Four Major Components
(This article is from Mr. Solar's
March 2001 newsletter)
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
Do you want to know how much power can be produced in your 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.
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 how these different components are used in systems**.
-Chest freezers are 9-22% more efficient than upright models.
-Using a pressure cooker cuts energy use by 50-75%.
-Small appliances and electronics account for 14% of average household energy
-The averaged air-conditioned home uses more than 2000 additional kilowatt hours
-In colder climates windows are responsible for 10-25% of a homes winter heat
Alone or "Cabin" Systems Solar: You need---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 too 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 bringing in the power lines, the initial
cost can be less. Some of the pros of this type of system are: The lack
of reliance on the utility, potential cost savings. Some of the cons of
this type of system are: Even though there may be 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 don't have utility power
for backup. ++++++++++++++++++++++++++++++++++++++++++
Tied System Solar (grid-tie): You need---Inverter---Utility
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.
Backup System Utility (off-grid) You need---Battery Charger---Batteries*Inverter---AC Loads
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.
Tied Battery Backup System with Solar (hybrid system):
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.
Check energy guide labels on all new appliances
purchased, this gives you the cost of energy used per year. Flow control faucets
can reduce the heating bill by as much as $86 per year. When on vacation, turn
off the hot water heater. Run only full loads in the dryer, and if possible, dry
two or more loads in a row to make use of heat already in the dryer.