Performance of a 5 kWe solar-only organic Rankine unit coupled to a reverse osmosis plant

Organic Rankine Cycle (ORC) systems are one of the most promising energy conversion technologies available for remote areas and low temperature energy sources. An ORC system works like a conventional Rankine cycle but it uses an organic compound as working fluid, instead of water. A small ORC unit coupled with a solar thermal energy system could be used to convert solar thermal energy into electricity in remote areas, offering an alternative to Photovoltaic (PV) systems to provide the energy required by desalination applications like reverse osmosis (RO). In this work an analysis of the performance of a specific solar desalination ORC system at part load operation is presented, in order to understand its behavior from a thermodynamic perspective and be able to predict the total water production with changing operation conditions. The results showed that water production is around 1.2 m(3)/h, and it is stable during day and night thanks to the thermal storage and only under bad irradiance circumstances the production would stop. (C) 2013 M. Ibarra. Published by Elsevier Ltd.