E.ON has recently conducted a series of 600 PV system tests. While the results have not been officially published yet, first evaluations clearly show that the systems’ main deficiency are improperly installed cables or the wrong cables altogether.

In 2015, the German energy supplier E.ON started offering clients the new service of checking their PV installations. The demand is high, so that until today more than 600 tests were run. In cooperation with the Fraunhofer Center for Silicon PV (CSP) in Halle and the Center for Applied Energy Research (ZAE) in Bavaria, E.ON has now started working on a study. The goal is to identify and record all deficiencies in an aggregated form, so that statements can be made on frequencies and distributions – a goal that can easily be reached with such strong partners.

The Fraunhofer Center for Silicon Photovoltaic (CSP) is a long-time supporter of the energy company in the quality and reliability assessment of modules and plants. The research facility in Halle (Saale) will cover the characterization of modules, components and materials during this study.

Roofs of all sizes tested all over Germany

“Our experts were in use on hundreds of roofs throughout Germany over a period of one and a half years, and have tested smaller in a kilowatt range and large ground-mounted systems with up to five megawatts,” Matthias Krieg, Head of Maintenance and Service at Eon Energie Deutschland, was quoted by pvEurope. “We want to use the results for the targeted expansion of our maintenance offer. The data also help to identify approaches for further improvements in photovoltaics.”

Result: cables are main deficiency of a PV system

The hundreds of tests E.ON has conducted already all have one clear result: the majority of faults are caused by cables that are not installed correctly or, in some cases, by the wrong choice of cable altogether. In fact, sometimes the chosen cables were not even suitable for outdoor use or for the occurring voltages, which can cause serious damage.

Results will be anonymous but representative

When the complete results of all tests will be published, E.ON will not disclose any information regarding the location and size of the plants, the commissioning, the electricity generated and the results obtained. Instead, the shared results will be a representative average. Nonetheless are they meant to show the proportion of installations in perfect shape and give information regarding yield damages and malfunctions with an impact on safety. Furthermore, it will be possible to to identify whether specific regions, grades or types of modules are especially affected by this.