Monday, Feb 09, 2015 at 16:42
Hi Kirko
As Jon has suggested connecting the similar panels in series has some advantages
[a] less voltage drop for the same sized cables
actual current is only that of one panel from the panels to the regulator
[b] you will get more output from the panels in overcast conditions
[c]They will be better able to give max possible output @either very HOT or very cold panel conditions
[c]Under the right conditions, you will harvest near the combined panels rated output
All of the above require a quality MPPT controller which must be able to handle the combined OC voltages of the panels
[if each panels OCV is 21 V then it must be able to handle a min. of 42V]
One of the disadvantages is shading of one panel can have a severe effect on output, unless Bypass diodes are fitted at each panel's terminals
PeterQ
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