1. The Use of Potential Renewable Energy Resources for Developing Sustainable Water Supplies Tamim Younos Virginia Water Resources Research Center and Department of Geography, Virginia Tech Safe and adequate water supplies are needed to protect public health and to sustain economic productivity. The Engineer of 2020, a National Academy of Engineering publication quotes: “The question of water is at the heart of a 600-page world water development report issued by the United Nations in 2003. It’s projected that within the next 20 years virtually every nation in the world will face some type of water supply problem.” In coming decades, significant increased water demand is expected in Northern Virginia, Hampton Roads and population and industrial centers in Virginia. To meet future global water demand, in addition to developing conventional surface and groundwater sources that are quickly diminishing, it will become necessary to develop alternative water sources. Potential alternative water sources include urban storm water runoff, municipal wastewater treatment plant discharges, saline and other waters that are impure for human consumption and economic uses. Currently, advanced and highly effective water purification systems using technologies such as membranes and thermal (distillation) processes are being developed for this purpose. However, these advanced water purification technologies are energy intensive and feasibility of implementing these technologies are directly affected by energy consumption. There is a significant need to integrate renewable energy resources into water production systems. Potential renewable energy resources include solar energy (e.g. photovoltaic and solar energy concentrators/collectors), wind energy, geothermal energy, and ocean energy (tidal power, wave energy, and thermal energy). This poster presentation provides an overview of the potential use of renewable energy resources for developing sustainable water supplies that implement advanced water purification technologies. The presentation addresses the potential and limitations of these alternative energy resources for production of sustainable water supplies in Virginia and the need for developing interdisciplinary research, institutional framework, and policy making to meet future global water demand. Acknowledgments: Kimberly Tulou assisted with research, Jane Walker with editing, and Kelly Davis with developing the poster. Younos, T (Ed.). 2005. Desalination – A Primer. Journal of Contemporary Water Research & Education. Universities Council on Water Resources, Carbondale, Ill. 52 pp. To order e-mail: ucowr@siu.edu. Younos, T. 2004. The feasibility of using desalination to supplement drinking water supplies in Eastern Virginia. VWRRC Special Report SR25-2004. Virginia Water Resources Research Center, Virginia Tech, Blacksburg, VA. 114 pp. Available Online: www.vwrrc.vt.edu/publications/recent.htm 1. 1. Develop an atlas of potential renewable natural resources in Virginia with regard to their availability and potential in a Geographic Information System (GIS) environment 2. 2. Form an interdisciplinary research team of experts in energy, water purification technologies, water resource economics, and geospatial analysis to develop a template for overall research needs and costs 3. 3.Create a statewide task force that includes representatives from regulatory agencies, utilities (water and power), academia, and citizens that will develop the framework for institutional infrastructure and implantation strategies for using renewable energy for water production. Membrane Technologies Membrane water purification processed use either pressure-driven or electrical-driven technologies or a combination of these technologies. Reverse Osmosis (RO), a pressure-driven process, is the most common technology in the United States. Energy is needed to operate the process. Thermal Technologies Thermal technologies use evaporation and distillation processes to purify water. The process is highly energy intensive and uncommon in the United States. Advanced technologies such as Mechanical Vapor Compression (MVC) integrate thermal and mechanical energy. STATEMENT OF THE PROBLEM ABSTRACT RECOMMENDATIONS REFERENCES Photovoltaic arrays convert solar energy into electricity through the transfer of electrons. The arrays are made of silicon chips because silicon effectively and efficiently transfers electrons. When sun rays shine on the silicon chips, the electrons jump to another orbit. This movement creates a voltage that can be used to power pumps for water purification. APPLICATION POTENTIAL IN VIRGINIA Energy Conservation Increase Output of Traditional Sources (coal, oil, nuclear) Using Renewable Energy Sources (solar, wind, geothermal, ocean) APPROACHES TO MEET ENERGY DEMAND Water Purification Technology Type of Energy Work* Consumed (kwh/m 3 ) Reverse Osmosis (RO) Mechanical Energy4.2 – 10.0 With Cogeneration & Steam 2.3 – 5.8 Electrodialysis (ED) Electric Energy1.7 Multistage-Flash Evaporation (MSF) Thermal Energy18.8 + Mechanical Energy 23.2 With Cogeneration4.7 Low Temperature Multi Effect Evaporation (LT- MEE) Thermal & Mechanical Energy 5.0 With Cogeneration2.1 – 4.6 Multi Effect Evaporation- Thermal Vapor Compression (MEE-TVC) Thermal and mechanical Energy 9.0 – 17.0 Mechanical Vapor Compression (MVC) Mechanical Energy6.0 – 18.5 Hybrid RO/ME Thermal & Mechanical Energy 1.35-1.6 WATER PURIFICATION TECHNOLOGIES AND ENERGY CONSUMPTION INTEGRATING RENEWABLE ENERGY RESOURCES TO PRODUCE SUSTAINABLE WATER SUPPLIES Advanced Water Purification Technologies Potential Renewable Energy Resources Alternative Water Sources Solar Wind Geothermal Ocean Wastewater Runoff Saline Water Other Sustainable Water Supplies GLOBAL EXAMPLES USING RENEWABLE ENERGY RESOURCES FOR DEVELOPING WATER SUPPLIES Renewable Energy SourcesAdvantagesDisadvantagesCostApplicability in Virginia Direct Solar Energy (Stills) Affordable and easy to maintain, good efficiency Requires large land area and sunlight LowNot applicable as a significant energy source in Virginia - applicable for remote areas with lots of sunlight Indirect Solar Energy (Photovoltaic & Solar Collectors) Good energy collectors Low efficiency, and high manufacturing costs, requires large arrays Med. Has potential for use as a power supplement. Research is needed to increase efficiency and determine potential in Virginia Wind EnergyMature technology that can generate large amounts of energy Wind is intermittent?Applicable but may not have enough winds to be cost-effective in Virginia coastal areas. Research is needed to determine the potential. Geothermal Energy Large amounts of resources available in some areas Technology is undeveloped for application to desalination ?Not applicable as a significant energy source in Virginia - there are not enough geothermal reserves in Virginia Ocean Energy Tidal Tides occur at every coastline, fairly efficient Energy is intermittent HighApplicable but may not have enough difference in elevation between tides to be cost-effective. Research is needed to determine the potential. Ocean Energy Wave Cost effective for large plants, less expensive than diesel or hydropower Wave heights varyMed. Applicable Research is needed to determine the potential. Ocean Energy Thermal Research in progressFew areas where ocean has significant temperature variations with depth, expensive, low efficiency HighApplicable but not practical until technology is further improved and costs are decreased. Wind energy rotates windmills creating mechanical energy that can be converted to electrical energy. Turbines utilizing wind energy for low power (10 kW-100 kW), medium power (100 kW-0.5 MW), and high power (> 0.5 MW) are mature technologies. Location Power Generated (kW) Tech- nology Capacity (gal/d) Shark Bay, Australia32RO44380 & 34340 Borj-Cedria, Tunisia RO + ED Fuerteventura Island, Spain RO14794 Ile du Planier, France RO3170 Helgoland, Germany RO6086000 Ruegen Island, Germany200MVC31700-79250 Gran Canaria, Spain RO52830 Location Power Generated (kW)Technology Capacity (gal/d) Perth, Western Australia1.2RO634-3170 Jeddah, Saudi Arabia8RO845 North of Jawa, Indonesia25.5RO3170 Vancouver, Canada*4.8RO264 Red Sea, Egypt19.84RO13210 Hassi-Khebi, Argelie2.59RO6023