Solar Gen help please

You can probably find them for less if you shop it around but check this out.

Here's a better deal on the same specs. Biennopower has awesome customer service also.

 
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Here's a better deal on the same specs. Biennopower has awesome customer service also.


Nice, I knew camping world was pricey. Now lets do a little math. I just looked at the full size fridge I have here at the shop, the label says at 110-120V it draws 6.5amps. So a fully charged 300Ah battery can run my fridge for 46 hours, but a 100% power factor doesn't exist maybe 97% if your lucky so lets round it down to 44hours. Now what would you need to charge such a battery. Lets use these 325W solar modules each one can make 5.45Amp, with say 5 hours of peak power sunlight on average per day, with optimum exposure and orientation, my math tells me you would need about 12. Of course you would still need an inverter and or inverter charger.

 
Nice, I knew camping world was pricey. Now lets do a little math. I just looked at the full size fridge I have here at the shop, the label says at 110-120V it draws 6.5amps. So a fully charged 300Ah battery can run my fridge for 46 hours, but a 100% power factor doesn't exist maybe 97% if your lucky so lets round it down to 44hours. Now what would you need to charge such a battery. Lets use these 325W solar modules each one can make 5.45Amp, with say 5 hours of peak power sunlight on average per day, with optimum exposure and orientation, my math tells me you would need about 12. Of course you would still need an inverter and or inverter charger.

You missed a very important part of math, the battery is 12 volt, not 120 volt. Also you have have figure in some loss from the inverter.

So 6.5 amps of 120v = 65 amps of 12 volt. So now you are down to 4.6 hours of run time with no loss figured in. The good news is that a compressor fridge does not run all the time.

The panel you have listed is a 48v panel at the listed 5.5 amps. So at 12 volts that is 22 amps. For basic math figure you get about 5 amps/100 watts of solar at 12v at peak performance.

Always make sure you are talking about your amps in the same voltage. For example my 1500 watt toaster oven is 12.5 amps at 120 volts, but 125 amps at 12 volts. It remains 1500 watts though. In your case your fridge is 6.5 amps at 120 volts or 780 watts, no matter what amps or voltage it will always be 780 watts.

If you look at my previous post you will see some figures from what I use in my RV.
 
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You missed a very important part of math, the battery is 12 volt, not 120 volt. Also you have have figure in some loss from the inverter.

So 6.5 amps of 120v = 65 amps of 12 volt. So now you are down to 4.6 hours of run time with no loss figured in. The good news is that a compressor fridge does not run all the time.

The panel you have listed is a 48v panel at the listed 5.5 amps. So at 12 volts that is 22 amps. For basic math figure you get about 5 amps/100 watts of solar at 12v at peak performance.

Always make sure you are talking about your amps in the same voltage. For example my 1500 watt toaster oven is 12.5 amps at 120 volts, but 125 amps at 12 volts. It remains 1500 watts though. In your case your fridge is 6.5 amps at 120 volts or 780 watts, no matter what amps or voltage it will always be 780 watts.

If you look at my previous post you will see some figures from what I use in my RV.
So I was "only" off by a factor of 10. At least I never claimed I was an expert. Did I at least get the math on solar panels to charge the battery correct? The good news is with two of those 325W solar panels, you could almost run my fridge. Once you start adding up the cost of solar panels, racking, batteries and inverters, a small diesel or natural gas powered generator starts make a lot more sense.
 
So I was "only" off by a factor of 10. At least I never claimed I was an expert. Did I at least get the math on solar panels to charge the battery correct? The good news is with two of those 325W solar panels, you could almost run my fridge. Once you start adding up the cost of solar panels, racking, batteries and inverters, a small diesel or natural gas powered generator starts make a lot more sense.
Just those minor details ;)

With the solar panels to battery, again not figuring for loss, or voltage conversion loss, and using peak performance you would get 22 amps from each panel. To make math easy for me, if you had used 220 AH (amp hour) out of that battery, you would need 10 hours at 22 amps to refill it. If you have 2 panels it would take half the time, 4 it would take a quarter of the time.

As for running your fridge, you need 65 amps at 12v to run it so you would need 3 panels = 66 amps. Again at peak performance with no loss.

Yes, solar gets expensive quick and there is no "best" answer, each have advantages and disadvantages.

My RV has:
960 watts of solar (I make 55 amps at peak), about $1000
675 ah of AGM batteries (1/3 cost of lithium), about $1300
3000 watt hybrid inverter/charger, about $1500
100 amp solar charge controller so I can expand if needed, about $500
I have also have about $500 just in wiring and connectors to hook it all up

I also have a built in 5500 watt generator with a 30 gallon fuel tank.

Is solar extensive, yes. Is solar very nice, yes. Does my system do what I want it to, yes. Would I go with solar only, no.

For most of the year I run 100% on solar. If it is hot, I need my generator to run the AC. If we have cloudy days, or as the days get shorter in the fall I typically run my generator 1 hour in the morning and 1 hour in the evening. The charger in my inverter does put out 125 amps so it can do a lot of charging in those 2 hours. I typically run it while we are cooking to reduce the storage taken out of the batteries while charing at the same time.
 
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bgdawgrr

bgdawgrr

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Once you start adding up the cost of solar panels, racking, batteries and inverters, a small diesel or natural gas powered generator starts make a lot more sense.
It does, until you run out of fuel, or need reduced noise signature. ;)

I’d always suggest conventional genset as primary, with dual/tri fuel conversion first. Solar and even wind as auxiliary methods of power generation that will be more sustainable long term. Heck, if I had a stream, I’d play with tha for fun as well.

Beyond the likely zombie, solar flair, emp, alien invasion SHTF apocalypse scenarios, seismic events are number one on my list. If that big one happens, we likely to have weeks to months of power outage. No way I can store or acquire enough fuel for that. (Presume NG is shut down). Now, Mt. Rainer, Glacier Peak, et al erupting also falls into that category, but screws all those plans, cause, ya know..ash.:s0092:

I guess that’s why they say no matter how hard you try, you can’t cover everything.
 
Now, Mt. Rainer, Glacier Peak, et al erupting also falls into that category, but screws all those plans, cause, ya know..ash.:s0092:
Even some from the wildland fires we have really cuts into solar use. Remember just a few months ago when for 1-2 weeks you could not see 500 yards because of the smoke..... Well my solar worked about about 10% for most of that time.
 

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