Cracking is due to excessive thermal or mechanical stress applied to the module, which may occur during manufacturing, transportation, handling, and even after deployment. In fact, for most tests, cracks tend to start out too small to be detected, and grow over time to reduce module performance, which makes the situation more complicated.
The component reliability expert PVEvolutionLabs (PVEL) passed rigorous stress tests and put together more than 40 components representing most commercial technologies to better understand the possibility of cracks and the possibility of affecting on-site performance.
Some of their observations were published in a new white paper. The conclusion of this article is that each module behaves differently, and testing a specific bill of materials (BOM) is the only way to determine its sensitivity. However, PVEL's testing also revealed some interesting trends in new technologies and cracking risks.
The white paper found that some of the latest technology trends can help reduce the risks associated with cracking-monocrystalline cells currently accounting for more than 80% of the market are not easily affected. Possibility of activity area.
After passing the mechanical stress test of PVEL, the interdigital back contact module, glass and thin film technology have almost no cracks. The half-cut groove technique also shows that the risk of cracking can be reduced by more evenly distributing the pressure on a smaller surface, provided that the formation of micro-cracks is avoided during the groove cutting process.
Another trend revealed in the test is that larger module surface area tends to equal more cracks-this is a highly relevant finding, considering the switch to a larger format to continue to play in module manufacturing.
PVEL warns that whether it is a wafer or a module, a larger surface area means more deflection under high loads and a greater risk of cracking. The high-density interconnection technology reduces the gap between the cells and also increases the mechanical stress on a single cell. The white paper provides an example where two modules of 120 and 144 units, which otherwise have the same BOM, were tested, and the 144 unit version showed significantly more cracking.
They also pointed out that storms, temperature changes, and other weather conditions may cause site cracking. The increase in the frequency of extreme weather events in many areas further increases the risk of cracking, while also causing other damage to the site modules.
PVEL experts concluded: "Crack sensitivity is subtle. Some new technologies are not easy to crack, but some old technologies may perform better than new technologies. Crack sensitivity ultimately depends on the specific applications used in the production of photovoltaic modules. Components and manufacturing technology.” The laboratory plans to continue testing, and next year there will be a list of nearly 100 new materials.