. Due to the simplicity of the system, it
has the lowest cost per watt. The downfall of this system is that when the utility
grid fails the system will shut down.
Battery Backup System
Utility---Battery Charger---BatteriesInverter---AC Loads
This is a system that does not involve solar power. This system
utilizing an inverter that has a built in battery charger. It will charges batteries
and hold them at 100% waiting for a power outage or a brownout. Your critical
loads will never see the power outage. Computers, home health equipment, and
lights will continue to operate when the utility grid fails. This is a system
that is great for areas where power is lost for short periods of time. The limit
on this system is the amount of battery capacity that you have. The larger the
batteries the longer your run time will be.
Utility Tied Battery Backup System with Solar
This system operates on the same principal as the Battery Backup
System. The difference is the addition of solar.The solar is used to charge
your battery bank. When the batteries are full the excess power is fed back
into the grid. In the event of an outage, your critical loads are powered by
the system, and the solar panels continue to charge the batteries. The benefit
of this system is that you have the ability to sell power back and have the
piece of mind that you critical loads will continue to operate. The drawback
is the cost per watt is higher then a Utility Tied System