Efficiency Evaluation of a PVT Solar Water Heating System Applied to the Greenhouse Climate

The purpose of this paper is to use only solar energy for the greenhouses heating. A hybrid Photovoltaic-thermal collector with the capability to produce thermal and electrical energy simultaneously has attracted the attention of farmers in Tunisia, particularly in terms of improving energy saving and reducing the cost of heating greenhouses agricultural in the cold period of the year. Tunisia has a sunny climate; the use of solar energy to heat greenhouses can be a solution to reduce the heating cost to zero. A numerical and experimental study was previously made on the solar water heating system (SWHS) applied to a small greenhouse [1]. It was noted that the solar supply is very insufficient for heating needs [2]–[3]. However, photovoltaic-thermal collector heating was added to the tested system. The novelty of this article lies in a long-term approach to the operation of a hybrid photovoltaic-thermal collector under Tunisia climatic conditions. The heating system is based on capillary heat exchangers, photovoltaic panel and hybrid photovoltaic-thermal collector [4-5-6]. This study analyses tow model installations with PV, PVT and other devices built in the transient systems simulation program. These systems are applied in agricultural applications in Tunisia. In this work, a numerical study was conducted using Transys 16 to achieve the typical dimensions of the systems and to improve their thermal efficiency.