Solar Costs - MPPT vs PWM
The continued lower price of the larger panels has now dropped the MPPT costs just below PWM for a larger RV solar setup. SolarBlvd Cynergy 3x$200 250W panels 750W $600 SolarHome Morningstar MPPT ...
Forum Discussion
I am not on solar until next April so all I can do is look at what I got, when I got it, on solar to the end of September this year, and in previous seasons. We only camp doing solar mid-April to end Sep. Winter camping Oct to mid-April is all gen /charger 50-90s and get back to 100% at home routine.
I always had the inverter doing high amps draw after solar wake-up so never saw what Jim is reporting. All I did see what that lousy 13.5 amps in July/August instead of the 15.5 I got in April/May, compared with the 14.5 I would have got with PWM the whole time. You could call it a wash for amps I suppose, sort of.
Turns out that was to do with panel temps when I deployed my IR temp gun at the under-side of the panel and did the math. Fact is I would do better for amps if I had the same 230w of solar panels but in 12v form and PWM so I would get 14.5 most of the "season" instead of 15.5 a short part of the time and 13.5 the longer part of the season. I sure would not get so annoyed seeing that 13.5 instead of 14.5 and would soon forget about any 15.5 magic stuff. Depends if you are a half empty or half full kind of guy I suppose.
However the money doesn't work out for that, so it is cheaper to lose that 1 amp most of the season than to pay the extra for the 12w panels instead of the cheaper 24w panel--but only thanks to the Eco-W being $102 instead of $300+ like the other MPPTs.
Which is the whole point of this thread's topic. You have to juggle a bunch of things that apply to you. Some other guy may have a different answer for how it all applies to him.
I always had the inverter doing high amps draw after solar wake-up so never saw what Jim is reporting. All I did see what that lousy 13.5 amps in July/August instead of the 15.5 I got in April/May, compared with the 14.5 I would have got with PWM the whole time. You could call it a wash for amps I suppose, sort of.
Turns out that was to do with panel temps when I deployed my IR temp gun at the under-side of the panel and did the math. Fact is I would do better for amps if I had the same 230w of solar panels but in 12v form and PWM so I would get 14.5 most of the "season" instead of 15.5 a short part of the time and 13.5 the longer part of the season. I sure would not get so annoyed seeing that 13.5 instead of 14.5 and would soon forget about any 15.5 magic stuff. Depends if you are a half empty or half full kind of guy I suppose.
However the money doesn't work out for that, so it is cheaper to lose that 1 amp most of the season than to pay the extra for the 12w panels instead of the cheaper 24w panel--but only thanks to the Eco-W being $102 instead of $300+ like the other MPPTs.
Which is the whole point of this thread's topic. You have to juggle a bunch of things that apply to you. Some other guy may have a different answer for how it all applies to him.
