MEASUREMENT OF CPV MODULE ENERGY YIELD: A COMPARISON OF MAXIMUM POWER POINT TRACKING AND CURRENT-VOLTAGE CHARACTERISATIONS

The procedure for measuring concentrator photovoltaic (CPV) module output power is detailed in the draft IEC standard 63670-3. Though the procedure does not require a module to be held at a particular voltage bias condition between measurements, it is appreciated that this can affect the operating temperature of cells within. An experimental set-up has been assembled in Nicosia, Cyprus, capable of outdoor current-voltage measurements as well as maximum power-point (mpp) tracking. The set-up has been used to test three CPV modules under normal operating conditions outdoors over several weeks. The current-voltage (I-V) characteristics of the modules were accumulated whilst being held under both mpp and at open-circuit voltage (Voc) bias between measurements. Integrated temperature sensors provided an indication of the actual junction temperature of the cells under each bias condition. It was found that the choice of bias condition could alter the cell operating temperatures by 3-4 °C in the case of high-efficiency modules, equating to an average relative power loss of ~2% when operating in the hotter condition. It is concluded that the assertions contained in the draft standard are valid for power measurement if temperature measurements are performed in very close proximity to the cell.

NORTON Matthew;  KENNY Robert;  GOTTSCHALG Ralph;  GEORGHIOU George; 

2013-05-30

WIP

JRC69882

3-936338-28-0,