Advances in solar greenhouse systems for cultivation of agricultural products
Résumé
As the world’s population grows, current agricultural activities are putting enormous strain on the climate, including deforestation, excessive water use, and pesticide runoffs. These stresses are expected to increase in the coming future as more food products are needed. One promising method to reduce the adverse impact on the environment is greenhouse-based farming, which can enhance land-use efficiency and water consumption. The major limitation of the greenhouse is the high energy demand in a constrained space. Solar energy has shown a promising approach for integration with agricultural greenhouses in recent years. The developments of greenhouses integrated with various solar energy technologies including photovoltaic (PV), photovoltaic-thermal (PVT), and solar thermal collectors are discussed in this chapter. The results indicated that PV modules installed on greenhouse roofs or walls cause shading and, in some cases, have affected the growth trend of cultivated crops inside. The PVT modules are more efficient at producing both heat and electricity, while higher performance values are reported for greenhouses integrated with solar thermal collectors especially in moderate climate conditions. Additionally, storing thermal energy has shown an improvement in the profitability of solar greenhouses by extending the period of solar heat availability. Also, the most commonly used mathematical models describing the thermal behavior of solar greenhouses as well as their economics are explored and discussed. In the end, various commercial solar greenhouse implemented around the world are introduced.