Desalination is a drought-resistant alternative for freshwater generation, especially for arid southwest with history of recurring droughts. With growing population and changing climate, water demands in the region are increasing, thus desalination becomes an effective option to supplement limiting freshwater resources. A major barrier to desalination is its high energy consumption and associated cost. Using renewables as an energy source for desalination has the potential to make it less costly and more sustainable. Las Vegas Valley is underlain by a shallow brackish groundwater aquifer with total dissolved solids levels varying from 1,500-3,000 mg/L. The objective of this study was to determine the potential of using solar photovoltaic (PV) for pumping and desalination of a brackish groundwater for a selected well field in Las Vegas Valley. The generated freshwater was used for landscape irrigation, for washing PV panels, as well as a source of drinking water. Brackish water pumping and desalination system using reverse osmosis was designed using industry accepted criteria, and the corresponding energy consumption was determined. System Advisor Model was used for performance and economic assessment of solar PV. Energy consumption was shown to be largest for reverse osmosis (RO) process. RO concentrate management was addressed using evaporation ponds. Sufficient landholdings were available for deployment of solar PV. Solar PV was found to be economically viable with positive net present value. For future, the methodology used in this study can be applied to other regions for sustainable inland desalination of brackish groundwater.
Sajjad Ahmad– Professor, University of Nevada Las Vegas, Las Vegas, Nevada
University of Nevada Las Vegas
Las Vegas, Nevada
Dr. Sajjad Ahmad is a Professor in the Department of Civil and Environmental Engineering and Constructions at University of Nevada, Las Vegas. His current research interests are in evaluating the impact of climate variability and change on hydrologic cycle, water-energy nexus, probalistic forecasting and downscaling, and integrated water resources management.