Performance analysis of radiation and electricity yield in a photovoltaic panel integrated greenhouse using the radiation and thermal models

The agricultural photovoltaic panel integrated greenhouse (PVIG) are attempted to improve the utilization of solar energy for sustainable agriculture. This study proposes a numerical method to predict the radiation distribution and the electricity yield of a PVIG throughout the year using 3D radiation model and thermal model. The radiation model is validated in a PVIG in the southeast of China with 36 rooftop PV panels of straight-line layout and the PV array covering 25% of the greenhouse roof area. According to simulation of conventional greenhouse and PVIG with straight-line (La), crisscross (Lb) and checkerboard (Lc) PV panels' layouts, the performance of different PVIG is evaluated in terms of the non-uniformity of the radiation distribution, the radiation intensity and the electricity yield of PV panels. The non-uniformity of the hourly radiation under the La layout is not much different from the layout Lb and Lc, and the cumulative weekly radiation under the layout of La is increased by 8.3% and 12.7% in the experimental PVIG, respectively. The thermal model of PV panels mounted on the greenhouse roof is developed to accurately predict the PV electricity yield, considering the impact of greenhouses and external environments on PV panels. In contrast to the layouts of La and Lb, the annual electricity yield of PV panels with the layout of Lc raises by 3.2 and 2.2 kWh M-2 respectively. Compared with conventional greenhouse, the distribution and intensity of cumulative weekly radiation are not significantly affected by the optimal PV array covering 25% of the greenhouse roof area. These results indicate that the 3D radiation model and thermal model can be used as an efficient tool to optimize the performance of PVIG.