A simplified methodology for estimating solar spectral influence on photovoltaic energy yield using average photon energy

Abstract

Nowadays, investors, customers, and even suppliers focus on the bankability of photovoltaic (PV) technologies. However, few studies have investigated the annual net effect of solar spectrum. In this study, we estimate the net effect of the solar spectrum on the annual energy yield of c-Si and a-Si modules by two parameters. One parameter is a direct calculation from spectral factor (SF). The other parameter uses average photon energy (APE) and a regression line or curve. The estimations by the two parameters are quite consistent, whereas there is 1.2% difference between the estimations at most. Therefore, APE would be a useful index to quantify the effect of the solar spectrum. In thi study, we estimate the net effect of solar spectrum on the annual energy yield of c-Si and a-Si modules using two parameters. One parameter is directly calculated from spectral factor (SF), and the other parameter is calculated from average photon energy (APE) and a regression line or curve. APE may be a useful index to quantify the effect of solar spectrum simply and easily, because the estimations by the two parameters are quite consistent with each other.