Which is better, Series or Parallel panels
In this situation, which is better, series or paralleled panels ?
Forum Discussion
pigman1 wrote:
I asked the same question of an engineer at Northern Arizona Wind and Sun as specifically applied to my 6 Kyocera 140W panels and Morningstar MPPT controller. He said that the parallel wiring was the most efficient in so far as partial shading of a portion of one or more panels or totally shading one or more panels for my installation. The down side is higher line losses and higher costs for heavier cabling.
This is correct: panels in series, current is limited to the panel in the most shade.
The math from what I've seen.
Two panels in series, Vmp = 18.1 volts, Imp = 4.47 amps.
Watts for full sun (Vmp1(18.1) + Vmp2(18.1))* 4.47 amps = 162 watts
Partial shading of one panel reduce totals watts by 60 to 80%
162 watts * 0.2( 80% reduction) = 32 watts
Watts in parallel full sun Vmp1(18.1)*4.47 amps plus Vmp2(18.1) * 4.47 amps or the same 162 watts
for parallel one in shade: Shaded panel Vmp(18.1) * 4.47 amps * 0.2(80% reduction) = 16 watts + 81 watts(non shaded watts) = 97 watts
