Running Electricity Over Long Distance

[TheYogi]

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Originally posted by chrism
Sounds like a "1 battery per panel" ratio is a good idea.

Is there a reason why only 6v batteries instead of 12v? First thing that comes to my mind is that the 150w panels were 6v. Or am I totally missing something? Maybe they're just cheaper.

I'll have to go back to my old shop books for series-parallel diagrams but I'm assuming that' the purpose is either for the sake of redundancy or to build up your volts to a level that the 24v inverter needs?

On a rainy day like today (I'm in Pahoa at the moment), would I have enough sun/batteries to run a fridge, my laptop, catchment pump and a few cfl bulbs based on your 1st seven year system config? Oh man, the dreaded "dryer". Wasn't there a time when our parents dried cloths without an electric drier?? []

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Unfortunately, one battery per panel isn't quite how it's done. There's a reasonable amount of math involved in determining how many batteries you need. The key here is to determine how many watt hours your load list says you require. Once we have that, THEN and only then can we start to properly build your system.

Why are there 6 volt and 12 volt batteries? Because that's how they're made Let me detail batteries a bit for you:

Lead acid batteries: this includes your 12 volt, ~100 amp hour RV/Marine batteries. For PV, as soon as you need more than one RV/Marine battery on a 12 volt system, 2 on a 24 volt system, or 4 on a 48 volt system, you want to instead move up to golf cart batteries. These have half as many cells (so they're 6 volt) but have twice the capacity per cell, meaning around 200 amp hours. Golf cart batteries are a little more expensive but their lifespan (if properly taken care of) is about twice as long.

If you need more than 16 golf cart batteries then you'll want to look into L16's which are basically double size golf cart batteries. They're 6 volts, around 400 amp hours, and about twice the life span of typical gold cart batteries. WELL taken care of L16's can last 20 years! Poorly taken care of L16's can last 20 seconds.

Would you have enough sun/batteries on a day like today? That depends on a TON of variables Chris. It depends on everything from how energy efficient your appliances are to the size of your system.

Once we have your load list, we can proceed from there