Introduction to CLEWs interlinkages

Integrated Assessments Integration of knowledge from different systems (e.g. water, energy, food, climate) into a single framework through the development of models that aim at representing the dynamics of resource systems and their interaction with its users. Advancing knowledge of systems, interactions between systems and implications across sectors Integrated assessments integrate knowledge from two or more domains into a single framework though the development of numerical models that aim at represent the dynamics of resources systems (supply and/or demand). They aim at inform policy making / design. Main goal of informing policy design

Assessing the climate, land(food), energy and water nexus Conflicts Trade-offs Opportunities Synergies Investigation of how resource systems interact. The CLEWs framework suggests this can be achieved quantitatively: with the development of sectoral systems models and integration and iteration between these; Using a single model framework (e.g. OSeMOSYS). Holger & Francesco:

How do systems interact?

Water & energy WATER ENERGY Energy needs water in all the different stages of electricity generation, not just in the operational phase (e.g. cooling) but also for fuel extraction, component manufacturing and power plant construction. WATER water systems rely on energy to operate at every stage, from water abstraction and production, diversion, treatment, use and disposal. ENERGY Water and energy are interlinked and depend on each other Energy sector's related activities require the use of water resources in all the different stages of electricity generation, not just in the operational phase but also for fuel extraction, component manufacturing and power plant construction. With 90% of worldwide energy systems highly dependent on water resources, the use of water is yet to be planned and operated in a more sustainable manner." The objective was to emphasize that although water is acknowledgely essential resource in energy generation, the way is is used in the related process could largely be more water efficient.92. On the other hand, water systems rely on energy to operate at every stage, from water abstraction and production, diversion, treatment, use and disposal. Another important interlinkage is the energy requirements of activities that imply the use of water, like cleaning and heating water. The description below focuses on how energy systems interact with water systems (energy to water), the latter incorporating both natural and artificial systems. The interlinkages were categorised in three types: energy for the operation of water systems; energy for the use of water; and, energy sector’s impact on water systems. 11/27/2018 Summer School on Modelling Tools for Sustainable Development 12-30 June 2017, ICTP, Trieste. Organizers: UNDESA, UNDP, ICTP, Cambridge University, KTH

Water to Energy WATER TO ENERGY Fuel cycle Fossil fuel extraction Fuel processing Biofuel cultivation and processing Energy conversion processes Transport sector Electricity generation hydropower Thermal power Non-hydro renewables Water to energy – transportation sector: Water intensity of the transport sector, which incorporates water used in fuel production and use, is related to the type of fuel used and the type of vehicle (Figure 2-23). Fuels derived from fossil fuels are less water intensive than biofuels or indirectly derived from fossil fuels, in the case of electricity. The efficiency of the vehicle affects the amount of fuel used and therefore the water consumption linked to this step 347. 11/27/2018 Summer School on Modelling Tools for Sustainable Development 12-30 June 2017, ICTP, Trieste. Organizers: UNDESA, UNDP, ICTP, Cambridge University, KTH

Water to Energy: water use, withdrawal and consumption Consumptive use: evaporation in cooling ponds and towers Non-consumptive: Return of withdrawn water Reservoirs and RoR Consumptive use: evaporation losses Non-consumptive: discharge The case of thermal power plants, including nuclear, is in turn more complex. In this case, it important to analyse water use in terms of withdrawals and consumption, which water use rates depend on the type thermal power generation (fuel and conversion technology) and on the cooling system technology used. For some cooling systems, withdrawals can be significant but could entail low consumption of water, while for others, e.g. cooling towers, the opposite happens. For the same cooling system, coal and nuclear power plants usually require more water for cooling purposes, while natural gas requires a lesser amount. Both consumptive and non-consumptive uses are relevant and may impact regional water availability and quality. The effects of such impacts vary according to the vulnerability of the water resources. 11/27/2018 Summer School on Modelling Tools for Sustainable Development 12-30 June 2017, ICTP, Trieste. Organizers: UNDESA, UNDP, ICTP, Cambridge University, KTH

Water for energy: electricity generation Evaporation HYDROPOWER PLANTS discharge WATER RESOURCES consumption Importante distincao é a terminologia associada à utilizacao de agua na producao de energia. A agua é utilizada de diferentes formas, o que nem sempre implica o seu consumo. Assim, neste ponto faz-se a distincao entre agua consumida e agua extraída. No caso das centrais hidroelectricas, a agua é turbinada para producao de energia electrica, pelo que este uso nao implica consumo, e a agua é devolvida para o meio natural, continuando o seu curso. Obviamente existem impactos a nivel dos ecosistemas relacionados com esta utilizacao. Já o seu “consumo” entendido como água que é perdida do fonte inicial e que nao se encontra a jusante para utilizacao, esta relacionado com perdas por evaporacao. No caso da utilizacao de agua por centrais termoelectricas, as fraccoes de extraccao e de consumo dependem de diversos factores: desde o tipo de combustivel utilizado, o tipo de tecnoligia de geracao, e o tipo de Sistema de arrefecimento. Focusing in waterThe main energy production technologies are dependent on water resources. Changes in availability of these will directly impact energy production facilities. The water use profile of each aforementioned technology is very different. In the case of hydropower plants, water losses may not be significant, with water consumption varying greatly according with the hydropower type. The existence of reservoirs is linked to higher water losses, which happen due to evapotranspiration. This type will be particularly susceptible to ambient air and river water temperature. Run-of-river hydropower plants are less prone to be affected by evapotranspiration but more sensitive to changes in precipitation patterns. The water use by thermal power plants varies significantly with the cooling technology used, and because of this, it is important to understand the different forms water can be used. As water is withdrawn, it can be consumed (and lost, not being returned to the water abstraction source, which happens mainly when cooling towers are used) or withdrawn and returned to the river (run-through and cooling-pond cooling systems). In the latter case, water consumption values are lower, and are mainly due to evaporation losses in result of the imposed increase of the water temperature. For example: Low flows affect hydropower production. Electricity demand will then have to be met through fossil fuel use (e.g. coal), increasing CO2 emissions. THERMAL POWER PLANTS withdrawal Return flow

Water for energy: thermal generation and cooling systems TYPE OF FUEL AND TECHNOLOGY Once-Through (m3MWh-1) 0.38 1.02 0.95 3.03 Tower 0.78 2.54 2.60 3.41 Fix the arrow animation. TYPE OF COOLING SYSTEM

Energy to water ENERGY TO WATER Operation of water systems pumping (extraction and distribution water purification wastewater treatment non-conventional production of potable water pump storage power plants Use of water Water heating Energy use and end use (e.g. washing machines) Energy for agriculture Irrigation systems Energy to water 11/27/2018 Summer School on Modelling Tools for Sustainable Development 12-30 June 2017, ICTP, Trieste. Organizers: UNDESA, UNDP, ICTP, Cambridge University, KTH

Water & Land WATER TO LAND URBAN AREAS & PLANNING Population distribution and location of water resources AGRICULTURE Crop suitability and yields Livestock Natural cover Forests Wetlands Inland water 11/27/2018 Summer School on Modelling Tools for Sustainable Development 12-30 June 2017, ICTP, Trieste. Organizers: UNDESA, UNDP, ICTP, Cambridge University, KTH

Group work Identifying CLEW challenges at national level Access google doc (in Country Data folder): Climate – land use – energy – water challenges 11/27/2018 Summer School on Modelling Tools for Sustainable Development 12-30 June 2017, ICTP, Trieste. Organizers: UNDESA, UNDP, ICTP, Cambridge University, KTH