Author: PPD Team Date: 12/02/2025
Researchers from Guilin University of Electronic Technology, China, developed a numerical model to assess how different overhead heights and tilt angles of photovoltaic (PV) modules influence thermal and electrical performance, as well as energy-saving in buildings.
The model, validated through experiments, fills a gap in the literature by providing a comprehensive study on the impact of these factors across various installation types.
Using the Design Builder software, the model accounted for energy exchanges like conduction, convection, and radiation, and was tested with meteorological data from Guilin, China. The experiment compared an enclosed structure with and without PV modules, considering height and tilt angle.
The experimental setup used plywood and reflective aluminium foil to simulate a 200 W monocrystalline silicon PV panel. The model showed a root mean square error (RMSE) of 0.16–2.35 and a mean absolute percentage error (MAPE) of 0.90%–9.38%, confirming the model’s reliability.
Further simulations varied heights (100 mm, 150 mm, 200 mm) and tilt angles (0° to 45°). In summer, the parallel overhead PV roofs generated 307.2 W/m², with efficiency decreasing as the tilt angle increased. In winter, the optimal power supply gain occurred at a 40° tilt (234.6 W/m²).
Energy-saving efficiency peaked at 18.8% in summer, while winter saw optimal efficiency of 25.6% at a 40° tilt. Throughout the year, a 20° tilt angle provided the best balance, with a power gain of 79.4 kWh/m² and an efficiency of 25.5%.
The team concluded that slight adjustments to the overhead height have minimal impact on the overall energy-saving efficiency (less than 0.2%), while tilt angle plays a more significant role in optimizing power generation. Their findings, titled “Effect of the overhead height and tilt angle on comprehensive performance of photovoltaic roof based on simulation and experimental methods,” were published in Results in Engineering.