I'm trying to find out if I can run an appliance of mine can off the grid, completely on solar power and a battery. The appliance uses 4.91 amps and uses 110 volts on the power cord. The solar panel produces 45 watts of power. The battery is a 12 Volt, 35 Ah Sealed Lead Acid Battery. Now, I live in sunny FL, so sunlight shouldn't be an issue as it is sunny most of the time. Will a single solar panel and battery be able to run it 24/7, without fail? Meaning it must be able to run even when it dark out, cloudy, etc. If my setup won't work, how many solar panels and batteries will I need? Thank you in advance for your answers and advice.

  • \$\begingroup\$ The stack exchange websites are question and answer style and are not a general forum. More particularly, the stack is for design issues and the details involved in electrical engineering. You'd be better served at a DYI or Solar power forum. I will note that 110 V * ~ 5 A = 550 W and your solar panel is only 45 watts. \$\endgroup\$ – placeholder Sep 5 '14 at 13:53
  • \$\begingroup\$ Noting that the appliance needs 540W at least, there is a pretty good answer, explaining the issues and a methodology, already at Powering 10watt light bulb for 24 hours using solar power \$\endgroup\$ – gbulmer Sep 5 '14 at 18:52
  • \$\begingroup\$ What is the appliance, an air conditioner? \$\endgroup\$ – Matt B. Sep 5 '14 at 19:53

4.91 amps at 110VAC is a power of 540 watts so no-matter how long a day it shines this won't work because average power in should exceed average power out by a few percent to account for conversion losses.

Your solar panel produces only 45 watts of power.

Now maybe you mean your appliance takes 4.91 amps from a 12V dc supply - this equates to a power of 59 watts and still you have a sizable deficit. Maybe your appiance uses a 5V supply at 4.91 amps? This is a power of 24.6 watts and I can see that with a little bit of clever design (sun tracking solar panel maybe) and a decent battery to power it thru the night) that this might work.

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    \$\begingroup\$ I downvoted you simply because this question doesn't belong here. Why don't you try to contribute some of your time to maintaining this site pruning these sorts of question out instead of fostering them? \$\endgroup\$ – placeholder Sep 5 '14 at 13:56
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    \$\begingroup\$ @placeholder I disagree with you on all points in your comment. \$\endgroup\$ – Andy aka Sep 5 '14 at 14:01

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