The Design of a High Concentrator Photovoltaic Module (HCPV)

High concentration photovoltaics (HCPV) promise a more efficient, higher power output than traditional photovoltaic modules. This is achieved by concentrating sunlight onto a small 1 cm concentrator triple junction (CTJ) InGaP/InGaAs/Ge cell by using precision optics. In order to achieve high performance, careful design decisions must be made in the development of a HCPV module. This paper investigated the design of a HCPV module (Module I), which was based on the Sandia III Baseline Fresnel module. The investigation concentrated on the optical design, thermal dissipation and electrical characterization of a CTJ cell. The best performance achieved was at 336 times operational concentration, which produced 10.3 W per cell, a cell and module efficiency of 38.4 % and 24.2 % respectively. The development of the second module (Module II) employed pre-monitoring criteria that characterized the CTJ cells and system components to eliminated faulty components from the system, observed in Module I. These criteria included visual inspection and one-sun Current-Voltage (I-V) characteristic curves. Optimized units in Module II showed no form of degradation in the I-V characteristics and detected defects. The units under thermal and optical stress showed a progressive degradation with operation in the field.