CFD Analysis of Irradiance and Its Distribution in a Photovoltaic Greenhouse

The integration of photovoltaic (PV) panels in greenhouses enables dual land use, combining crop production with electricity generation. However, PV installations can reduce both the intensity and uniformity of light at the canopy level, poten-tially affecting crop growth. This study employed computational fluid dynamics (CFD) simulations to evaluate the effects of different arrangements of thin PV modules—both opaque and semi-transparent—installed at gutter height in greenhouses. The influence of greenhouse size and roof shape on the intensity and uniformity of visible radiation was also investigated. Results showed that, during winter (21 December), irradiance in a mono-span tunnel greenhouse was 4–6% higher than in a multi-span structure; in summer (21 June), this difference increased to 10–13%. Among the PV layouts tested, the north-south straight-line arrangement provided the most uniform light distribution, outperforming check-erboard and east-west configurations. The east-west straight-line layout was the least effective. Roof shape (arched vs. pitched) had minimal impact on radiation distribution. Semi-transparent PV modules consistently resulted in higher irradi-ance and more uniform light distribution than opaque ones. These findings can inform optimal PV deployment strategies in greenhouses to enhance both energy yield and crop productivity.