A photovoltaic testing system devised at Arizona State University measures system voltage as a function of light intensity in outdoor settings for real-time performance measurement and diagnostics.

When solar cells are developed, the devices are current-voltage tested in the laboratory before being deployed in panels and systems outdoors. Once installed outdoors, they are not usually tested again unless the system System voltage is measured as a function of light intensity in outdoor settings. Source: Arizona State UniversitySystem voltage is measured as a function of light intensity in outdoor settings. Source: Arizona State Universityexperiences performance problems. The new Suns-Voc (open circuit voltage) test system measures voltage as a function of light intensity in an outdoor setting, enabling real-time measurements of performance and detailed diagnostics.

While available solar modules are rated to last 25 years at 80% efficiency, the goal is to expand that time frame to 50 years or longer. According to the researchers, data generated by the new monitoring and test method will enable photovoltaics engineers and utility operators to fine-tune designs in pursuit of longer, more efficient service lives. The new approach automatically measures outdoor solar efficiency during sunrise and sunset without the need to disconnect from the power delivery mechanism.

Measurements normalized using both backsheet temperature sensors and on-site weather stations were demonstrated to fall within 1% of the laboratory measurements. Simulations confirmed that shading portions of a system has minimal effect on measurements, allowing the technique to be used in all weather conditions.

Field tests have been completed at the university campus and the researchers now plan to demonstrate its merits for a California utility preparing to install 1 MW of silicon photovoltaics capacity.

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