Performance assessment of the integration of semitransparent solar cells with different geometry of greenhouses under different climate regions

Abstract

A lack of resources and suitable farming lands, climate change, and a rapidly growing population are some of the main concerns of the societies that pose security challenges to the governments. Creating controlled environments for cultivation, growing plants, and farming, such as greenhouses, may assist in overcoming these challenges. Greenhouses can significantly increase land use efficiency in agriculture by increasing crop yield and harvesting throughout the year, which has long been proven effective. The history of greenhouses for farming dates back to Roman times, and there are different barriers to their applications. An example is the provision of energy to control the cultivation conditions of plants in greenhouses, particularly for heating and cooling hot and cold climate areas. On the other hand, based on the global energy trend, decentralized energy production based on solar energy is highly regarded. In the same way, that households can harvest solar energy, greenhouses can also benefit from solar energy. However, because greenhouses need sunlight to cultivate plants, reducing sunlight using common photovoltaic panels is not logical. By incorporating semitransparent solar cells into these greenhouses, the issue of reduced sunlight could be addressed, and further efficiency gains could be achieved by reducing energy demand in these greenhouses. This research investigates the energy supply system's integration with greenhouses consumption. First, we assess different conventional types of greenhouses in terms of energy demand. Then, we investigate the energy demand with organic photovoltaic (OPV) integration for each type. Finally, the best design of the greenhouse for OPV integration is recommended. Results show that flat arch geometry is the best choice for dry and cold climates, while sawtooth geometry showed better improvements in tropical climates. In both temperate/mesothermal and continental/microthermal climates, A-frame geometry showed superiority in energy saving. Simulations revealed an annual electricity generation for a unit floor area of the greenhouses to be 173.7 kWh/m² to 247.9 MWh/m² for the optimum structural geometries that decrease the energy consumption of greenhouses. Additionally, the results show that the installation of the OPV can decrease energy consumption from 15 to 58% based on the greenhouse's location and structural geometry.

Keywords: Greenhouse; OPV; Organic photovoltaic panel; Semitransparent solar cells.