Price of Solar! WOW
Unbelievable how low panel prices are. Solar Blvd has some 250W panels down to just .60/Watt! I'm getting ready to pull the trigger on my Solar project but might wait & see where the prices go. I l...
Forum Discussion
I've never been comfortable comparing PWM and MPPT. Use 24V panels on PWM? - nope. Use 2 12V panels in parallel on MPPT? - nope. Us 2 12V panels in series on MPPT? - questionalble.
An 18V 12V panel loses the power of 18-14.8=3.2V * the Imp. While MPPT has to convert the higher voltage to a lower voltage and from the MS manual the larger the panel vs battery differential (12V batteries being the worst) the more the controller losses.
PWM has to use (from a practical standpoint) a combiner box and larger wire to the controller, as in higher cost. While serial MPPT panels have less wiring cost.
Panel mounting costs? MPPT panels are heavier while PWM would use more and lighter panels for equivalent wattage.
Roof space? And here is the big biased item on these boards. PWM allows the use of smaller panels to work around AC's so mount them 1" above the roof. I've talked to and taken pictures of several people that have raised panels. One in Deep Creek Alaska of all places! My larger heavier MPPT panels will be mounted 6" above the roof and I estimate I'll have summer time shadows on the panels before 6AM and after 6PM regardless of rig orientation.
PWM allows (or did allow) the use of a lower overall cost but the Eco Worthy controller seems to be closing the gap)
So I waited before taking the plunge and hopefully it's "Do it right the first time". Which of course is unlikely to happen. I can only speculate what I'll learn vs reading about what other posters have learned.
Let the fun begin!
An 18V 12V panel loses the power of 18-14.8=3.2V * the Imp. While MPPT has to convert the higher voltage to a lower voltage and from the MS manual the larger the panel vs battery differential (12V batteries being the worst) the more the controller losses.
PWM has to use (from a practical standpoint) a combiner box and larger wire to the controller, as in higher cost. While serial MPPT panels have less wiring cost.
Panel mounting costs? MPPT panels are heavier while PWM would use more and lighter panels for equivalent wattage.
Roof space? And here is the big biased item on these boards. PWM allows the use of smaller panels to work around AC's so mount them 1" above the roof. I've talked to and taken pictures of several people that have raised panels. One in Deep Creek Alaska of all places! My larger heavier MPPT panels will be mounted 6" above the roof and I estimate I'll have summer time shadows on the panels before 6AM and after 6PM regardless of rig orientation.
PWM allows (or did allow) the use of a lower overall cost but the Eco Worthy controller seems to be closing the gap)
So I waited before taking the plunge and hopefully it's "Do it right the first time". Which of course is unlikely to happen. I can only speculate what I'll learn vs reading about what other posters have learned.
Let the fun begin!
