Tech & Energy
Solar String Sizing Calculator
Too many panels in series and cold morning Voc exceeds inverter max. Too few and you start clipping. Get the string length right.
Max panels per string
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- Min panels per string
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- Cold Voc
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- Hot Vmp
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FAQ
Why temperature matters? +
Voltage rises as panels get cold. A January morning string can exceed inverter Vmax even if it tested fine in July.
NEC requirement? +
NEC 690.7 requires using ASHRAE 99% temp data for Voc calcs. Standard practice is +25% conservative buffer.