Windy Nation Complete Off-Grid Solar Kit - Manual (Page 19)

Complete Off-Grid Solar Kit Manual
Revision 2.0
• Clean the glass surface of the solar panel when necessary. Always use water and a soft sponge or cloth
for cleaning. A mild, non-abrasive cleaning agent can be used to remove dirt.
• Check the electrical and mechanical connections every six months to verify that they are clean, secure
and undamaged.
• Inspect the solar panels and make sure the surfaces are free from dust, dirt, and other debris; clean with
a wet cloth or glass cleaner if necessary.
• Check to make sure all structural components, mechanical fasteners, and electrical connections are
secure, clean, and corrosion-free.
• Check and maintain the battery electrolyte levels at regular intervals as per the battery manufacturer’s
recommendations if flooded wet cell lead acid batteries are used.
• Check and replace damaged components if necessary.
7.2 F REQUENTLY A SKED Q UESTIONS (FAQ)
1. What size battery should I use?
The battery size depends on how much power storage your system needs regardless of how much
generation capacity you have. You can have ten 100W solar panels charging a 50Ah battery or you could
have one 100W panel charging 1000Ah of batteries. The more panels, the faster the batteries will charge
and when the battery bank is fully charged the charge controller will prevent over charging.
Each 100 Watt solar panel is capable of charging up to a 125 amp hour 12 volt battery under normal
conditions. Two 100 Watt solar panels wired for 24 volt battery charging are capable of charging up to a 125
amp hour 24 volt battery bank.
2. What size inverter should I use with my solar panels?
In an off-grid battery backup system, the inverter is connected to a battery bank and the panels feed power
into the battery bank through a charge controller. Since the inverter isn’t directly connected to the panels, you
can use any size inverter you want as long as it is compatible with your battery bank and the devices you
plan to power. You can have 10kW of solar panels in the same system as a 450W inverter or you could have
one 100W panel in the same system as a 7kW inverter. The size of the inverter just limits the size of the
devices that your system can power, which affects how quickly the battery bank is drained.
Inverter size has nothing to do with panel count.
Inverter size has almost nothing to do with the power output of the solar panels. The DC to AC inverter is
connected directly to the battery and, therefore, is powered by the battery bank (the solar panels charge the
battery). Any size inverter can be connected to the battery bank as long as the battery bank is suitably sized
for the inverter.
You could have 1000 Watts of solar connected to your battery bank and only use a 100 Watt inverter. Or you
could have only 100 Watts of solar connected to the battery bank and have a 1000 Watt inverter.
Inverter size depends on the power requirements of the loads you will run. For example, if you are only going
to use a 100 Watt light bulb, then a 150 Watt inverter will easily provide the power. But, if you want to run a
1500 Watt vacuum cleaner, then you should get a 2000 Watt inverter.
3. Are the solar panels included in my kit 12 volt, 18 volt, or 24 volt solar panels?
Without going into detail, the Maximum Power Voltage (abbreviated V
pm
) of a solar panel should be rated at
about 1.5 times the nominal battery voltage. For example, a solar panel used for 12 volt battery charging
needs to have a V
pm
of about 18 (1.5 x 12 = 18).
The Windy Nation 100 Watt Solar Panels included in these kits have a V
pm
of 18. Therefore, these solar
panels are typically referred to in the solar industry as “12 volt solar panels” because they are designed for
12 volt battery bank charging.
A solar panel designed for 24 volt battery bank charging needs to have a V
pm
of about 36 (24 x 1.5 = 36).
When two solar panels with a V
pm
of 18 are wired in series, the two V
pm
‘s of each solar panel add together.
Therefore, two Windy Nation 100 Watt Solar Panels wired in series have a V
pm
of 36. The 24 volt wiring
diagrams shown in Section 5 show how to wire two solar panels in series for 24 volt battery charging.
Therefore, we can say that two Windy Nation 100 Watt Solar Panels wired in series is a “24 volt solar panel”.
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