Power Rating Measurements According to IEC61853-1

For each set of conditions (irradiance between 100-1100 W/m² in 100 W steps and temperature of 15, 25, 45, 50, 75 °C) according to IEC 61853-1, an I-V curve of PV module is measured. The temperature coefficient at 1000 W/m² is determined in addition from measurements between 15 and 75 °C in 1 K steps.

Additional to the accurate measurement of the power at STC, the behavior of the modules at different ambient conditions is important. For the power rating measurements, the modules are characterizedat different irradiance and temperature conditions. This accurate power rating measurements in accordance to the standard allows a comparison of the measured module type to other module types as well as to the current state of the art. Furthermore, power rating enables precise yield prediction for each location worldwide.  

The following table shows the matrix of measurements conducted during a power rating measurement at CalLab PV Modules. Measurements required by and defined in IEC 61853-1 are marked in dark green in the matrix. Measurements additionally made by CalLab PV Modules are marked in light green. The following specific conditions are marked additionally: STC (standard testing conditions), LIC (low irradiance conditions), HTC (high temperature conditions), LTC (low temperature conditions) and NOCT (normal operating cell temperature).

Based on hundreds of power rating measurements performed yearly, we are able to provide benchmarking for different module technologies. As an example, the following graphs show the expected range for low light behavior and temperature coefficients (green area) based on measurements performed at CalLab PV Modules and the deviation from manufacturer data sheets.