EKO-EU Test Facilities
The EKO-EU test site is a state of the art reserach facility for ongoing internal and external product development and fundemental PV research.
The test site is equiped with the full range of thermopile radiometers, Si pyranometers, reference cells and spectroradiometers to monitor the different solar irradiance components respecively direct, diffuse and global. Year around data is collected to perform extensive analysis on PV modules for internal and customer reserach purposes.
PV Module performance testing
The performance of a PV module is measured at the factory under the so called Standard Test Conditions, described in IEC 60904. This is a convenient test method that can be integrated in routine production procedures. However, the indoor measurement of the PV performance at STC reveals the power production of the module at only one, particular measurement condition, as defined in the norm. So, these STC performance values do not automatically reveal the PV power production at the site-specific meteorological conditions. When using the PV module at higher latitudes and at relatively high temperatures the module label values might be misleading and might over-estimate the PV power production at this location. At the EKO-EU test site the performance of various PV modules is continuously monitored under outdoors conditions. A multi channel MP-160 I-V tracer system is used to measure I-V characteristics every 10 minutes.
At EKO-EU pyranometers can be re-calibrated side by side against a calibrated reference pyranometer. Both pyranometers can be either mounted horizontally or in a tilted plane and will be connected to a data acquisition system. For a period of a few days global radiation is measured based on 1 minute average values with a minimum of 300 datapoints. The calibration value of the subjected pyranometer is obtained by multiplying the sensitivity value of the reference pyranometer with the averaged ratio of the measured global radiation data. To improve the calibration accuracy and mimimize the measurement uncertainty several operating criteria are applied. The criteria for the operating conditions are indicated like ambient temperature, min. global radiation and min. solar elevation angle are applied to minimize the overall uncertainty in the calibration. The pyranometer uncertainty figure is statistically calculated based on a standard deviation of (1.96σ), which means that 95% of the measured global irradiance values agree with the reference pyranometer.