2655 N. Highway 89
Chino Valley, AZ 86323
ph:928-636-2201 fax: 928-636-2015
System Sizing Worksheet
The first step to sizing your solar
electric system is to determine your average daily power consumption (expressed
in watt hours per day). By using the following worksheet you can keep track of
each appliance and light you use, and the amount of time you use it. Remember,
be as accurate as possible, and consider ways you can conserve power. The
number you arrive at will determine the size system you will need. If you have
any difficulties with this worksheet, or want some design assistance, please
send us your worksheet. We will contact you as soon as we
recieve your worksheet and contact information.
1. Choose the appliances you use in the spaces provided.
If you use one that is not listed, enter it in the spaces provided.
2. In the second column enter the watt usage
of each appliance. Most appliances have a power tag on the back with this
information, if there isn't one, use the estimates provided on our
power usage chart. A useful formula
for this step is: Amps x Volts = Watts.
3. In the third column write the number of hours per
week that each appliance and light will be used. For lights, add up the number
of hours each type of bulb is on. For example, if you have two 60W bulbs on 3
hours each day, write down 42 hours. Remember that some appliances are only
used for a few minutes at a time, such as garage door openers or microwaves.
Also, keep in mind that some appliances will be used more or less according to
the season (ex: fans). Generally, we size a system according to winter usage,
as during the summer months increased power usage is usually offset by an
increase in the number of peak sunlight hours. This means you should only
include either your heating source OR your cooling source in your calculation,
as it is unusual to have both heating and cooling running at the same
4. Multiply the wattage of the
appliance times the hour per week it is used. This gives you the total amount
of power that particular appliance uses.