Exergy Analysis of the Solar Blind System integrated with a Commercial Solar Greenhouse

Abstract

The commercial greenhouse known as the most energy demanding cultivation methods and the energy conservation solution such as solar blind system is essential to be considered for the commercial greenhouses due to the sustainability. The solar blind system is consisted a series of thermal photovoltaic collectors which can rotate around the horizontal axis in order to make shading effect on the greenhouse and act as the solar curtain. In the conventional greenhouse, the solar curtain is utilized regularly to reduce the greenhouse indoor temperature by blocking the incoming solar radiation and it also prevent the sky night heat losses. Then by considering the solar blind system, not only the greenhouse cooling load can be decreased considerably, but also it can cover a part of electrical and heating demand of the greenhouse. Therefore, more energy can be conserved through the greenhouse by considering the solar blind system that leads to higher system exergy efficiency.

In order to conduct the exergy analysis a solar blind integrated greenhouse is modeled which is validated using measured data a case study greenhouse in Shiraz, a southern city in Iran. The results show that by integrating the solar blind system in the commercial greenhouse the annual exergy efficiency can be increased from 0.2% to 4%. However, the maximum possible hourly exergy efficiency can be increased from 36% to 69%.