Energy Yield Modeling of Single-Axis Tracking PV Systems on Irregular Terrain

Single-axis tracking photovoltaic (PV) systems are being increasingly deployed on irregular terrain, which is pushing the industry towards the development of advanced trackers and novel tracking algorithms. This paper examines the variation of the most relevant losses and performance of single-axis tracking PV systems when considering diverse tracking algorithms and terrain models of different resolution, up to 2-meter digital elevation models. DNV's SolarFarmer is used to model a fictitious single axis tracking PV plant in uneven terrain with varying and non-uniform slopes. The results demonstrated the importance and value of detailed 3-D modeling to quantify tracker terrain losses in PV systems, which reached up to 3.8% in the studied case study. The findings illustrated how terrain complexity hinders the performance of traditional backtracking algorithms and highlighted how custom rotation schedules can account for local terrain and benefit from the topography to achieve higher energy yield, e.g., 0.15% in the case study. Nevertheless, this work reveals that there is not a universal solution for uneven terrain sites and showcases the importance of terrain data integration in solar energy assessments.