Recent advances in outdoor performance evaluation of PV systems

Sandia's Photovoltaic Technology Laboratory (PTEL) routinely performs outdoor tests of a variety of one-sun and concentrator PV modules. Their experience is that while outdoor testing has its own set of problems, it can produce results that are more directly applicable to "field" conditions than testing in solar simulators. They have recently improved both the hardware and software at the PTEL to improve their accuracy and to deal with the special set of problems encountered in outdoor testing. Improvements in hardware include a computer-controlled solar tracker that allows them to test solar cell arrays up to 21 m/sup 2/ in size; infrared imaging of modules; and electronic loads that allow them to test components with outputs up to 1,800 watts. Improvements in software include real-time monitoring of data collection; a relational database that has improved the reliability of test setups, operations and analyses; and a standardized reporting process that relates module performance to a number of environmental parameters.<
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