COUPLING OF PV-POWERED RO BRACKISH-WATER DESALINATION PLANT WITH SOLAR-STILLS

Desalination of water is essential to supply sufficient good quality w ater to remote areas to satisfy various needs. Saudi Arabia has enormo us amount of deep water and the underground water in many areas of thi s country is so brackish that it requires extensive pre-treatment. In order to utilise inland reserves of brackish water by the local inhabi tants, the Energy Research Institute (ERI) of King Abdulaziz City for Science and Technology (KACST) installed a Photovoltaic (PV) powered w ater desalination Reverse Osmosis (R.O) plant at Riyadh, Saudi Arabia. The reject brine rate from this plant is very high. Due to the inhere nt advantages of solar still assemblies, for instance; simple to const ruct and maintain using locally available material, and high technical feasibility in remote areas, a solar still plant capacity of 5.8 cubi c meter distillate per day is proposed to couple with the existing PV- RO plant in order to utilise most of the reject brine instead of throw ing on the ground. The estimated cost of product water obtained throug h this design is found to be Saudi Riyal 1.9 (US$0.50) per cubic meter . The proposed design of the solar still assemblies can be applied to configure a 100% solar powered desalination system for any location an d quality of brackish water. (C) 1998 Published by Elsevier Science Lt d. All rights reserved.