Solar for newbies

[MountainDon]

Some nice equipment there.  I do have to wonder why the installer placed the batteries right there in front of the inverters and charge controllers to force one to walk on scraps of plywood on top of the batteries.  I am pretty sure that would not pass an NEC inspections. They could have placed one 24 cell string up the left wall and the other up the right wall so you could walk directly up to the equipment. Both the + and - ends of the string could be at the equipment wall and connect to a buss.

Especially do not try placing FLA (flooded lead acid) batteries directly below electronics like that. It'll rot the equipment.



RE the battery link above the system link.  They appear to be just another brand of AGM battery. AGM's are sealed (SLA) and have good points, but do cost more per amp-hour and may not last any longer than FLA.

[MountainDon]

There are two good online educational resources I like to recommend.

The Solar Biz  and  Northern AZ Wind & Sun.  Those links go to their resources index page. Both have been in business several decades each.

[NathanS]

So in order to run my fridge for 24 hours I need to get 36 amps in 6 hours

So I need my panels to give me ---36/6 = 6 amps every hour

24 volt panels are pretty common now.........and sold in watts.........P=V*I.......24v X 6amps = 144 watts of solar panel

But thats 24 volts and not 110... and the conversion takes power.........so lets add a bit of power to the panels to take out the invertor losses call it 180 watts the next size panel up

so thats awsome we get 6 hours times 8 amps...giving me 48 amps per day back into my batteries to power me over that 24 hours

I think you're accounting for the energy loss of the inverter, but not the extra energy required for going from 24v to 110v.

Ignoring the inefficiency of the inverter, if you need 36 amps a day at 110 volts, that would draw 36 * 110 / 24 = 165 amps per day from a 24 volt battery.

Trying to make the math even more simple.. if you need 1 amp at 120 volts, then you need 10 amps at 12 volts.


Someone correct me if I'm wrong.


I find the most intuitive thing to measure energy usage in is amps, but if you have stuff at different voltages you're going to need to do some conversions.