1.Quantification ofWater Energy and Carbon Nexus Kathmandu, Nepal 2529 September, 2012Dr. Sangam ShresthaAsian Institute of Technology (AIT), Thailand

2. Session objectives To understand how water energy and carbonemission are linked To estimate the energy use for water services, wateruse for energy production and carbon emissions To present and discuss about the water energy andcarbon nexus by considering hypothetical example 3. Outline Water Energy and Carbon nexus: Overview Cyclic effect of water energy and carbon nexus Energy uses for water services Water use for energy productions Water energy and carbon emission Example Exercises 4. Water Energy and Carbon Nexus Water and Energy has symbiotic relationship. Production and consumption of water involve energy useand energy production require water for consumptive aswell as non- consumptive use. Energy associated with water use is also responsible foremission of GHG. Clean energy adopted for reduction of GHG may havesubstantial water requirements hence water-energy-carbon nexus should be quantified more precisely forresource use optimization. Saving water is saving energy saving energy reducesemission of GHG. 5. Water Energy and Carbon NexusSource: US Department of Energy, December 2006. 6. Impact on climate(climate change)Water for EnergyWater Scarcity in city Energy For Water More Water / More Energy/More CarbonFigure: WEC Nexus in City and its Implications 7. Why do we need to knowWater Energy and Carbon Nexus? The rapid increase in population and extensive economicdevelopment in cities has increased the demand foradequate amount of water and energy. An increase inwater use requires more energy and demand for moreenergy in turn requires more water. Both of this hasimpact on GHG emissions. The challenge of climate change and reduction of GHGemissions and stabilize their levels in the atmosphere isglobally recognized. Integration of water and energy policies into a singleframework is necessary for resource use optimization andthis in turn demand proper estimation of water energyand carbon linkage. 8. Cyclic Effect of WEC NexusIncrease in urbanpopulationIncrease in waterDemandMore EnergyRequired for Waterproduction in City Increase in Energyconsumption as well as demandNew Wateralternatives Groundwater Desalinization More use of fossil fuel Inter Basin transferGlobal Warming /Climate changeIncrease in GHG Draught Emission Need more waterdue totemperature rise 9. Water footprint of energy A water footprint is the amount of water consumed byany sector for their purpose. Water is required forconsumptive as well as non consumptive use in powergeneration process, as source of kinetic energy inhydropower and coolant in case of nuclear and thermalplant. Water is used at various stages of the power generationcycle, including fuel extraction (mining and refining, oil,gas, uranium and coal processing, coal and gasliquefaction and gasification, carbon sequestration) andgeneration (coal, gas, oil, nuclear and biomass powerplants). 10. Water Use for EnergyTABLE: WATER USE FACTOR FOR DIFFERENT SOURCE OFELECTRICITY Electric Fuel Total Water Use(Litres/MWh)Withdrawal ConsumptionCoal 60,763 2,620Natural Gas24,545 651Nuclear56,066 2,165Solar Thermal 3,028 3,028Geothermal2,650 2,650Photovoltaic Solar874 8Wind