Standalone Photovoltaic Direct Pumping in Urban Water Pressurized Networks with Energy Storage in Tanks or Batteries

[EN] Photovoltaic energy production is nowadays one of the hottest topics in the water industry as this green energy source is becoming more and more workable in countries like Spain, with high values of irradiance. In water pressurized systems supplying urban areas, they distribute energy consumption in pumps throughout the day, and it is not possible to supply electromechanical devices without energy storages such as batteries. Additionally, it is not possible to manage energy demand for water consumption. Researchers and practitioners have proven batteries to be reliable energy storage systems, and are undertaking many efforts to increase their performance, capacity, and useful life. Water pressurized networks incorporate tanks as devices used for accumulating water during low consumption hours while releasing it in peak hours. The compensation tanks work here as a mass and energy source in water pressurized networks supplied with photovoltaic arrays (not electricity grids). This work intends to compare which of these two energy storage systems are better and how to choose between them considering that these two systems involve running the network as a standalone pumping system without being connected to electricity grids. This work also calculates the intermediate results, considering both photovoltaic arrays and electricity grids for supplying electricity to pumping systems. We then analyzed these three cases in a synthetic network (used in earlier research) considering the effect of irradiation and water consumption, as we did not state which should be the most unfavorable month given that higher irradiance coincides with higher water consumption (i.e., during summer). Results show that there is no universal solution as energy consumption depends on the network features and that energy production depends very much on latitude. We based the portfolio of alternatives on investments for purchasing different equipment at present (batteries, pipelines, etc.) based on economic criteria so that the payback period is the indicator used for finding the best alternative, which is the one with the lowest value.This work was supported by the research project "GESAEN" through the 2016 call of the Vicerrectorado de Investigacion, Desarrollo e Innovacion from the University of Alicante, GRE-16-08.Pardo, MA.; Cobacho Jordán, R.; Bañón, L. (2020). Standalone Photovoltaic Direct Pumping in Urban Water Pressurized Networks with Energy Storage in Tanks or Batteries. Sustainability. 12(2):1-20. https://doi.org/10.3390/su12020738S120122Bijl, D. L., Bogaart, P. W., Kram, T., de Vries, B. J. M., & van Vuuren, D. P. (2016). Long-term water demand for electricity, industry and households. Environmental Science & Policy, 55, 75-86. doi:10.1016/j.envsci.2015.09.005Breadsell, J. K., Byrne, J. J., & Morrison, G. M. (2019). 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Economic and Efficient Voltage Management Using Customer-Owned Energy Storage Systems in a Distribution Network With High Penetration of Photovoltaic Systems. IEEE Transactions on Power Systems, 28(1), 102-111. doi:10.1109/tpwrs.2012.2196529Pardo, M. Á., Manzano, J., Valdes-Abellan, J., & Cobacho, R. (2019). Standalone direct pumping photovoltaic system or energy storage in batteries for supplying irrigation networks. Cost analysis. Science of The Total Environment, 673, 821-830. doi:10.1016/j.scitotenv.2019.04.050Batchabani, E., & Fuamba, M. (2014). Optimal Tank Design in Water Distribution Networks: Review of Literature and Perspectives. Journal of Water Resources Planning and Management, 140(2), 136-145. doi:10.1061/(asce)wr.1943-5452.0000256Kurek, W., & Ostfeld, A. (2013). Multi-objective optimization of water quality, pumps operation, and storage sizing of water distribution systems. Journal of Environmental Management, 115, 189-197. doi:10.1016/j.jenvman.2012.11.030Sarbu, I. 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Unreported leaks location using pressure and flow sensitivity in water distribution networks

[EN] Water distribution systems are made up of many interdependent elements that enable water supply to meet a demand that is variable in time and space. One of the main concerns for utility managers is quickly locating and repairing a leak after detection, during regular network water balance. This paper presents a two-stage methodology for locating a leak that is based on the hydraulic model of the network, and, particularly, on the conservation equations that govern network behaviour. In the first stage, the sensitivity of each element (nodes and pipes) is obtained for a given demand increase in any node. In the second stage, that sensitivity is combined with additional real data provided by the (possibly) existing pressure sensors and flowmeters installed throughout the network. As a final result, the system of equations thus obtained produces the theoretical leak flow at each network node that matches the network conditions. A subsequent analysis of the leak flows obtained highlights the node or nodes in which the leak is occurring. The presented methodology is applied and assessed in a case study.Salguero Barceló, FJ.; Cobacho Jordán, R.; Pardo Picazo, MA. (2019). Unreported leaks location using pressure and flow sensitivity in water distribution networks. Water Science & Technology: Water Supply. 19(1):11-18. https://doi.org/10.2166/ws.2018.048S111819

Water End Use Disaggregation Based on Soft Computing Techniques

[EN] Disaggregating residential water end use events through the available commercial tools needs a great investment in time to manually process smart metering data. Therefore, it is extremely difficult to achieve a homogenous and sufficiently large corpus of classified single-use events capable of accurately describe residential water consumption. The main goal of the present paper is to develop an automatic tool that facilitates the disaggregation of the individual water consumptions events from the raw flow trace. The proposed disaggregation methodology is conducted through two actions that are iteratively performed: first, the use of an advanced two-step filter, whose calibration is automatically conducted by the Elitist Non-Dominated Sorting Genetic Algorithm NSGA-II; and second, a cropping algorithm based on the filtered water consumption flow traces. As a secondary goal, yet complementary to the main one, a semiautomatic massive classification process has been developed, so that the resulting single-use events can be easily categorized in the different water end uses in a household. This methodology was tested using water consumption data from two different case studies. The characteristics of the households taken as reference and their occupants were unequivocally dissimilar from each other. In addition, the monitoring equipment used to obtain the consumption flow traces had completely different technical specifications. The results obtained from the processing of the two studies show that the automatic disaggregation is both robust and accurate, and produces significant time saving compared to the standard manual analysis.This study has received funding by the IMPADAPT project /CGL2013-48424-C2-1-R from the Spanish ministry MINECO with European FEDER funds and from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 619172 (SmartH2O: an ICT Platform to leverage on Social Computing for the efficient management of Water Consumption).Pastor-Jabaloyes, L.; Arregui De La Cruz, F.; Cobacho Jordán, R. (2018). Water End Use Disaggregation Based on Soft Computing Techniques. Water. 10(1). https://doi.org/10.3390/w10010046S10

A filtering algorithm for high-resolution flow traces to improve water end-use analysis

[EN] One of the main difficulties encountered when designing automatic tools for water end use identification is the inherent noise present in recorded flow traces. Noise is mainly caused by the inability of the monitoring equipment to accurately register water consumption and data-loggers to register, without distortion, the signal received from the water meter. A universal filtering algorithm has been developed to remove noise and simplify water consumption flow traces with the aim of improving future automatic end use identification algorithms. The performance of the proposed filtering methodology is assessed through the analysis of 21,647 events. Water consumption data were sourced from two different water end use studies, having consumers and monitoring equipment with dissimilar characteristics. The results obtained show that the algorithm is capable of removing an average of 70% of the data points that constitute the flow traces of the complex events examined. The simplified flow traces allow for faster and more accurate disaggregation and classification algorithms, without losing significant information or distorting the original signal. The ability of the proposed filtering algorithm to fit the original flow traces was benchmarked using the Kling-Gupta efficiency coefficient, obtaining an average value above 0.79.This study has received funding by the IMPADAPT project/CGL2013-48424-C2-1-R from the Spanish ministry MINECO with European FEDER funds and from the European Union's Seventh Framework Programme (FP7/2007e2013) under grant agreement no. 619172 (SmartH2O: an ICT Platform to Leverage on Social Computing for the Efficient Management of Water Consumption).Pastor-Jabaloyes, L.; Arregui De La Cruz, F.; Cobacho Jordán, R. (2018). A filtering algorithm for high-resolution flow traces to improve water end-use analysis. Water Science & Technology: Water Supply. 19(2):451-462. https://doi.org/10.2166/ws.2018.090S45146219

Analytical hierarchical process (AHP) as a decision support tool in water resources management

©IWA Publishing 2011. The definitive peer-reviewed and edited version of this article is published in Acqua Journal of Water Supply: Research and Technology, 60 6 p.343-351 2011 DOI 10.2166/aqua.2011.016 and is available at www.iwapublishing.com.Despite advances in water conservation, abstraction and transport, water demand has been increasing worldwide in the past few decades. This has resulted in an increased pressure on stakeholders to provide sustainable solutions to meet future water demands. The decision-making process to find those solutions is becoming increasingly complicated. First, owing to the arrival of new technologies or the evolution of existing ones, the number of available alternatives has increased. Additionally, economic criteria have been abandoned as the sole reference for the comparison of alternatives. The increase of both options and restrictions has complicated significantly the choice of the best alternative. Until now, the search for solutions has usually focused on the reduction of all parameters and restrictions to a common denominator or the use of complex and scarcely transparent models. This paper shows how to make use of the AHP technique to improve the decision-making process in order to satisfy new water demands in a local context. This methodology has been widely used in other fields and allows the combination of quantitative and qualitative criteria. Among the virtues of AHP are transparency, simplicity and the fact that it relies on actual opinions from experts. © IWA Publishing 2011.The Ministry of Education and Science of Spain through Project No CGL2008-01910/BTE has supported this research.Cabrera Rochera, E.; Cobacho Jordán, R.; Estruch Guitart, V.; Aznar Bellver, J. (2011). Analytical hierarchical process (AHP) as a decision support tool in water resources management. Journal of water supply : research and technology - Aqua. 60(6):343-351. https://doi.org/10.2166/aqua.2011.016S34335160

Standalone direct pumping photovoltaic system or energy storage in batteries for supplying irrigation networks. Cost analysis

[EN] Solar photovoltaic systems have become one of the most popular topics in the water management industry. Moreover, irrigation networks are water- and energy-hungry, and utilitymanagers are likely to adaptwater consumption (and consequently energy demand) to the hours inwhich there is energy availability. In countries such as Spain (with high irradiance values), solar energy is an available green alternative characterised by zero electricity costs and significantly lower environmental impact. In this work, several types of irrigation scheduled programmes (according to different irrigation sectors) that minimise the number of photovoltaic solar panels to be installed are studied; moreover, the effects of the variable costs linked to energy (energy and emissions costs) are presented. Finally, the effect of incorporating batteries for storing energy to protect the system against emergencies, such as unfavourable weather, is proposed. The irrigation hours available to satisfywater demands are limited by sunlight; they are also limited by the condition that the irrigation schedule type has to be rigid (predetermined rotation) and that the pressure at any node has to be above minimumpressure required by standards. A real case study is performed, and the results obtained demonstrate that there is no universal solution; this is because the portfolio of alternatives is based on investments for purchasing equipment at present and also on future energy savings (revenues). Apart from these two values, there is an economic value (equivalent discontinuous discount rate), which also influences the final results.This work was supported by the research project “GESAEN” through the 2016 call of the Vicerrectorado de Investigación, Desarrollo e Innovación de la Universidad de Alicante GRE-16-08.Pardo Picazo, MA.; Manzano Juarez, J.; Valdes-Abellan, J.; Cobacho Jordán, R. (2019). Standalone direct pumping photovoltaic system or energy storage in batteries for supplying irrigation networks. Cost analysis. The Science of The Total Environment. 673:821-830. https://doi.org/10.1016/j.scitotenv.2019.04.050S82183067

A Front-Line and Cost-Effective Model for the Assessment of Service Life of Network Pipes

[EN] In any water utility, a reliable assessment of the service life of the network pipes is a key piece within the big puzzle of assets management. This paper presents a new statistical model (basic pipes life assessment, BPLA) to assess the service life of pipes, to locate the pipes on the failures bath curve and to forecast the expected failures in future years. Its main novelties are the processing of pipe information (is that information what is adapted to the classical maintenance engineering and not the other way back) and the definition of two different time variables that can be analyzed in parallel. The first novelty makes the model less demanding in terms of data and software tools than others currently available, and the second one allows to get all the results after one single stage of calculation. To show its usability, the BPLA has been applied to a pipe network that supplies water to 500,000 citizens for which two years of failure records are available. Procedures and results have been compared to the well-known Weibull proportional hazard model (WPHM), with final relative errors lower than 10% and 15% on each particular result.The authors would like to thank Global Omnium for the support provided, both directly and through the Catedra Aguas de Valencia of the UPV, for the development of the works presented in this paper.Ramírez-Aguilar, RX.; López Jiménez, PA.; Torres Toro, D.; Cobacho Jordán, R. (2020). A Front-Line and Cost-Effective Model for the Assessment of Service Life of Network Pipes. Water. 12(3):1-23. https://doi.org/10.3390/w12030667S123123Shamir, U., & Howard, C. D. D. (1979). An Analytic Approach to Scheduling Pipe Replacement. Journal - American Water Works Association, 71(5), 248-258. doi:10.1002/j.1551-8833.1979.tb04345.xKleiner, Y., Nafi, A., & Rajani, B. (2010). Planning renewal of water mains while considering deterioration, economies of scale and adjacent infrastructure. Water Supply, 10(6), 897-906. doi:10.2166/ws.2010.571Christodoulou, S., & Deligianni, A. (2009). A Neurofuzzy Decision Framework for the Management of Water Distribution Networks. Water Resources Management, 24(1), 139-156. doi:10.1007/s11269-009-9441-2Kutyłowska, M. (2015). Neural network approach for failure rate prediction. Engineering Failure Analysis, 47, 41-48. doi:10.1016/j.engfailanal.2014.10.007Motiee, H., & Ghasemnejad, S. (2018). Prediction of pipe failure rate in Tehran water distribution networks by applying regression models. Water Supply, 19(3), 695-702. doi:10.2166/ws.2018.137Di Nardo, A., Di Natale, M., Giudicianni, C., Greco, R., & Santonastaso, G. F. (2017). Complex network and fractal theory for the assessment of water distribution network resilience to pipe failures. Water Supply, 18(3), 767-777. doi:10.2166/ws.2017.124Kutyłowska, M. (2018). Forecasting failure rate of water pipes. Water Supply, 19(1), 264-273. doi:10.2166/ws.2018.078Le Gat, Y., & Eisenbeis, P. (2000). Using maintenance records to forecast failures in water networks. Urban Water, 2(3), 173-181. doi:10.1016/s1462-0758(00)00057-1Alvisi, S., & Franchini, M. (2010). Comparative analysis of two probabilistic pipe breakage models applied to a real water distribution system. Civil Engineering and Environmental Systems, 27(1), 1-22. doi:10.1080/10286600802224064Kimutai, E., Betrie, G., Brander, R., Sadiq, R., & Tesfamariam, S. (2015). Comparison of Statistical Models for Predicting Pipe Failures: Illustrative Example with the City of Calgary Water Main Failure. Journal of Pipeline Systems Engineering and Practice, 6(4), 04015005. doi:10.1061/(asce)ps.1949-1204.0000196Santos, P., Amado, C., Coelho, S. T., & Leitão, J. P. (2016). Stochastic data mining tools for pipe blockage failure prediction. Urban Water Journal, 14(4), 343-353. doi:10.1080/1573062x.2016.1148178Debón, A., Carrión, A., Cabrera, E., & Solano, H. (2010). 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Private Water Storage Tanks: Evaluating Their Inefficiencies

[EN] Private water storage tanks are often considered as very inefficient devices than can only be justified in systems that suffer frequent water service interruptions. This paper presents the results obtained after studying four different aspects of this question: the effect of this kind of tanks on water losses, unaccounted for water, time modulation curve and energy losses (other implications, such as those related to water quality deterioration, remain out of the scope of the study). Conclusions for each particular point will turn uneven, specially highlighting the effect on the meter global error and unregistered water. In any case, all four points, as well as several additional issues to be considered, are described and evaluated.Authors would like to thank the essential support of SPANISH MINISTRY OF EDUCATION, through the research project “Ordenación y valoración de estrategias orientadas a la progresiva eliminación de los depósitos de almacenamiento de los usuarios en los abastecimientos de agua urbanos”. CGL2005-03666/HID.Cobacho Jordán, R.; Arregui De La Cruz, F.; Cabrera Marcet, E.; Cabrera Rochera, E. (2008). Private Water Storage Tanks: Evaluating Their Inefficiencies. Water Practice & Technology. 3(1):1-8. https://doi.org/10.2166/wpt.2008.025S183

Graphical method to calculate the optimum replacement period for water meters

Calculating the optimum replacement period of meters has always been a major concern for water utility managers. Its determination is time-consuming and requires multiple calculations. This note presents a graphical method to obtain, in a simple but accurate manner, the optimum replacement period of installed meters. For this purpose, a chart has been produced, in which the most in¿uencing variables are considered. These variables include the degradation rate of the weighted error of the meters, the selling price of water, the acquisition and installation cost of the meters, the volume consumed by the users and the discount rate. The chart also allows for a quick sensitivity analysis of different options. For example, by plotting straight lines it is possible to determine by how much the optimum replacement frequency of a meter would change if it degrades at a different rate than expected or if the selling price of water increases.Spanish Ministry of Science and Innovation, through Project No. CGL2008-01910.Arregui De La Cruz, F.; Cobacho Jordán, R.; Cabrera Rochera, E.; Espert Alemany, VB. (2011). Graphical method to calculate the optimum replacement period for water meters. Journal of Water Resources Planning and Management. 137(1):143-146. https://doi.org/10.1061/(ASCE)WR.1943-5452.0000100S143146137

Simplifying water consumption flow traces for improving end use recognition: a case study

[EN] The success of automatic water end use disaggregation and classification strategies greatly depends on the filtering and signal conditioning of the flow traces recorded. The work presented proposes a new filtering algorithm of water consumption flow traces. To improve the performance of the filter, the parameters driving the process are found per event by an automatically calibration procedure. These parameters are selected to ensure the maximum adaptability and simplification of the filtered flow traces. The methodology has been tested with 5210 consumption events obtained from a measurement campaign conducted in a Spanish city. The results obtained show that the filtering algorithm is capable of significantly simplifying the original flow traces while maintaining their main characteristics. On average, it has been found that the most complex events can be described using only 10% of the input data. This analysis can be used to make more efficient the filtering procedure proposed.[ES] El éxito de estrategias para la desagregación y clasificación automática de los consumos de agua en usos finales depende de un adecuado filtrado previo de las trazas de caudal registradas. Se propone un nuevo algoritmo de filtrado, cuyos parámetros de entrada se ajustan mediante un proceso de calibración automático por evento de consumo, asegurando la adaptabilidad y simplificación de la traza filtrada a la original. Esta herramienta se aplica a un caso de estudio mediante el análisis de 5210 eventos de consumo, procedentes de una campaña de monitorización en una ciudad española. Los resultados muestran que el filtro es capaz de simplificar sustancialmente las trazas de caudal manteniendo la información esencial. En media, las trazas de caudal de eventos más complejos pueden definirse con menos del 10% de los puntos de las trazas originales. Además, el análisis realizado permite identificar diversas estrategias para mejorar y optimizar el proceso de filtrado.El trabajo presentado en este artículo ha sido posible gracias al Proyecto IMPADAPT/CGL2013-48424-C2-1-R del Ministerio de Economía y Competitividad de España con fondos FEDER y al VII Programa Marco de la Unión Europea, bajo el acuerdo de financiación no. 619172(SmartH2O: an ICT Platform to leverage on Social Computing for the efficient management of Water Consumption).Pastor Jabaloyes, L.; Arregui De La Cruz, F.; Cobacho Jordán, R. (2018). Mejora del reconocimiento de usos finales del agua mediante la simplificación de la traza de caudal: un caso de estudio. Ingeniería del Agua. 22(4):195-208. https://doi.org/10.4995/ia.2018.9476SWORD195208224Arregui, F. (2015). New software tool for water End-Uses studies. Presentation of 8th IWA International Conference on Water Efficiency and Performance Assessment of Water Services, Cincinnati, USA.Cominola, A., Giuliani, M., Piga, D., Castelletti, A., Rizzoli, A.E. (2015). Benefits and challenges of using smart meters for advancing residential water demand modeling and management: A review. Environmental Modelling & Software, 72, 198-214, https://doi.org/10.1016/j.envsoft.2015.07.012DeOreo,W.B., Heaney, J.P., Mayer, P.W. (1996). Flow trace analysis to assess water use. American Water Works Association, 88, 79-90. https://doi.org/10.1002/j.1551-8833.1996.tb06487.xFielding, K.S., Spinks, A., Russell, S., McCrea, R., Stewart, R.A., Gardner, J. (2013). An experimental test of voluntary strategies to promote urban water demand management. Journal of Environmental Management, 114, 343-351. https://doi.org/10.1016/j.jenvman.2012.10.027Gupta, H.V., Kling, H., Yilmaz, K.K., Martinez, G.F. (2009). Decomposition of the mean squared error and NSE performance criteria: Implications for improving hydrological modelling. Journal of Hydrology, 377, 80-91,https://doi.org/10.1016/j.jhydrol.2009.08.003Kowalski, M., Marshallsay, D. (2003). A System for Improved Assessment of Domestic Water Use Components. II International Conference Efficient Use and Management of Urban Water Supply, International Water Association, Tenerife, Spain.Larson, E., Froehlich, J., Campbell, T., Haggerty, C., Atlas, L., Fogarty, J., Patel, S.N. (2012). Disaggregated water sensing from a single, pressure-based sensor: An extended analysis of HydroSense using staged experiments. Pervasive and Mobile Computing, 8, 82-102. https://doi.org/10.1016/j.pmcj.2010.08.008Nguyen, K.A., Zhang, H., Stewart, R.A. (2013a). Development of an intelligent model to categorise residential water end use events. Journal of Hydro-environment Research, 7, 182-201. https://doi.org/10.1016/j.jher.2013.02.004Nguyen, K.A., Stewart, R.A., Zhang, H. (2013b). An intelligent pattern recognition model to automate the categorisation of residential water end-use events. Environmental Modelling & Software, 47, 108-127. https://doi.org/10.1016/j.envsoft.2013.05.002Pastor-Jabaloyes, L., Arregui, F.J., Cobacho, R. (2018). Water End Use Disaggregation Based on Soft Computing Techniques. Water, 10(1), 46. https://doi.org/10.3390/w10010046R Core Team (2013). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Disponible en: http://www.R-project.org/.UNEP (United Nations Environment Programme). (2011). Water: Investing in Natural Capital. UNEP, Towards a Green Economy: Pathways to Sustainable Development and Poverty Eradication, Nairobi