Early performance for the roof-mounted, 20-kW thin film CdTe PV array at Jasper Ridge

Here we report early performance for the grid-connected, 20-kW CdTe PV array installed on the roof of the Leslie Shao-ming Sun Field Station at the Jasper Ridge Biological Preserve. The array was installed in May 2002. Data are reported for 20-mos beginning April 2003. The array originally consisted of 275, BP Solar 80 W thin-film CdTe modules arranged in 11-module strings. The monitoring system logged data from 9 sensors on 1-min intervals. Monitoring showed problems with maximum power tracking associated with module degradation, elevated module temperatures, and the finite voltage window of the 208 VAC-Sp inverter. The problems were addressed in May 2004 by rewiring the array and reprogramming the inverter, resulting in a 20% increase in energy production.