Water and electricity are fundamentally linked. Policy reforms in both industries, however, do not appear to acknowledge the links nor consider their wider implications. This is clearly unhelpful, particularly as policy makers attempt to develop effective responses to water and energy issues, underpinned by prevailing drought conditions and impending climate change. Against this backdrop, this research has comprehensively analysed the links between water and electricity – termed water-energy nexus – in the context of New South Wales. For this purpose, this research has developed an integrated methodological framework. The philosophical guidance for the development of this framework is provided by Integral Theory, and its analytical foundations rest on a suite of research methods including historical analysis, inputoutput analysis, analysis of price elasticities, and long-term scenario analysis. This research suggests that the historical and inextricable links between water and electricity, in the absence of integrated policies, has given rise to water-energy trade-offs. In the electricity industry, water-intensive coal-fired power stations that dominate base-load capacity in the National Electricity Market has resulted in intra- and inter-jurisdictional water sharing tradeoffs. Intermediate and peak demand technologies, suchas gas-fired, cogeneration and renewables, however, would significantly reduce the industry’s water consumption and carbon emissions. Drought and climate change adaptation responses in the water industry are likely to further increase electricity demand andpotentially contribute to climate change, due to policies that encourage investment in energy-intensive technologies, such as desalination, advanced wastewater treatment and rainwater tanks. Increasing electricity costs due to water shortages and the introduction of emissions trading will futher increase water and electricity prices for end users. Demand management strategies in both industries will assist in curbing price increases, however, their effectiveness is lessened by investment in water- and energy-intensive technologies in both industries. The analysis also demonstrates that strategies to reduce water and electricity consumption of ‘other’ production sectors in New South Wales is overwhelmingly dependent on how deeply a particular sector is embedded in the economy, in terms of its contribution to economic output, income generation and employment growth. Regulation, demand management programs, and water pricing policies, for example, that reduce the water and energy intensity of agriculture and key manufacturing sectors are likely to benefit the wider economy and the Environment. The future implications of the water-energy nexus are examined through long-term scenario analysis for New South Wales for 2031. The analysis demonstrates how policy decisions shape the domain for making philosophical choices by society - in terms of the balance between relying on alternative technologies and market arrangements, with differing implications for water and electricity use, and for instigating behavioural change. Based on these findings, this research puts forward a range of recommendations, essentially arguing for reorienting existing institutional arrangements, government measures and industry activities in a way that would encourage integration between the water and energy policies. Although the context of this research is New South Wales, the findings are equally relevant for other Australian states, which share the same national water and energy policy frameworks. Further, the concepts and frameworks developed in this research are also of value to other countries and regions that are faced with the task of designing appropriate policy responses to redress their water and energy challenges.

Availability of and access to water and energy are key ingredients for economic and social development. Predictions show that pressure on already limited water and energy resources is expected to increase in many parts of the world as a result of growing populations, rapid urbanization, increasing pollution and climate change impacts. The water and energy systems are highly interdependent and these interlinks provide important opportunities to improve resource security and prevent inefficient decisions which could exacerbate problems even further. This thesis explores the benefits to be gained from and the drawbacks of ignoring the various interlinks. A review of several existing water-energy integration modeling methodologies shows that the different physical, temporal and spatial characteristics of the water and energy systems present several hurdles in analyzing the two resources simultaneously. This thesis overcomes many of these issues by developing a fully integrated hard-linked water-energy linear optimization model. A case study from Spain is used to demonstrate the applications of the model for simultaneous analysis of water, energy and climate change adaptation strategies. An integrated approach is shown to have several benefits including lower total costs, better resource efficiency and improved robustness for a wide range of variations in several uncertain parameters. / <p>QC 20171106</p>

This investigation posits the hypotheses: 1) Renewable energy is a viable economic alternative to current electricity sources on Grand Cayman and 2) focus on the water-energy nexus reveals positive synergies in water and energy economics on Grand Cayman.             These were investigated by examining the water-energy links of wastewater as a resource, and water produced from a hydrogen fuel cell. Conditions were varied including cost and efficiency factors to understand the limits of both links.             The results show that both hypotheses can be confirmed, though not in all circumstances. Longer project lifetimes increase the viability of renewable energy. Short lifetimes favour fossil-fuelled energy. Generally, water-energy linked thinking is economically favourable when the water is considered an additional product. The economic benefit of the hydrogen fuel cell is near-negligible due to low water flow rate. The economic benefit of wastewater as a resource is large, offsetting much of the costs of any project, particularly at long lifetimes. Both links provide societal benefits in the form of increased water availability. This increase is small for the hydrogen fuel cell water link, and large for the wastewater link. The wastewater link is however limited both by availability of wastewater, and acceptance of the direct reuse of treated wastewater.             It was determined that further investigation of these and other links are justified. The economic value of water-energy links is proven over a wide range of variabilities. Renewable energy has also been shown to be economically viable for the island of Grand Cayman.

A sustainable supply of fresh water for the human population is a global concern. Intriguingly, about 70% of the total fresh water consumed in the world annually is claimed by agriculture alone; this fraction is even higher in the Middle East and North Africa (MENA) region, where natural regeneration of groundwater is the slowest. Thus, there is a serious need for innovative materials and technologies to enhance the efficiency water usage in agriculture. To this end, plastic mulches have been employed across the developed world to minimize evaporative loss of water from top-soils. While plastic mulches are inexpensive, they do require specialized farm machinery for installation and long processing times. On one hand, plastic mulches have proven to increase crop yields, but on the other their non-biodegradability poses serious environmental concerns. In response, development of low-cost bio-/photo-degradable artificial mulches remains an area of intense research. In this thesis, we report on a novel superhydrophobic material exploiting inexpensive simple components to reduce the amount of water required for irrigation in agriculture by suppressing evaporative losses from the top-soil. Our material consists of ordinary beach sand coated with < 20 nm thick layer of paraffin wax. We synthesized and extensively characterized our material and applied them as mulches for tomato and barley plants at the KAUST greenhouse. We found that when a ~5 mm thick layer of superhydrophobic sand was placed onto the top-soil in pots, it dramatically suppressed evaporative losses and significantly enhanced the yields. Our preliminary field-scale experiments with tomatoes and barley crops at the Hada Al Sham site corroborate these results. Our approach might find applications in desert agriculture and other fields and alleviate water stress in the MENA region.

abstract: To improve the resilience of complex, interdependent infrastructures, we need to better understand the institutions that manage infrastructures and the work that they do. This research demonstrates that a key aspect of infrastructure resilience is the adequate institutional management of infrastructures. This research analyzes the institutional dimension of infrastructure resilience using sociotechnical systems theory and, further, investigates the critical role of institutions for infrastructure resilience using a thorough analysis of water and energy systems in Arizona. Infrastructure is not static, but dynamic. Institutions play a significant role in designing, building, maintaining, and upgrading dynamic infrastructures. Institutions create the appearance of infrastructure stability while dynamically changing infrastructures over time, which is resilience work. The resilience work of different institutions and organizations sustains, recovers, adapts, reconfigures, and transforms the physical structure on short, medium, and long temporal scales. To better understand and analyze the dynamics of sociotechnical infrastructure resilience, this research examines several case studies. The first is the social and institutional arrangements for the allocation of resources from Hoover Dam. This research uses an institutional analysis framework and draws on the institutional landscape of water and energy systems in Arizona. In particular, this research illustrates how institutions contribute to differing resilience work at temporal scales while fabricating three types of institutional threads: lateral, vertical, and longitudinal threads. This research also highlights the importance of institutional interdependence as a critical challenge for improving infrastructure resilience. Institutional changes in one system can disrupt other systems’ performance. The research examines this through case studies that explore how changes to water governance impact the energy system in Arizona. Groundwater regulations affect the operation of thermoelectric power plants which withdraw groundwater for cooling. Generation turbines, droughts, and water governance are all intertwined via institutions in Arizona. This research, finally, expands and applies the interdependence perspective to a case study of forest management in Arizona. In a nutshell, the perilous combination of chronic droughts and the engineering resilience perspective jeopardizes urban water and energy systems. Wildfires caused by dense forests have legitimized an institutional transition, from thickening forests to thinning trees in Arizona. / Dissertation/Thesis / Doctoral Dissertation Environmental Social Science 2019

The issues of conflicts between water, energy and food (often referred to as WEFnexus) has become a problem in countries where the energy system is rapidly expanding; one of those countries is Ethiopia. Ethiopia has a large potential of hydropower, which is what most of the electricity production currently comes from. However, this has proven to cause problems on other practices around or close to the power plants. An example is the Omo River basin where the development of the Gibe hydropower cascading scheme, with currently the three power plants Gibe I, I and III operating, have brought up the discussion of the downstream impact. For instance, indigenous people living in the lower parts of Omo river, practice flood recession agriculture, meaning they are depending on the seasonal floods. Further, Omo river has its outflow into Lake Turkana, Kenya, and the lake is highly dependent on the flow regime of the Omo river. Studies on the Omo river have been many, an example is the ones using Topkapi-ETH, a physically based rain-fall runoff model, that models the hydrological aspects of the river and considers, among others, water abstraction for irrigation and diversions to reservoirs for hydropower. However, the hydropower modelled worked on the basis of an averaged power demand; not necessarily reflect the actual demand. Hence, OSeMOSYS, the long-term energy optimization tool, was proposed to complement this study by modelling the energy system in Ethiopia. This current thesis had the aim to do so with the attempt to explore the possibility of a coupling between the models Topkapi-ETH and OSeMOSYS. The aim was to feed OSeMOSYS with varying water availability from Topkapi-ETH; in return, OSeMOSYS would feed Topkapi-ETH with a more realistic required energy production demand. An OSeMOSYS model was set up for Ethiopia, with national data extracted from the study The Electricity Model Base for Africa (TEMBA), disaggregating the hydropower to be able to model each of the hydropower plants in the Gibe cascading scheme individually. To couple the two models, two approaches were developed: Storage module and Reservoir module. The Storage module used the storage feature within OSeMOSYS and used the varying volume in the reservoir from Topkapi-ETH and converted it into an energy potential, as input to OSeMOSYS. The Reservoir module, on the other hand, used the external inflow (sum of all flows except upstream release), obtained from Topkapi-ETH, to the reservoir. An experimental set-up was performed to test how the OSeMOSYS model, with the two modules, would react to the input and which inputs were the driving forces affecting the electricity production. The results showed that OSeMOSYS can respond to the varying water availability received from Topkapi-ETH with the electricity production from the Gibe cascading scheme showed results reflecting this. However, there was a mismatch in the hydrological response in which OSeMOSYS did not seem to fully reflect the volume in the reservoir. For certain cases, the volume would be zero, indicating it would not store any water but instead use all incoming water directly for energy production. Hence, with respect to the results presented in this study, one can conclude that OSeMOSYS is prone to respond to changes in water availability. However, due to the incompatibility in the hydrological perspective in regard to the volume, the coupling is not complete. Before such a complete coupling can be achieved one needs to understand why OSeMOSYS does not reflect the hydrological characteristics. If this can be solved, then a feedback of the required energy production in the Gibe hydropower plants ought to be sent back to Topkapi-ETH. / Konflikten mellan vatten, energi och mat (ofta benämnt WEF-nexus) har blivit ett problem i länder där energisystemet snabbt utvecklas; ett av dessa länder är Etiopien. Etiopien har stor potential i vattenkraft, från vilket den största delen av elektriciteten kommer ifrån idag. Däremot har detta visat skapa problem kring andra verksamheter runtomkring eller i närheten av kraftverken. Ett exempel är Omo RIVER BASIN, beläget i sydvästra Etiopien. Exploateringen av Gibe vattenkraftverk i en kaskad schema, idag med de tre kraftverket Gibe I, IO och III i bruk, har skapat diskussion kring påverkan nedströms. Till exempel så bot Urbefolkningen i den nedre delen av Omo floden, där de utövar så kallad flood recession jordbruk, vilket innebär att de är beroende av säsonger av översvämningar för att bevattna marken. Vidare, Omo floden har sitt utflöde in i Lake Turkana, Kenya, och skön är starkt beroende av flödesregimen i Omo floden. Studier kring Omo floden har varit manga, ett exempel är de som har använt sig av Topkapi-ETH, en fysikaliskt baserad nederbörd yt-avrinnings modell, som modellerat de hydrologiska aspekterna I floden och tar hänsyn till, bland annat, extrahering av vatten i bevattningssyfte och diversion till vattenkraftsdam. Dock modellerade vattenkraftverken med utgångspunkt från ett uppskattat energibehov; nödvändigtvis inte det faktiska behovet. Således föreslogs att OSeMOSYS, en LONGTERM energi optimerings modell, skulle komplimentera denna studie genom att modellera energisystemet i Etiopien. Den här uppsatsen hade som avsikt att testa de föregående med en ansats att undersöka möjligheten att sammankoppla de två modellerna Topkapi-ETH and OSeMOSYS. Målet var att förse OSeMOSYS med en varierad vatten tillgänglighet från Topkapi-ETH; i retur skulle OSeMOSYS förse Topkapi-ETH med ett mer realistiskt energiproduktions behov. En modell i OSeMOSYS skapades för Etiopien, med nationella data extraherad från studien The Electricity Model Base for Africa (TEMBA), där vattenkraftverk disaggregerades för att kunna modellera varje kraftverk I Gibe kaskad schema enskilt. För att sammankoppla de två modeller skapades två tillvägagångssätt: Lagrings modul och Reservoar modul. Magasin modulen använde en lagrings funktion i OSeMOSYS med en funktion av den varierande volym i en reservoar från Topkapi-ETH som omvandlades till en potentiell energi. Reservoar modulen däremot använde externt inflöde (summan av alla flöden förutom upströms utflöde), taget från Topkapi-ETH till reservoaren. Ett försök sattes upp för att testa hur OSeMOSYS modellen, med de två modulerna, skulle reagera till indata och vilken indata som är drivande och påverkar produktionen av elektricitet. Resultaten visade att OSeMOSYS kan besvara ett varierade vatten tillgänglighet kommen från Topkapi-ETH där produktionen av elektricitet från Gibe kaskad schema återspeglade detta. Däremot fanns en missanpassning i den hydrologiska responsen där OSeMOSYS inte fullt ut avspeglade volymen i reservoaren. I vissa fall var volymen noll, vilket tyder på att inget vatten kan lagras utan allt inkommande vatten går direkt till turbiner för produktion av energi. Således, med avseende på resultaten presenterade i den här studien, kan en dra slutsatsen att OSeMOSYS kan svara på variationer i vatten tillgängligheten. Däremot, på grund av missanpassning i hydrologiska perspektivet med avseende på volmen, så är inte sammankopplingen mellan modellerna fullständig. Före en sådan fullständig sammankoppling kan uppnås måste en förstår varför OSeMOSYS inte återspeglar denna hydrologiska karaktär. Om detta kan förstås, så kan en feedback av den fordrade energiproduktionen i Gibe vattenkraftverken återsändas tillbaka till Topkapi-ETH.

No description available.

Residential water heating is linked to the primary source of waterborne disease outbreaks in the United States, and accounts for greater energy demand than the combined water/wastewater utility sector. To date, there has been little research that can guide decision-making with regards to water heater selection and operation to minimize energy costs and the likelihood of waterborne disease. We have outlined three types of systems that currently dominate the marketplace: 1) a standard hot water tank with no hot water recirculation (STAND), 2) a hot water tank with hot water recirculation (RECIRC), and 3) an on-demand tankless hot water system with no hot water recirculation (DEMAND). Not only did the standard system outperform the hot water recirculation system with respect to temperature profile during flushing, but STAND also operated with 32 – 36% more energy efficiency. Although RECIRC did in fact save some water at the tap, when factoring in the energy efficiency reductions and associated water demand, RECIRC actually consumed up to 7 gpd more and cost consumers more money. DEMAND operated with virtually 100% energy efficiency, but cannot be used in many circumstances dependent on scaling and incoming water temperature, and may require expensive upgrades to home electrical systems. RECIRC had greater volumes at risk for pathogen growth when set at the lower end of accepted temperature ranges, and lower volumes at risk when set at the higher end when compared to STAND. RECIRC also tended to have much lower levels of disinfectant residual (40 -850%), 4-6 times as much hydrogen, and 3-20 times more sediment compared to standard tanks without recirculation. DEMAND had very small volumes of water at risk and relatively high levels of disinfection. A comparison study of optimized RECIRC conditions was compared to the baseline modes of operation. Optimization increased energy efficiency 5.5 – 60%, could save consumers 5 – 140% and increased the disinfectant residual up to 560% higher disinfectant residual as compared to the baseline RECIRC system. STAND systems were still between 3 – 55% more energy efficient and could save consumers between $19 - $158 annual on water and electrical costs. Thus, in the context of “green” design, RECIRC systems provide a convenience to consumers in the form of nearly instant hot water, at a cost of higher capital, operating and overall energy costs. / Ph. D.

Rainwater harvesting (RWH) refers to the collection of rainwater for subsequent on-site use. Rainwater is most often used for non-potable purposes including toilet flushing, laundering, landscape and commercial crop irrigation, industry, fire fighting, air-conditioning, and vehicle-washing. This study evaluates the potential impacts of RWH on residential housing on Virginia Tech campus in southwestern Virginia in regards to potable water offset, energy conservation, stormwater mitigation, carbon emission reduction, and financial savings. Potential rainwater collection was estimated from three simulations used to approximate the maximum, average, and minimum range of annual precipitation. Collected rainwater estimates were used to calculate the impacts on the areas of interest. Cumulatively, the sample buildings can collect 3.4 to 5.3 millions of gallons of rainwater — offsetting potable water use and reducing stormwater by an equivalent amount, save 320 to 1842 kWh of energy, and reduce carbon emissions by 650 to 3650 pounds annually. Cumulative savings for the nine buildings from combined water and energy offsets range between $5751 and $9005 USD, not substantial enough to serve as the sole basis of RWH implementation on campus. A significant advantage of RWH relates to the management and improvement of the Stroubles Creek watershed in which the majority of the campus sits. Additionally, RWH implementation would benefit sustainable initiatives and provide Virginia Tech additional opportunities for conservation incentives and environmental stewardship funding. / Master of Science

Wastewater Treatment Plants (WWTPs) are sophisticated systems that have to sustain long-term qualified performance, regardless of temporally volatile volumes or compositions of the incoming wastewater. Membrane filtration in the Membrane Bioreactors (MBRs) reduces the WWTPs footprint and produces effluents of proper quality. The energy or electric power consumption of the WWTPs, mainly from aeration equipment and pumping, is directly linked to greenhouse gas emission and economic input. Biological treatment requires oxygen from aeration to perform aerobic decomposition of aquatic pollutants, while pumping consumes energy to overcome friction in the channels, piping systems, and membrane filtration. In this thesis, we researched full-scale WWTPs Influent Conditions (ICs) monitoring and forecasting models to facilitate the energy consumption budgeting and raise early alarms when facing latent abnormal events. Accurate and efficient forecasts of ICs could avoid unexpected system disruption, maintain steady product quality, support efficient downstream processes, improve reliability and save energy. We carried out a numerical study of bioreactor microbial ecology for MBRs microbial communities to identify indicator species and typical working conditions that would assist in reactor status confirmation and support energy consumption budgeting. To quantify membrane fouling and cleaning effects at various scales, we proposed quantitative methods based on Matern covariances to analyze biofouling layer thickness and roughness obtained from Optical Coherence Tomography (OCT) images taken from gravitydriven MBRs under various working conditions. Such methods would support practitioners to design suitable data-driven process operation or replacement cycles and lead to quantified WWTPs monitoring and energy saving. For future research, we would investigate data from other full-scale water or wastewater treatment process with higher sampling frequency and apply kernel machine learning techniques for process global monitoring. The forecasting models would be incorporated into optimization scenarios to support data-driven decision-making. Samples from more MBRs would be considered to gather information of microbial community structures and corresponding oxygen-energy consumption in various working conditions. We would investigate the relationship between pressure drop and spatial roughness measures. Anisotropic Matern covariance related metrics would be adopted to quantify the directional effects under various operation and cleaning working conditions.