Solar Panel Voc-MPPT?
Wondering if there is any relationship between measured Voc and MPPT performance with a 24v panel. My 12v panel has a Voc rating of 21.9 and Isc of 8.2, but I often see 8.2ish when Voc is only 20....
Forum Discussion
Salvo wrote:
MPPT gains over pwm are in the 8% region when battery is held between 12.0 and 12.4V. What do you think the gain becomes when battery is at 13.0V?
What part of the calculations in my previous post do you dispute? You like to fixate on the reduced performance at extreme elevated temps yet reject the performance figures obtained at reasonable operating temps.
It would be very informative if a person of your obvious knowledge and experience would present an even-handed comparison of both systems, pros and cons, so that people (especially new to the game) would have a better understanding of why and when to choose one or the other.
There are many things to consider other than initial cost or hype. For me, panel real estate was limited to a closely defined footprint which I found only available in a 24-volt panel at the power level I wanted. Kyocera 135w 12-volt panels weren't available at the time and I would have only had a 270w system. The $200 extra I spent on the MPPT controller "bought" me an additional 100 watts in the two 185w panels I ended up with. Not a bad trade in my book.
