Solar fuseing, confuseing
Were installing a Renogy 400 watt solar system on our fith wheel. We stay on our property about two months in the summer up near Canada in Washington.Anyway this is the kit I bought. Mind you I'm comp...
Forum Discussion
Back to PWM vs MPPT for 12V panels.
From the above chart at 120F panel temperature the panel voltage would be 90%. Add 3% for wiring loss and 5% for MPPT loss (very reasonable numbers) and the 18V panel voltage is 14.9V at the battery. In the meantime Isc is 103%. I suspect a good MPPT controller would have already switched to PWM mode. With higher panel temperatures well… But if camping in the Colorado Mountains or cooler WA temps PWM would have an advantage.
Given the higher MPPT cost it’s reasonable for most campers to use PWM for 12V parallel panels.
My reasons for choosing 24V panels vs 12V panels considered a number of other factors. Basically for a larger system I got more panel watts/$ and more watts/roof sq foot. There were a number of other factors for my choices. Since my 2014 cost was $100 more for MPPT vs an equivalent PWM system I choose MPPT.
From the above chart at 120F panel temperature the panel voltage would be 90%. Add 3% for wiring loss and 5% for MPPT loss (very reasonable numbers) and the 18V panel voltage is 14.9V at the battery. In the meantime Isc is 103%. I suspect a good MPPT controller would have already switched to PWM mode. With higher panel temperatures well… But if camping in the Colorado Mountains or cooler WA temps PWM would have an advantage.
Given the higher MPPT cost it’s reasonable for most campers to use PWM for 12V parallel panels.
My reasons for choosing 24V panels vs 12V panels considered a number of other factors. Basically for a larger system I got more panel watts/$ and more watts/roof sq foot. There were a number of other factors for my choices. Since my 2014 cost was $100 more for MPPT vs an equivalent PWM system I choose MPPT.
