Analysis of energy production of Spectrolab multijunction solar cells in field conditions

Multijunction solar cells used in concentrating photovoltaic (CPV) systems deliver solar power at low cost in high DNI climates where the solar resource is greatest. Because the cells subdivide the solar spectrum and are used with optical systems of varying spectral response, careful evaluation and optimization of cell performance under real field conditions is important. This paper presents modeled performance of the latest generation Spectrolab cells in systems with PMMA and silicone-on-glass optics, using a simple cell temperature model, TMY3 data, and the SMARTS spectral irradiance model. Results show that the improved efficiency of C4P5 cells compared to the lattice-matched C3P5 cells is more pronounced in systems with PMMA optics.