What is the irradiance level called at Standard Test Conditions (STC)?

The irradiance level defined at Standard Test Conditions (STC) is 1000 W/m². This value is crucial in the solar energy industry as it serves as the baseline for testing the performance of solar photovoltaic (PV) modules. STC conditions are typically set at a solar spectrum of AM 1.5, a cell temperature of 25°C, and no shading or tilting of the modules.

Using this standardized irradiance level allows for consistent performance comparisons between different solar panels and ensures that manufacturers can provide reliable specifications. The choice of 1000 W/m² represents a realistic upper limit of solar radiation received on a clear day, making it an important benchmark for assessing and comparing solar technologies.