HAIL TESTING OF PV MODULES: RESULTS OF AROUND ROBIN FOR HAIL GRAIN QUALITY DETERMINATION AND TESTING RESULTS OF DIFFERENT MODULE DESIGNS

摘要

For the qualification of PV modules in accordance with the IEC 61215 and IEC 61646 standards, the hail resistance test is mandatory. Chapter 10.17 of the standard describes the launching equipment and the measure-ment instrumentation, but is somewhat lacking in the definition of the hail grain quality. In fact, laboratories in Swit-zerland and Austria have found different results in testing hail impact resistance, in particular for building materials. The supposition was that the differences were mainly due to the ice quality of the hail grain. In this work a round robin was performed between three institutes in Switzerland and one in Austria in order to determine the quality of the hail grains. The hail grains were produced with three different production methods. The impact energy of the hail grain was measured with a load cell and with the modelling paste method. The round robin showed that the produc-tion method and the quality of the ice, such as the ice temperature of the hail grain, have a considerable influence on the impact energy, which varies up to 30%. In addition, in these studies five different PV modules designs were tested with hail grain diameters of 25 and 35 mm, a speed of 18 m/sec to 50 m/sec, an ice temperature of -4° or -20°C and an incidence angle on the module of either 45° or 90°. Impact positions and numbers were also varied. Damage to the modules was determined with electrolu-minescent imaging.