Solar Radiation Allocation and Spatial Distribution in Chinese Solar Greenhouses: Model Development and Application

Abstract

Solar radiation is the sole energy source for Chinese solar greenhouse agriculture. A favorable light environment is the foundation of a desirable crop growth environment, and it is key in solar greenhouse design. In this study, a mathematical model is established to quantitatively evaluate the solar greenhouse light environment. The model was developed considering the greenhouse shape parameters, materials’ optical properties, and interior solar radiation evolution, including the beam radiation, diffuse radiation, and multi-reflection. The model was validated under different weather conditions, and the results reveal a mean percentage error of 1.67 and 10.30% for clear sunny weather and cloudy weather, respectively, and a determination coefficient of 0.9756. By using this model, the solar radiation allocation in a solar greenhouse was calculated to determine the solar radiation availability for the heat-storage north wall and the entire greenhouse, and the dynamical spatial distribution of the solar radiation was obtained to describe the light environment quality. These allow the optimization of the greenhouse lighting regulation and planting pattern. Moreover, several optimizing measures are derived according to the model for improving the low-light environment near the north wall and maximizing the north wall’s heat storage/release capacity in a solar greenhouse.

Development of a solar radiation sensor system with pyranometer

“…For many years, many stations around the world have measured solar radiation [6]- [8]. The primary goal of these measurements was weather forecasting, agriculture, the prediction of travel plans, and the project of heating [9]- [11].…”

Determination of the Optimal Orientation of Chinese Solar Greenhouses Using 3D Light Environment Simulations

“…As shown in Figure 1, the CSG type is widely used, especially in the north of China. Compared with other greenhouse types, the CSG type requires unique maintenance structures such as the back wall, roof, and quilt to guarantee the winter production of vegetables without any additional heating [9,10]. Previous studies on light optimization of CSG have mainly focused on greenhouse structures [11][12][13] and optical properties of plastic films [14,15], while the orientation of the CSGs has not been considered.…”

A Time-Dependent Model for Predicting Thermal Environment of Mono-Slope Solar Greenhouses in Cold Regions

“…Most of these models are used to predict the diurnal variation of temperature [12,13,15] and humidity [14,16] inside the greenhouses. Zhang et al [17] and Huang et al [18] developed mathematical models to simulate the light environment (solar radiation) inside of CSGs. A few studies developed models for specific purposes, such as investigating the potential of renewable energy (solar and wind) to power the solar greenhouse [19], heat-pipe heating system [20], optimizing design parameters [21,22], etc.…”