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TO
FIGURE YOUR POWER REQUIREMENTS, you need to do some homework for
us--everyone's power consumption differs! Without your load
information, we cannot specify what components it will take for your
system.
These items and appliances are
listed with their hourly power requirements in terms of watts.
Figure out what you need, and multiply that by your hours of usage in a
day. WE'RE TRYING TO COME UP WITH THE TOTAL WATT-HOURS PER DAY
YOU NEED. For example, a 300 watt (120V AC) load for ˝ hour
consumes 150 watts--or for 3 hours would come to 900 watt-hours needed
for this item. If you cannot find your specific load requirement
on this list, look for an electrical rating sticker on your unit, or
contact the manufacturer.
*** AMPS X
VOLTS = WATTS ***
For
example, if it says 2 amps (@ 120V), the load is 240 watts per hour. Or,
a 4 amp load for 8 hours a day would come to 3840 watt-hours needed per
day. If you already know your daily power requirements,
click on "Map & Insolation Data"
to get an idea of the costs for your system. If you need some
assistance, click on the load evaluation
button which gives you an outline/worksheet to help ascertain your power
requirements.
YOU CAN USE YOUR
UTILITY BILL AS A GUIDE--usually the number of kilowatt hours used
per month is listed (a kilowatt-hour is 1000 watt-hours, a kilowatt is
1000 watts). If you divide the number of kilowatt-hours used by
the number of days of the billing period, then multiply that number by
1000, you'll come up with the average number of watt-hours per day you
use. The amount of power you use may shock you! This is why,
if you're considering going off-grid, it's crucial that you reduce
your electrical loads as much as possible
by using energy efficient lighting,
refrigeration units,
and by converting your heating loads to
natural gas, propane
or wood. A photovoltaic (PV) powered home might look like a
conventional home, but its electrical requirements are significantly
reduced by the use of energy efficient appliances, and by using gas for
all heating loads. |
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Remember, if you're only using a given load for a part of an hour,
divide that hourly total by the percentage of the hour you're using that
load. A 300 watt per hour load for ten minutes equals 50 watt-hours
total. The electrical load
information is most crucial;
without this information, there is a risk of under- or over-sizing
the system requirements. We don't want to sell you something that
doesn't meet YOUR SPECIFIC power requirements. If you have
questions or need help figuring out your loads, please do not hesitate
to
e-mail us or call 406 777-4321, or use the
load evaluation button and form to help figure your power
usage.
After you have ascertained your load information, multiply the
watt-hours needed per day by 1.3, to account for battery and inverter
inefficiencies. THIS IS THE ACTUAL POWER YOUR SYSTEM NEEDS TO BE MAKING
TO MEET YOUR LOAD REQUIREMENTS. Batteries and inverters are not 100%
efficient, so we refer to this as the "load correction factor".
With this figure, we can determine what size system, and what
components, are needed to meet your power requirements. Click on
the insolation map
to determine the amount of sun-power available for your area.
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IF YOU KNOW WHAT COMPONENTS YOU'RE LOOKING FOR…
PLEASE JUMP TO OUR
"COMPONENTS"
PAGE OR OUR "PRICING" PAGE!!!
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WHAT'S NOT SMART TO
DO WITH SOLAR….
There are definitely electrical loads that are NOT at all
cost-effective to power with solar electricity . These include: making
heat in any way (space heating, water heating, clothes drying, cooking)
and other large loads (air conditioning, refrigeration). It is generally
MUCH more cost-effective to power these loads with wood, propane, or
natural gas. NOTE: there are some
energy efficient refrigeration units available that are
reasonably powered by photovoltaics. Be certain you know your
manufacturer's (accurate) specifications. The wattage demands for
refrigerators and freezers may run from 540 watt-hours per day (for an
efficient unit) to upwards of 8500 watt-hours per day. That's a BIG
difference! We have additional information on
energy efficient and
propane refrigeration units |
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SUGGESTED SYSTEMS -
Map & Insolation Data |
After you have ascertained your
"adjusted watt-hours per day" required , using the power load
information, you can get an idea of what your power requirements
will cost when you click on our
Map & Insolation data in the U.S. By selecting
your zone location, we can determine the amount of sunlight that is
provided to your area--and, with your load information, determine what
components are necessary for your system.
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