Weekend Read: A 10 GW time bomb
It is estimated that 10 GW of solar modules in Germany suffer from prematurely aging backsheets, with sites of all sizes affected.
pv magazine Germany’s Cornelia Lichner looks at how to detect and repair such defects.
SEPTEMBER 9, 2023 CORNELIA LICHNER
If the back foil tears, it is only a matter of time before the stability of a module fails completely.
From pv magazine 07-08/23
Holger Schultheiß suspected what the installer inspecting his 11-year-old roof-mounted solar system last fall would find. Neighbors had experienced the same problems with inverter failure and strings staying offline.
The rear of the modules displayed checkerboard cracks, some visible from the front. Moisture in the panels caused leakage currents to flow between positive terminals and the ground. The inverter, which measures insulation, does not activate if insulation is too low. Around half the modules in Schultheiß’ 200 kW system were affected – in a year when installers had no time for repairs.
It has long been known some “AAA” backsheet films – made of triple-layer polyamide and widely deployed from 2010 to 2013 – can become brittle and tear. “By now, you would have to see the signs in all modules affected by this, whether they are installed in ground-mounted systems or on roofs,” says Bernhard Weinreich, managing director of HaWe Engineering. Now, younger modules and other foil types are exhibiting similar behavior.
Big problem
https://www.pv-magazine.com/2023/09/09/weekend-read-a-10-gw-time-bomb/
