The Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) from Kassel, Germany, and its European project partners of the Network of Excellence European Distributed Energy Resources Laboratories (DERlab) have developed standards and measuring methods for long term tests of solar modules.
The quality standard developed by the DERlab partners is based on standardized test procedures and data formats as well as evaluation services and uniform reports. Dr. Philipp Strauss, Division Director of Systems Engineering and Grid Integration at the Fraunhofer IWES and spokesman of the board of DERlab said, “For our measurements, we do not only examine the location specific yield, but also the influence that ambient conditions have on the module output.” In field tests, running in parallel, the researchers measure the solar modules under real conditions at the most diverse European locations. A further module serves as a reference and is stored in the dark.
The Fraunhofer IWES has developed the measuring card ISET MPP meter for the automated measurements, which should last at least a year. “Every 15 seconds, it records the short circuit current and the open circuit voltage as well as the current and voltage at the maximum power point (MPP) of the solar module”, explains Dr. Norbert Henze, Group Manager of Engineering and Measuring Technology at the Fraunhofer IWES. “In addition, it measures the irradiation intensity needed for the exact comparison, as well as the module temperature.” In a one minute cycle the measuring card captures the entire volt age/current characteristic. The measuring inaccuracy lies at much less than 1%.
This technology will be presented for the first time at EU PVSEC along with the company’s three phase, grid connected module-integrated inverter for high voltage solar modules. This inverter was developed within the project PV MIPS that is coordinated from Kassel and is funded by the European Commission (DG TREN).