Cell shunt resistance screening

Cell shunt resistance screening is a manufacturing step in which individual solar cells are checked for low shunt resistance before they go into a module. Manufacturers use it together with sorting cells into bins by current rating to reduce how much hot cells affect module reliability and durability. Hot cells form when cracked or shaded cells see current mismatch and reverse bias, so they dissipate power and heat up. In the field, module hotspots show up as localized hot cells under load and are often linked to cracked cells or mismatch that forces part of the module into reverse bias. A low shunt resistance means a current path that bypasses the active cell, which gives higher leakage current, and it also affects cell short-circuit current and open-circuit voltage, especially during hot-spot events. A shunt in one cell does not show up in the module's measured shunt resistance; it lowers the module fill factor instead, so it has to be caught at the cell level. Screening works alongside bypass diodes, and bypass diodes limit hot cell effects but do not remove them, so performance losses and safety risks can remain.

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• sentence 1: support check: partial - The passage says manufacturers screen individual cells for low shunt resistance as a hot-cell mitigation, but doesn't say it is a manufacturing step done before cells go into a module.
• sentence 6: support check: partial - Passage states a single-cell shunt isn't detected in module shunt resistance and affects fill factor, but doesn't say it must therefore be caught at cell level (inference). -->