Solar strategy in the east
I'm from Illinois. Camping out in the AZ desert at the moment, I can see that solar is easy out here. Do the math, install it right, and you are golden. Camping in the eastern 2/3rds of the US, i...
Forum Discussion
BFL13 wrote:Wow - lets look at reality using your example. The 12V panel loses 7V or 7/21 of its power. So a 100W panel can only deliver 67% of its power with a PWM controller. The same panel with a good MPPT controller would lose only about 8% of its power.
Nerd here. When a PWM 12v loses voltage from 21 volts (12v panel) it still has plenty to be over 13v so amps don't suffer. MPPT (37v "24v" panel) makes its amps from voltage so it does suffer if voltage goes down.
What you're missing is that PWM can only charge at the panel rate and loses significant power due to the voltage drop. MPPT on the other hand coverts the amps and voltage of the panel (ie the watts) to the higher amps and lower voltage of the battery charge. Hence the battery charge amps with MPPT is higher than the panel amps. It's all about power conversion and both amps and voltage are part of the equation.
