Field investigation of the effect of spectral response upon photovoltaic energy yields

The operating efficiencies of multi-junction photovoltaic cells are sensitive to changes in the spectral distribution of solar irradiance. To examine how this affects their performance in the field, two sets of triple-junction photovoltaic cells with different spectral responses are being characterised side-by-side outdoors. Initial analyses of the measurements have revealed seasonal differences between the performances of the cells that can be attributed to their spectral responses. This suggests that more long-term data will show how the choice of spectral response can impact the annual performance ratios for multijunction photovoltaic systems.