Integration between concentrated solar power plant and desalination

Fresh water and electricity production in desert areas via the use of solar radiation represent examples of sustainability. The concentration of solar power by means of parabolic trough (PT-CSP) technology has a great potential not yet exploited in the realm of renewable energy production. A new technology for the solar energy section is being proposed by the authors which uses air as a working fluid. The use of air allows the cycle to be coupled with an inter-cooled compression section and a re-heated expansion section which is called Discrete Ericsson Cycle, (DEC-based plant). The paper presents an integration of such a CSP-DEC plant with desalination: where freshwater is produced according to a Low Temperature Multi Effect Distillation (LT-MED) technology. The LT-MED plant operates on the heat from the air coolers in the inter-stage cooling of the DEC-based plant. This heat is normally expelled to atmosphere. In fact, the heated air has the same temperature ranges required for the operation of the LT-MED desalination technology. This provides an efficient integration of energy for desert applications. The most important feature of this new solar energy plant is that the thermal needs of desalination in DEC-based plants do not interfere with the electricity production of the plant as is the case for current conventional PT-CSP plants which use diathermic oils as Heat Transfer Fluid (HTF). When the performance of the CSP DEC-based plants, integrated with the LT-MED technology, are compared to conventional CSP plants, they show an increased efficiency in terms of fresh water production per unit of energy produced. Thus, fresh water production can be considered as a valuable addition to the plant.