Optimum design of a greenhouse for efficient use of solar radiation using a multi-objective genetic algorithm

The usage of solar energy in greenhouse cultivation is a proven solution for massively surging energy consumption problem in today society. Moreover, efficient use of solar energy in the greenhouse industry leads to extending the greenhouse cultivation calendar beyond the traditional greenhouse farming. Therefore, for improving the utilization of solar radiation in the greenhouse, this study systematically investigated the effects of physical dimensions and orientation on captured solar radiation in an even-span greenhouse for northern areas of Iran. An anisotropic solar radiation model based on the meteorological data, optical properties, and solar radiation distribution in the greenhouse is developed to calculate the transmitted solar energy available inside the greenhouse, which taking solar radiation loss from all the greenhouse sections into consideration. The best design parameters for two considered cultivated land areas is selected in a multi-objective optimization with the goal of maximizing the solar radiation in the greenhouse in winter and minimizing the solar radiation in summer as well as minimizing the cover area of the greenhouse. The final set of design parameters for each greenhouse is selected with LINMAP decision-making method. The results show that regardless of the greenhouse cultivated land area, the optimal roof inclination angle, the total height, and orientation of the greenhouse are 14?degrees, 3.6 m, and E-W orientation, respectively, with regard to the greenhouse length; based on the floor area size, the length to width ratio should be maximized for the best use of solar radiation in the greenhouse in the location of this study (Rasht, Iran).