Solar cooling technologies: State of art and perspectives

The energy demand for cooling and air conditioning systems is increasing worldwide, especially in regions with high solar radiation intensity. One of the reasons for this is the increase of comfort demands worldwide. The most cooling and air conditioning systems are the conventional electrically driven one type such as compression refrigeration machines and air conditioning systems. Through the huge electricity consumption for cooling and air conditioning, the environmental problems get bigger and bigger, because of carbon dioxide (CO2) and other pollutant emissions. One of the possibilities to reduce the primary energy consumption is through the use of solar energy for driving the thermal driven absorption or adsorption refrigeration systems, or desiccant cooling. Another possibility is using solar energy to produce electrical energy and this can be used to drive the conventional refrigeration systems. Many research and developmental efforts in the last years have been done to enforce the spreading of solar-driven cooling systems. This paper will illustrate the state of the art about the energy consumption for cooling and air conditioning systems, available solar-driven cooling systems and the potential of the utilization of such systems in comparison to the conventional ones. Moreover, this paper highlights some different methods of optimization, which used to maximize the performance and minimize the cost.