1. The Water-Energy Nexus: From Crisis to Opportunity David EJ Garman Dean School of Freshwater Sciences

2. Overview Brief overview of water and water quality issues from existing generation systems in US A look at alternative and emerging technologies in terms of water implications An assessment of whether there is hope or not!

5. ENERGY AND WATER RELATIONSHIPS WATER FOR ENERGY Extraction & Refining Hydropower Fuel Production (Ethanol, hydrogen) Thermo electric Cooling Waste Water Treatment Extraction and Transmission Drinking Water Treatment Energy Associated with Uses of Water ENERGY FOR WATER

6. USES OF WATER

7. WITHDRAWALS OF WATER

8. UNICEF Urban WASH workshop, October, 2009 Water Stress Changes to 2025 • •80% of future stress from • population • & development, • notclimate change! • Correct Priorities? • (E.g. 85% US global change • research funding to • climate and carbon) Vörösmarty et al. 2000 UNH

10. Water consumption & energy

12. US Power Water Use 2003 • Thermal water cooled - 87% • Evaporation 2.5% or 3310 million gals/day • 0.47 gal/kWh of power(1.8L/kWh) • Hydroelectricity - 9% • Evaporation – not given • Renewables – 4% • Water consumption - low Source: Torcellini et al. 2003 NREL/TP-550-33905

13. Sources of power in USA 2006

16. Projected Water Use for Power Assumptions • US population grows by 70 from 2006 to 2031 (25 years) • Electricity demand grows by 50% • Other laws/regs/policies/technology/consumer preferences - business as usual • Most growth in SE, SW and far West Most of the growth occurs in areas of limited water availability Source EIA

17. Evaporation & Generation

18. Evaporative Cooling Consumption • 89% US electricity is produced with thermally driven water-cooled energy conversion cycles. • Evaporative or consumptive use is ~2.5% or 3,310 MGD (12,530 ML/d). • Hydroelectric plants produce ~ 9% electricity. • In thermoelectric plants, 0.47 gal (1.8 L)/kWhr • Hydroelectric plants 18 gal (68 L)/kWhr • Weighted average TE & HE water use is 2.0 gal (7.6 L) per kWh

19. Are we making the right decisions now in terms of water? Energy and interactions & Alternative fuels

20. ENERGY AND WATER RELATIONSHIPS WATER FOR ENERGY Extraction & Refining (Oil, sands, biofuels) Hydropower Fuel Production (Ethanol, hydrogen methane) Thermo electric Cooling Waste Water Treatment Extraction and Transmission Distribution and Collection Drinking Water Treatment Energy Associated with Uses of Water ENERGY FOR WATER

21. Source Virginia Water Resources Research Center 2006/2011

22. Alternative fuels Fuel ethanol – 32 to 376 L /kWh depending on source Fuel from water rich areas transferred to water poor areas provides a transfer of virtual water

24. MULTIPLE (AND COMPLENTARY) APPROACHES TO EFFICIENCY GAINS IN WATER SYSTEMS User Side - Optimization Utility interventions at the end-use levels Appliance standards Building standards Quasi-market mechanisms Both Sides – System and Building Rethink at the City Level Densification Water-energy integration Water plants as energy and water factories Closing the loop -- water sensitive design Production – Extraction & Transmission,DW Treatment and WW Treatment • Efficient pumps • More efficient processes • Energy recovery from wastewater treatment

25. More than just the volume measure the quality Other water impacts

26. Issues of Power Production • Loss of habitat • Loss of fish, fish eggs and larvae • Thermal impact of discharges – good and bad • Cold water from hydro systems • Sediment discharges • Decommissioning of dams • Warm water from cooling • Changes in water quality from use

27. Fuels as a source of pollution • Coal – typically sulphur, particulates, mercury and trace metals, dioxins and ash leachates • Modern plants remove these at source after combustion • Coal gasification is an option • Pulverized coal injection is a major improvement for coal quality and combustion efficiency • Clean coal - equivalent to natural gas is still not an option • Most water quality issues other than thermal and CO2 are now historical, albeit persistent in some areas

28. UNICEF Urban WASH workshop, October, 2009 Traditional pollutants, micropollutants, and nutrients associated with urban, agricultural, and industrial use are also a key part of the challenge we face. Global warming exacerbates this challenge Traditional energy generation – coal fired has left a legacy of issues Water Quality Challenges Add to the Complexity

29. Projected Changes in Annual Temperatures for the 2050s The projected change is compared to the present day with a ~1% increase per year in equivalent CO2 Source: The Met Office. Hadley Center for Climate Prediction and Research

30. Related Water & Energy Impacts Water Shortages - exacerbated Flooding – changes to frequency and intensity Water Quality impacts from acidification and trace contaminants Sea levels rise and lake levels fall Increased competition a globalnetworkfor water professionals

31. Water Re-use Queensland

32. Due to water shortage $6.4 b was spent on a recycle system in Queensland including a a desalination plant. A major commitment was to supply water to power stations

33. How quickly can these become large scale generation capacity New technologies

34. HIGH INTENSITY SOLAR SYSTEMS Linkage to heat recovery systems and special use energy generation systems Small scale generation at present.

35. New technologies • Tri stage gas and geothermal (gas) • Photovoltaic • Heat recovery systems (household & commercial) • Fuel cells – hydrogen based • New battery systems linked to solar • High intensity solar • Microbial fuel cells • Carbon sequestration

36. Restructuring the Inputs Options • Integrated large, medium & small generation systems • Multiple source generation Outcomes • Reduced water use • Increased flexibility

37. conclusions

38. Conclusions • It is likely that water availability will be a driver to change generation location and technology and improve water use efficiency • Improvements to water use reduction include overall reductions in energy consumption • New technologies can offset water quantity and quality losses but a re-think is required to enable rapid uptake

39. IWA - a globalnetworkfor water professionals Acknowledgements • Paul Reiter & IWA staff • Many colleagues members that contributed slides