Instructions / Assembly

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System Sizing: Step 1 - Determine Consumption
To determine the total system size you must first calculate your consumption in Watt hours (Wh) per day.
Lighting
If you have four 15W LED lights (actual wattage not equivalent wattage) that you plan on running for 8
hours per day, you would take the wattage of each bulb, multiply it by the number of bulbs and multiply
that by the number of hours of run time per day.
4 bulbs x 15 W/bulb x 8 hours/day = 480 Wh/day
Misc. Electronics
If you want a system to power your laptop for 6 hours per day plus a microwave oven for 10 minutes per
day you would first need to determine the wattage of each device. This information can usually be found
on the device or approximated with the help of an internet search. Let’s assume that the laptop consumes
65W and the microwave oven consumes 800W. Multiply each device’s wattage by its run time and add
the two numbers together.
1 laptop x 65 W/laptop x 6 hours/day = 390 Wh/day
1 oven x 800 W/oven x (10/60) hours/day = 134 Wh/day
390 Wh/day + 134 Wh/day = 523 Wh/day
Battery Charging
If your plan is to keep a battery bank charged, first add up the Amp hour (Ah) capacity of all the batteries
in your system, then multiply by the battery voltage to get watt-hours. The Ah capacity is usually shown
on the side of the battery. For example, an RV with two 80Ah 12 volt batteries would have a 1920 Wh
battery bank. Most batteries can only discharge 50% of their Wh capacity so only 50% of the total Wh rat-
ing needs to be fed to them to bring them to full charge. In this case that would be 1920 divided by two,
equaling 960 Wh.
2 batteries/day x 80 Ah/battery x 0.50 x 12 V = 960 Wh/day
Watts vs. Watt hours
Keep in mind that Watts is an instantaneous power measurement, not to be confused with Watt hours,
which is the actual energy consumption. Watts must be multiplied by estimated run time to determine en-
ergy consumption. A good analogy would be speed vs. distance. Watts are equivalent to speed, where
as Watt hours would be the distance. In order to determine how many panels are needed you need to
know the “distance.”
GS-100+KIT EXPANDABLE PHOTOVOLTAIC
POWER GENERATION SYSTEM
CONFIGURATION MANUAL Rev. 140304
Valid from Sep. 2014