This article explains how to perform a current correction for irradiance in areas with higher-than-normal irradiance values (greater than 1000W/m²). High-altitude areas typically experience irradiance values greater than the PV module STC, since the air is thinner.
Exceeding the Isc and Imp values on the TS4 datasheets will impact the warranty and future RMAs. TS4 datasheets are located in the Tigo Downloads section.
Here is the formula (stay with us; it matters!) and the process for adjusting module Isc for areas with greater than 1000 W/m²:
Where:
- Isc (STC) = Short-circuit current at STC (module datasheet)
- G = Current irradiance level (W/m²)
- GSTC = Standard test irradiance (1000 W/m²)
Using the Formula
- Determine Isc: Check the module's datasheet for the short-circuit current rating
- Measure or Estimate Current Irradiance (G): Identify the irradiance level in W/m².
- Apply the Formula: Substitute the values into the formula to calculate Isc.
Example Calculation
-
Given:
- Isc (STC) = 8A (from the datasheet)
- G = 1200 W/m²
- GSTC = 1000 W/m2
- Calculate:
So, for this location with an irradiance value of 1200 W/m², the adjusted Isc value is still within specifications for all TS4's using this specific module Isc.
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