SunPower Corp., a solar technology and energy services company, announced on October 21st that its high-efficiency SunPower® E20/327 Solar Panel recently underwent stringent third-party testing for potential induced degradation (PID) by PV Evolution Labs. Upon completion, the panels showed power loss of less than 0.2 percent, performing better than any of the others tested. The average degradation of modules that passed this test is approximately four to five percent.
PID is a phenomenon where leakage of electrical current from the solar cell to the panel frame drives ion migration, which modifies the electrical characteristics of the solar cell and degrades the panel's power output. Temperature, humidity and voltage all accelerate this process.

SunPower earned certificates in all grounding configurations and, when compared against conventional panels that passed, its panels degraded at a rate 20 times lower. Only 50 percent of all panels tested successfully passed the program's criteria. A conventional panel is approximately 240 watts, 15 percent efficient and approximately 1.6 square meters in size.

Testing criteria developed by PV Evolution Labs includes subjecting the solar panels to 600 hours of damp heat conditioning, as defined in international testing standards, and maximum rated voltage stress. After 100 hours of testing, a panel must demonstrate less than five percent power loss and less than 10 percent after 600 hours to pass the test. Of the fifty percent that failed, power loss ranged from 18 percent to 87 percent.

During the testing period, visual inspections, flash testing and high-resolution electroluminescence images are taken to accurately evaluate and monitor the panel's durability. The measured data is then compared to criteria developed to determine if the panel has passed or failed the PID program.

Headquartered in Berkeley, Calif., PV Evolution Labs is an independent testing facility that provides companies developing photovoltaic products and projects with secure, expert testing and performance validation services.

SunPower has received several third-party validations over the past several months that confirm the reliability of its solar panels, including:

• Atlas Material Testing Technology, LLC issued an unprecedented reliability rating for the SunPower E20/327 Solar Panel, showing less than two percent power drop across all degradation tests performed
• Fraunhofer announced that the SunPower E20/327 Solar Panel ranked first in its PV Durability Initiative testing, garnering top scores in all ten categories tested
• In the Photon 2012 Module Yield Test, the SunPower E-Series Solar Panels placed first, second and third in highest performing solar panels out of 151 solar manufacturers participating