Energy saving and economic competitiveness of solar desiccant cooling technology – A case study of the Moroccan Kingdom

Abstract

As many countries in the world, Morocco is vulnerable to climate change having direct impacts on its main economic sectors highly dependent on natural resources. This is exemplified, among other things, by long periods of drought, increase of average temperatures and successive heat waves. These circumstances have increased the demand for cooling energy, particularly in tertiary building where centralized air conditioning systems still predominant. Currently, the installed power capacity seems to be insufficient to respond effectively to this increasing demand. In this context, sustainable alternatives to traditional cooling systems such as solar air conditioning systems can be a suitable option for energy efficiency and security. Solar desiccant cooling systems present a great opportunity since they do not use any ozone-depleting coolants. This study discusses the techno-economic feasibility of solar desiccant systems in tertiary building, in particular a conference room, compared to a conventional air handling unit. Besides the use of air solar collectors to heat up the regeneration air, the particularity of the studied system is the use of exhaust air leaving the desiccant wheel and purge zone to preheat regeneration air. Accordingly, simulations were performed in three climatic regions with different enthalpy loads. The main result of this work is that solar desiccant cooling systems can be an attractive investment if appropriate economic conditions are met with a substantial governmental support, since a significant energy-saving of about 77% can be achieved compared to conventional systems.