Determination of the Optimal Orientation of Chinese Solar Greenhouses Using 3D Light Environment Simulations

With the continuous use of resources, solar energy is expected to be the most used sustainable energy. To improve the solar energy efficiency in Chinese Solar Greenhouses (CSG), the effect of CSG orientation on intercepted solar radiation was systematically studied. By using a 3D CSG model and a detailed crop canopy model, the light environment within CSG was optimized. Taking the most widely used Liao-Shen type Chinese solar greenhouse (CSG-LS) as the prototype, the simulation was fully verified. The intercepted solar radiation of the maintenance structures and crops was used as the evaluation index. The results showed that the highest amount of solar radiation intercepted by the maintenance structures occurred in the CSG orientations of 4-6 degrees south to west (S-W) in 36.8 degrees N and 38 degrees N areas, 8-10 degrees S-W in 41.8 degrees N areas, and 2-4 degrees south to east (S-E) in 43.6 degrees N areas. The solar radiation intercepted by the crop canopy displayed the highest value at an orientation of 2-4 degrees S-W in 36.8 degrees N, 38 degrees N, 43.6 degrees N areas, and 4-6 degrees S-W in the 41.8 degrees N area. Furthermore, the proposed model could provide scientific guidance for greenhouse crop modelling.