Check string voltage across the temperature range against inverter limits.
Panel voltage rises as temperature falls, so the worst case for insulation and inverter rating is a cold sunny morning. String length must be set by that condition rather than by nominal ratings. Exceeding the inverter maximum input voltage destroys it immediately and voids the warranty, making this the single most safety-critical solar calculation.
Solar Array Voltage
Voc(cold) = Voc × (1 + |coefficient| × (25 − T_min) ÷ 100); string voltage = Voc(cold) × panels
Voc(cold) = Voc × (1 + |coefficient| × (25 − T_min) ÷ 100); string voltage = Voc(cold) × panels Panel voltage rises as temperature falls, so the worst case for insulation and inverter rating is a cold sunny morning. String length must be set by that condition rather than by nominal ratings.
Exceeding the inverter maximum input voltage destroys it immediately and voids the warranty, making this the single most safety-critical solar calculation.
This calculator takes 5 inputs: Panels in series, Panel open circuit voltage, Voltage temperature coefficient, Minimum cell temperature, Inverter maximum input voltage. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.