Towards the maximization of energy performance of an energy-saving Chinese solar greenhouse: A systematic analysis of common greenhouse shapes

Abstract

Determining the optimal shape for greenhouses that is suitable for cold northern regions is essential for non-seasonal fruit production. In the present study, a structural model was developed for energy-saving Chinese solar greenhouses (ECSG), which combines a greenhouse energy balance model with a detailed shape analysis. All possible greenhouse shape interpolations within four common front shape extrema were systematically analysed to determine an optimal ECSG shape with a maximal energy performance for use during winter. The analysis revealed a direct relationship between the interception of solar radiation in the greenhouse and the height of the ridge. Our results indicated that the flatter the curve of the front cover, the more radiation is intercepted by the ground and north wall of the greenhouse. As a result, compared to the commonly used greenhouse type, two types of optimal ECSG shapes were identified, each attaining an increase of 2°C in the minimum night temperature. The general model framework developed in this study allows the investigation of the effects of different variations in the many small detailed interpolation shapes of ECSGs for any arbitrary latitude which can be used directly to provide guidance for the construction of a new generation of energy-efficient solar greenhouses. Also, with the interpolation method proposed in this paper, large-scale shape statistical analysis now can be performed to help qualified decision-making during the process of greenhouse construction.