solar power calculations required.

[Qaisar Azeemi]

HI,

i want to run 100W load with solar Energy for 24 hours. sunlight here is available for 8hrs only. now how much watt solar panel that i should use and how much Capacity (AH) pb batteries are required for that purpose. can solar panel charge the batteries in day light when no sunlight is available? kindly give me formulaic calculations. and also give me the formulas used.

thanking you in anticipation.

Best Regards

 

[BradtheRad]

Using simple ballpark calculations...

Running 100 W for 24 hrs, means you need to store 2400 W-hrs.

If your battery is 12 V then it must continually provide 9 amps. Its capacity should be 2400/12, or 200 amp-hrs.
If your battery is 24 V then it must continually provide 4.5 A. Its capacity should be 2400 / 24, or 100 A-hrs.

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The type of battery...

A golf cart battery is among the best type of deep cycle battery to use in backup electrical systems. Its lead plates are made to endure harsh treatment (though you should avoid abusing a battery). This type is large and heavy, and may be larger capacity than you need.

A marine battery is second best but may be satisfactory since it is made for deep cycling and it will not be carrying heavy current. I believe there are 12 V type with a 200 A-hr ratings.

A car battery is third best because its plates are not made for deep cycling, but are made to deliver strong current all at once, then receive a rapid charge. You can use one if you have it on hand, although it will have a shorter useful life than a marine battery or a golf cart battery.

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You say you have 8 hrs to accumulate 2400 W-hrs. This requires 300 W continual charge during sunlight.

You'll need six 50 W panels. (Or five 60W panels. Or ten 30W panels. Etc.) Add 10 or 20 percent to make up for losses and inefficiency. The panels should all be the same make and watt output if possible.

If your battery is 12 V then the panels must put out 300 / 12, or 25 amps in sunlight.

If your battery is 24 V then the panels must put out 300 / 24, or 12.5 amps. You'll put two panels in a string. Multiple strings will be in parallel. Hence you'll use an even number of panels.

During the day, 100 W worth of panel output will be to operate your 100 W load.

On cloudy days you'll get a lower current output from the panels. If you wish to get through a cloudy day or two then consider using a greater number of panels.

Also remember the sun shines for fewer hours during winter, and is lower in the sky. You'll accumulate fewer W-hrs of juice. This is another reason to use a greater amount of panels.

 

[chuckey]

try :- https://en.wikipedia.org/wiki/Photovoltaics
Frank