Experimental and numerical investigation of the influence of terrain slope on the of-axis trackers

Certain advantages of using mountainous terrain for the installation of solar plants are well known, such as lower temperature, higher solar irradiance present at high altitudes, and economic aspects related to the lower cost of land. This paper highlights another one: the higher annual solar irradiation incident of single-axis N-S trackers installed on sloping terrain, as compared to horizontal ones. After a theoretical study in which the relevant formulas are derived, numerical simulations are presented. Then we showcase the results of a year-long experiment in which a N-S aligned single-axis tracker prototype was used, at the location of our Department (Gijon, Spain). The experimental results confirm the trends in the formulas and simulations. Finally, theoretical values for the energy gain for different slopes, at locations over the northern hemisphere between latitudes of 6 degrees and 60 degrees are provided. These gains can reach values up to 13.5%.

Automated summary

This paper explores an advantage of using mountainous terrain for solar plant installation: higher annual solar irradiation incident of single-axis N-S trackers installed on sloping terrain compared to horizontal ones. Theoretical study, numerical simulations, and experimental results confirm this advantage. Theoretical values for energy gain at different slopes between latitudes of 6 degrees and 60 degrees in the northern hemisphere are provided, with gains reaching up to 13.5%.