The PID test assesses how well modules can withstand Potential Induced Degradation (PID). For a module to pass this test its power degradation must be less than 5 percent.
“Despite the highly rigid standards, Canadian Solar modules have been confirmed once again to be PID resistant” said Dr Shawn Qu, the Chairman and CEO of Canadian Solar. “In 2011 and 2012, Canadian Solar modules had passed PID tests done by PI Berlin in Germany and PVLB in USA. This latest test further validates the premium quality of Canadian Solar's modules. We will continue to leverage our state-of-the-art PV testing lab as we work to safeguard the high-quality our solar modules have become known for worldwide over the past 12 years.”
The major root cause of PID is the combination of high level humidity and heat in the environment in which the system is installed. For example a solar power system with P-type (C-Si) modules installed in a hot and humid area without negative grounding can induce a negative bias to build up over time inside the module between its internal circuit and the frame. This in turn gives rise to the PID phenomenon. PID high risk areas include desert areas, tropical regions and locations close to water.
There are several ways in which PID can be reduced including special solar cell and module technology which enhances PID resistance, a well designed system configuration with proper installation and negative pole grounding. Of these, the most effective solution according to PV system experts is negative pole grounding, something which will create very high resistance to PID effects.
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