Spatial estimation of the optimum PV tilt angles in China by incorporating ground with satellite data

Abstract

Tilt angle is a key parameter that affects solar photovoltaic (PV) power generation. Traditional empirical model based on latitude may fail to estimate the optimum tilt angle in regions with large climatic differences. In this study, we propose a framework that incorporates ground with satellite data to determine the optimum tilt angle at any location. We collect global solar radiation measurements of 133 stations in China and estimate the diffuse fraction through Boland–Ridley–Lauret model. Hourly PV power generation is modelled by considering photoelectric conversion process and PV system losses. The results show that the optimum tilt angles are highly correlated with latitude and diffuse fraction with an R of 0.86 and 0.80, respectively. Empirical models reconciled by diffuse fraction allow for spatial estimates of the optimum tilt angle from satellite data to reflect the climatic influence. Furthermore, we explore the benefit from periodically adjusting the tilt angle in China. PV panels fixed at the optimum tilt angle increase the annual power yield by 13.7% compared with horizontally fixed panels. Seasonal adjustment largely increases power yield in winter; additional yield gain of monthly adjustment is very limited; while tracking systems provide the option of achieving double or even triple gains.