Is anyone successfully running an array at home with three series 60 cell panels (e.g. Rec Alphas) with a 150V MPPT in southeast California, southern Arizona / New Mexico, or southwest Texas?
I'm about to install one on my Ford Transit RV, but I had a sales guy warn about the higher irradiance we see in the desert southwest, so I got my local station to provide 10 years of data and sure enough we routinely hit 1200W/m2 (1.2 x STC) on some days of the year.
If the batteries were fully charged so the MPPT wasn't pulling any current from the array (commonly occurs) and was around noon on a 75-85F very cloudy day (e.g after a short rainstorm) so the panel was near ambient, if the clouds broke and the sun first appeared the math suggests the voltage could reach 44.1 x 1.2 x 3 = ~159V. And the specs actually allow for +/- 3% in panel voltage so technically it could be another 3% higher. On a cold freak hail storm summer day (we do get those every now and then) temps could even be 67F, so now the temp coefficient of Voc could add another 10 x 0.0024 = 2.5%.
But I don't care about the math as much as I care about real user experience, so does anyone living in Phoenix/Tucson, Las Cruces, or El Paso have a three series 60 cell panel array (e.g. Rec Alphas) installed with a 150V MPPT? If so, no issues releasing "the magic smoke" from your MPPT?
I'm fine if my MPPT shuts down when/if the above rare scenario happens, but I don't want to smoke it. If it's that close and others have had problems, I'd rather just used Rec N-Peak 2's that have a lower Voc.
I appreciate conjecture and other related feedback but I really want practical user experience.
Cheers.
I'm about to install one on my Ford Transit RV, but I had a sales guy warn about the higher irradiance we see in the desert southwest, so I got my local station to provide 10 years of data and sure enough we routinely hit 1200W/m2 (1.2 x STC) on some days of the year.
If the batteries were fully charged so the MPPT wasn't pulling any current from the array (commonly occurs) and was around noon on a 75-85F very cloudy day (e.g after a short rainstorm) so the panel was near ambient, if the clouds broke and the sun first appeared the math suggests the voltage could reach 44.1 x 1.2 x 3 = ~159V. And the specs actually allow for +/- 3% in panel voltage so technically it could be another 3% higher. On a cold freak hail storm summer day (we do get those every now and then) temps could even be 67F, so now the temp coefficient of Voc could add another 10 x 0.0024 = 2.5%.
But I don't care about the math as much as I care about real user experience, so does anyone living in Phoenix/Tucson, Las Cruces, or El Paso have a three series 60 cell panel array (e.g. Rec Alphas) installed with a 150V MPPT? If so, no issues releasing "the magic smoke" from your MPPT?
I'm fine if my MPPT shuts down when/if the above rare scenario happens, but I don't want to smoke it. If it's that close and others have had problems, I'd rather just used Rec N-Peak 2's that have a lower Voc.
I appreciate conjecture and other related feedback but I really want practical user experience.
Cheers.
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