10 GW time bomb
Serious problems with prematurely aging back coatings were detected in a total of 10 GW of solar modules. It is stated that the problem causes leakage currents and reduces the efficiency of the systems and requires repair. To solve this problem, experts state that insulation measurement should be done with inverters. The identified problem specifically affects “AAA” backsheet films made of three-layer polyamide used between 2010 and 2013. However, it now appears that newer modules and different foil types are experiencing similar problems.
The problem is quite big
The problem identified in Germany affects approximately 15 percent of the country’s solar energy capacity. It is reported that the replacement cost of the affected systems may reach 2 billion Euros. Currently, not all of the solar panels or modules that have turned into ticking time bombs have been detected. However, it is stated that these modules pose a risk of electric shock in rainy weather because they create leakage current. On the other hand, if the back foil on the modules is torn, we can say that it is only a matter of time before the stability of the module will completely deteriorate.
A fundamental underlying problem is that the modules affected by the problem are just starting to turn profitable. As it is known, solar panels generally cover their costs within 10 years and turn a profit. In the newest modules, the payback period has become even shorter.
The Anomalous project’s findings will form the basis of an equipment safety standard expected to be published later this month. This standard (German VDE) will help identify, classify and evaluate module backsheet defects and monitor changes in these defects.
However, this standard is aimed at experts and professionals. Because it is impossible to detect the mentioned problems for individual users. It is stated that individual users will be able to detect visible defects such as chalking, discoloration, corrosion on electrical connectors, cracks, delamination or burn marks. In this case, the best way is to consult the manufacturer or installer. In large-scale structures such as solar energy facilities, it is necessary to perform tests in laboratory environments to detect damage.