Solar power

haas2418

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I have two 100 watt solar panels and 4 25 watt solar panels I got from harbor freight . The 4 panel set comes with everything you need to charge batteries and control box that allows you to change you phone and other electronics. I also have a 7000 watt inverter I got off Amazon that is a pure sign inverter so it will not hurt your electronics. We live up in the mountains and have been just fine when we loose power. Also we use it when we are camping.
 

Leveraction44

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I have two 100 watt solar panels and 4 25 watt solar panels I got from harbor freight . The 4 panel set comes with everything you need to charge batteries and control box that allows you to change you phone and other electronics. I also have a 7000 watt inverter I got off Amazon that is a pure sign inverter so it will not hurt your electronics. We live up in the mountains and have been just fine when we loose power. Also we use it when we are camping.
7000 watt inverter is a pretty big inverter. Does it have a 240 volt output? How much battery capacity do you have? I have a 3000 watt inverter on order with a 3000 watt-hr battery. With my present solar panels, that is about as much battery as I could charge on an average day.
 

haas2418

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I use 4 deep cell boat rv batteries. 7000 watts is max with a constant 3500 watts and yes I can run 240 but if you are planning on running your camper off grid you need to add up how many watts you need . A coffee maker needs from 900 to 1100 watts by it self not to mention you need clean power so I went with a pure sign inverter not a modified inverter.
 

wnchstrtnfldvlle

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So if I understand correctly,
I was looking at an 800 watt system (Renogy) that includes everything but the inverter and batteries. That just tells me that the system will provide 800 watts of charging power, ideally, regardless of the number of batteries correct? I get that the rate of charge may not be as efficient or quick.
Thanks for any input.
 

Mark Walker

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So if I understand correctly,
I was looking at an 800 watt system (Renogy) that includes everything but the inverter and batteries. That just tells me that the system will provide 800 watts of charging power, ideally, regardless of the number of batteries correct? I get that the rate of charge may not be as efficient or quick.
Thanks for any input.
Make sure that your inverters are compatible with your batteries, or the system will be pretty much useless...there are deals out there with obsolete inverters, that won’t work with newer batteries, so buyer beware...I have an 9 kw off grid system on my house, I didn’t not install all the stuff on my house, but have talked quite a bit to solar contractors over the years
 

haas2418

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So if I understand correctly,
I was looking at an 800 watt system (Renogy) that includes everything but the inverter and batteries. That just tells me that the system will provide 800 watts of charging power, ideally, regardless of the number of batteries correct? I get that the rate of charge may not be as efficient or quick.
Thanks for any input.
 

Leveraction44

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A big inverter is great, but often times a system is more limited by the amount of energy in the batteries and your ability to recharge them.

I know that I do not have enough battery capacity to run a large 240 volt load for very long. So I just know I am not going to even bother with that. So no electric stove top, oven, clothes' dryer, central air conditioning, ..

Take a small 120 volt electric room heater. It will probably draw about 1500 watts - similar to a hair dryer. So in just 2 hours of use, it has consumed 3000 watt-hrs of energy.

A nominal inverter efficiency is about 85%. So 3000/0.85 = 3520 watt-hrs. That is the minimum battery energy needed. One common battery size used is a 12 volt, 100 amp-hr battery. You would need at least 3 of those, assuming you could draw 100% of their energy. Good luck with that.

Then you would need enough solar panels to recharge the batteries. Say with 6 hours of good charging sunlight. You need to put 3520 watt-hrs of energy into your batteries. 3520/6 = 590 watts. That is the average power you would need to put into your batteries from your panel array over the 6 hour period.

But the rating on the panels are for ideal conditions. You will not have those. Also, getting the power from the panels into the batteries is not 100% efficient. This all means that your solar panel probably needs to be rated closer to 800 watts. If you used 100 watt panels, you would need 8 of them.

That is a lot of batteries and solar panels needed for just 2 hours of a fully loaded 1500 watt inverter.
 

Leveraction44

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I see most solar gens as a last ditch resort in case the grid power is down, and you have ran out of fuel for your primary electrical generator.

At that point you had better be picking with care, after much thought, which electrical loads you want to run with your batteries.

Here are a few I think deserve your consideration.

Refrigerator - while it has food
Batteries for flashlights, cell phones, 2-way radios, etc..
Ceiling fans
A few LED lights
Alarm system
Outdoor motion Lights
CPAP
Microwave for brief periods if no other means of cooking

What would you add to that essential list?
 
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