Comparison of PV module performance before and after 11-years of field exposure

In 1990 the Schatz Energy Research Center (SERC) installed a PV array comprised of 192 ARCO M-75 modules. Prior to installation, Zoellick carefully measured module performance and reported average peak power at normal operating cell temperature (NOCT) to be 39.88 W, which was 14.1% lower than the 46.4 W nameplate rating. For the past 11 years the array has been exposed to and employed in a cool, marine environment. Of the original 192 modules, 191 were tested in order to re-evaluate their performance. This paper describes the equipment, conditions, and procedure used in retesting the modules, and reports module performance results. Notable results are that average module short circuit current and maximum power production at NOCT have decreased by 6.38% and 4.39%, respectively.