Modeling and Performance Evaluation of Hybrid Solar Cooling Systems Driven by Photovoltaic and Solar Thermal Collectors—Case Study: Greenhouses of Andalusia

Abstract

Sustainable greenhouses have gained relevance in recent years due to their potential to reduce the carbon footprint of the agricultural sector by being integrated with renewable systems, contributing to the decarbonization of energy. Although solar technologies tend to be more accessible to cover the system’s energy demands, greenhouses are subject to installation area restrictions, limiting their energy potential. This research evaluates the energy advantages of hybridizing solar thermal collector fields with photovoltaic module fields to cover a greenhouse’s cooling and heating demands. For this purpose, the solar thermal field and the photovoltaic solar system were simulated with TRNSYS and MATLAB, respectively, while a method was developed to simulate the performance of a single-effect absorption chiller that was validated using the temperature measurements of a chiller in operation. The results show that the general method maintains differences between measurements and simulation smaller than 5% with set temperatures between 5.5 and 12 degrees Celsius. The hybrid system, with an air-to-water chiller as the main machine and absorption chiller, reached a solar fraction of 0.85 and a fractional energy saving of 83%. This represents a 27% reduction in area concerning an individual solar thermal system. This research highlights that the solar hybrid configuration reduces fossil energy consumption by improving the global efficiency of energy conversion, thereby reducing the area of the solar field.

Keywords

• hybrid solar cooling system
• solar heating and cooling systems
• solar photovoltaic
• solar thermal
• absorption chillers
• sustainable greenhouse