Solar Rule Of Thumb....
I was wondering with so many variables is there a rule of thumb on how large of a solar system you need to keep your batteries charged so not having to run the generator. The factors I would includ...
Forum Discussion
KD4UPL wrote:
You just need to calculate watts-hours in versus watts-hours out.
When buying a panel go as big as possible. Anything less than 100 watts is a joke. The bigger the panel the cheaper it is on a watts/dollar basis. The best deals will be on panels in the 275 to 330 watt range. For these you will need an MPPT charge controller to match the output voltage to your battery bank.
Don't skimp on the panel or the controller. Get a big panel, get a controller large enough to handle a few more panels. A 60 amp controller will handle 2 or maybe 3 of the large panels.
Key difference. You may have a peak demand of 200w but if it's for 10hrs, you need a lot more than a 200w panel.
You can tell what size he will need or want until he assesses what he is going to use. If it's just the water pump and a single 15w light bulb for a couple hours, a 100w panel is overkill (of course, that would be a very minimalist lifestyle).
