New to Solar

NorthGuy

Re: New to Solar

newl wrote: »

He did have a plan indeed.

Sorry. Missed it.

That's a good plan. So, the generator will have to be run for some time. Apparently, OP wants this to be very low. Say, at the present size of the bank, it runs for 10 hours per year. Note that such a low run time is not because you have a lot of batteries, but mostly because you also had to buy a lot of solar panels to be able to chage this enormous bank.

Let's suppose we make the battery bank half the size of what it is now. In new situation, the generator will run more, say 50 hours per year. That's more money on the fuel and more noise. But, we saved $10,000 or more on battteries (and will save the same amount again every time we need a new bank), we saved lots of troubles associated with charging such a big bank. We also saved some money on panels. Was it worth it?

Now, let's suppose you have a bank, which is only 1/4 of the size that you suggested. Now we need much less money for batteries, they're much easier to charge and we do not have troubles with them any more. But now you have to run your generator for 150 hours per year. Is that a good idea?

vtmaps

Re: New to Solar

Stdyhand wrote: »

I am also calculating for roughly 4 days of capacity with a 50% discharge IF we ended up going that long with overcast.

When your battery bank is sized for so many days without sun, it means that your overnight discharge will be less than 10% of your battery capacity. That may be a problem when there are too many consecutive sunny days. Our host's battery FAQ explains that repetitive shallow discharges may cause lead dioxide clumping on the battery plates.

--vtMaps

Stdyhand

Re: New to Solar

I'll check out the FAQ page more because I didn't know this, but the math I did to determine the size battery bank I would need considers a 50% discharge. Discharging the batteries would be much easier with 3 kids than it would be to keep them recharged so I doubt that will be a problem. :P

I do have a target though for getting started. Right away I need to power a...

fridge
3-4 14w CFL's for about 5 hours each day (may go with LED, not sure yet)
29" LCD with satellite receiver
to charge a couple laptops

This seems reasonable to power considering what I'm using now, but it's amazing how much you can use when it seems like the power never ends. I don't really need to run anything else. If it weren't for the kids I'd only care about keeping the food cold and thats it.

Stove, heating, and water heater will be by propane or wood stove. I may run a washer on a generator but I'm still reading about the effects this may have on a generator. I wont be using a dryer anymore and I've already given up using the one I got.

NorthGuy

Re: New to Solar

Stdyhand wrote: »

fridge
3-4 14w CFL's for about 5 hours each day (may go with LED, not sure yet)
29" LCD with satellite receiver
to charge a couple laptops.

That's not 13kWh/day. This is more like 5kWh/day or less. 400AH @48V would be a reasonable amount of batteries. With some creativity, you can get away with less.