The Water-Energy Nexus: From Crisis to Opportunity
description
Transcript of The Water-Energy Nexus: From Crisis to Opportunity
The Water-Energy Nexus: From Crisis to Opportunity
David EJ GarmanDean School of Freshwater Sciences
Overview
Brief overview of water and water quality issues from existing generation systems in USA look at alternative and emerging technologies in terms of water implicationsAn assessment of whether there is hope or not!
ENERGY AND WATER RELATIONSHIPSWATER FOR ENERGY
ENERGY FOR WATER
Hydropower
Thermo electric Cooling
Fuel Production (Ethanol, hydrogen)
Extraction & Refining
Extraction and Transmission
Drinking Water Treatment
Waste Water Treatment
Energy Associated with Uses of Water
USES OF WATER
WITHDRAWALS OF WATER
UNICEF Urban WASH workshop, October, 2009 Vörösmarty et al. 2000
• 80% of future stress from population & development, not climate change!
•Correct Priorities? (E.g. 85% US global change research funding to climate and carbon)
Water Stress Changes to 2025
UNH
WATER CONSUMPTION & ENERGY
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
Sources of power in USA 2006
Projected Water Use for PowerAssumptions• 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 WestMost of the growth occurs in areas of limited water availability Source EIA
Evaporation & Generation
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
ENERGY AND INTERACTIONS & ALTERNATIVE FUELS
Are we making the right decisions now in terms of water?
ENERGY AND WATER RELATIONSHIPSWATER FOR ENERGY
ENERGY FOR WATER
Hydropower
Thermo electric Cooling
Fuel Production (Ethanol, hydrogenmethane)
Extraction & Refining(Oil, sands, biofuels)
Extraction and Transmission
Drinking Water Treatment
Waste Water Treatment
Energy Associated with Uses of Water
Distribution and Collection
Source Virginia Water Resources Research Center 2006/2011
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
Water Related Electricity Use in California - 2001
Including Agriculture Without AgricultureGWh % GWh % KWh/pp
Water Supply and TreatmentUrban 7,554 16% 7,554 20% 218 Agricultural 3,188 7% 0%
End UsesAgricultural 7,372 15% 0%Residential 13,526 28% 13,526 36% 391 Commercial 8,341 17% 8,341 22% 241 Industrial 6,017 13% 6,017 16% 174
Wastewater Treatment 2,012 4% 2,012 5% 58
Total Water Related Energy Use 48,010 100% 37,450 100% 1,082
Total California Electricity Use 250,494 250,494 7,240
Water Related as % of Total 19% 15%
Population (Millions) 34.600
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
OTHER WATER IMPACTSMore than just the volume measure the quality
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
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
UNICEF Urban WASH workshop, October, 2009
Water Quality Challenges Add to the Complexity
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 challengeTraditional energy generation – coal fired has left a legacy of issues
The projected change is compared to the present day with a ~1% increase per year in equivalent CO2Source: The Met Office. Hadley
Center for Climate Prediction and Research
Projected Changes in Annual Temperatures for the 2050s
a global network for water professionals
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
Water Re-use Queensland
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
NEW TECHNOLOGIESHow quickly can these become large scale generation capacity
HIGH INTENSITY SOLAR SYSTEMS
Linkage to heat recovery systems and special use energy generation systems
Small scale generation at present.
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
Restructuring the InputsOptions• Integrated large, medium & small generation
systems• Multiple source generation Outcomes• Reduced water use• Increased flexibility
CONCLUSIONS
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
Acknowledgements
• Paul Reiter & IWA staff• Many colleagues members that contributed
slides
IWA - a global network for water professionals