Influencia de los costes del Agua y la Energía en la renovación de tuberías

En el siglo XX la política del agua en España se han caracterizado por el aumento de la oferta hídrica y por la construcción de nuevas infraestructuras tanto de regulación (presas) como de distribución (redes de tuberías). Sin embargo, en el siglo XXI, el paulatino aumento de la demanda ha originado que satisfacer estas necesidades sea cada vez más y más difícil. El agua es un recurso abundante pero no inagotable. Debido al cambio climático, las sequías son más frecuentes y la utilización del recurso exige mayores niveles de eficiencia. Todo esto ha motivado que, en la actualidad, las políticas del agua se centren en la minimización de los consumos y en la renovación de las infraestructuras existentes. Numerosos estudios han abordado el problema de la renovación de las tuberías de una red de distribución urbana. Éstos se centran en la utilización de nuevos materiales, la determinación precisa del orden de sustitución de las tuberías, la obtención del periodo óptimo de renovación y la minimización de los costes. Esta tesis comienza con una revisión bibliográfica de las necesidades de inversión económica en la renovación de las tuberías, facilita las principales características de los materiales más comúnmente empleados en las redes de distribución y muestra las principales ventajas e inconvenientes, así como el coste, de las nuevas técnicas de rehabilitación y renovación sin zanja. Asimismo, también presenta los últimos trabajos en la obtención de sistemas soporte a la decisión para elegir el orden de renovación de las tuberías. A continuación, se analiza la influencia de los costes del agua y de la energía en la obtención del periodo óptimo de renovación. Para ello, se propone una revisión de la metodología tradicional que incluye por primera vez, además de los costes anteriores, los sociales originados por la ejecución de una renovación y los posibles ahorros que se pueden obtener si la obra se realiza entre varias empresas.Pardo Picazo, MÁ. (2010). Influencia de los costes del Agua y la Energía en la renovación de tuberías [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8426Palanci

Auditoría energética en una red de distribución de agua

La gestión sostenible del agua requiere grandes cantidades de energía que conviene, cuanto menos, evaluar para a partir del análisis efectuado conocer qué acción coste/beneficio es desde esta óptica la que más conviene. Y ello porque sólo de este modo se dará adecuada respuesta a las periódicas crisis de energía que en las últimas décadas se vienen sucediendo. En particular, la última ha aproximado el precio del barril de petróleo a los 150 USA dólares. También la necesidad de reducir las emisiones de gases de efecto invernadero, la única estrategia válida para hacer frente al cambio climático, aconseja reducir tanto cuanto sea posible la factura energética. A partir de la ecuación integral de la energía y de su integración en periodo extendido, se lleva a cabo la auditoría energética de una red de distribución de agua a presión. Se evidencia que la energía entrante es igual a la saliente (la entregada a los usuarios y la perdida en fugas) más la disipada por el rozamiento. Finalmente, a partir de los precedentes términos energéticos, se definen unos indicadores que permiten valorar tanto las características energéticas del sistema como las posibilidades de mejora que permite. La auditoria energética que se presenta exige haber realizado previamente la auditoria hídrica y disponer del modelo matemático y permite cuantificar la relación agua energía en el proceso de distribución del agua. El software utilizado es EPANET 2.0. Abstract: Sustainable management of water requires a huge quantity of energy which, at least, should be quantified in order to evaluate future decisions at the water distribution system. Moreover, it will allow to deal with periodic energy crisis. Last one increased the price of oil up to 150 USA dollars. On the top of that, the requirements to reduce greenhouse effect gases, the key objective to face climatic change, recommends reducing, as much as possible, energy consumption. In this paper, a new methodology to calculate an energy audit in water distribution systems is proposed, from the integral energy equation under extended period simulations. Input energy (pumps, reservoirs) is equal to the consumed by users, leakage and friction losses in the pipes. Finally, some performance indicators are defined to evaluate the energy features of the network and future improvements. Energy audit requires results from a previous water audit of the distribution system that must be properly modelled. Water distribution simulations are performed using the EPAnet 2 simulation software.Pardo Picazo, MÁ. (2008). Auditoría energética en una red de distribución de agua. http://hdl.handle.net/10251/12762Archivo delegad

Sizing and scheduling optimisation method for off-grid battery photovoltaic irrigation networks

An algorithm to optimise the number of solar panels and battery size to meet the water demands of an installation has been developed. The algorithm adjusts for seasonal changes in energy use and production in a pressurized irrigation network and production in an off-grid solar panel system. By using this algorithm, we aim to create an efficient and sustainable irrigation system by reducing the infrastructure and reliance on the power grid. This method can enhance irrigation systems in far-off regions, strengthen their endurance, and promote sustainable energy in farming and water administration.This work was supported by the project “Hi-Edu Carbon”"Erasmus Plus Programme, Key Action KA22021, action type (2021-1-SK01-KA220-HED-000023274

Lifecycle and ecomonical study of selected thermal solar installations

Creating a scheme of solar thermal installations is a mighty move forward to develop a suitable energy standards of residential buildings. In recent years were done many studies, which did a several energy simulations for residence buildings. If design of thermal installation is false, it can lead to rise in the expensive overall energy costs and unsatisfactory thermal comfort in the building. Nowdays, in Slovakia using solar thermal installations are increasing more than in recent years. This research investigates twelve modern solar water heating systems, formed on the roof of the family house. We tried to make analysis, where designed solar energy systems were appropriate and fulfill energy requirements of DHW and heating. The study deals with the best financial alternative of the prepared installations of the house. According to overall prices of installation, energy production of additional source for heating and total system efficiency and lifespan, we found out the best possible choice. Expected amount of the various energy contribution is simulated in specialized program. If we talk about midterm energy values, we can see the best possible choice for the alternatives. In this case we made analysis of these schemes for typical family house in Kosice. We set the limits of the building and analyzed which scheme is the best for need of the yearly average water consumption and heating.This study was financially supported by Grant Agency of Slovak Republic to support project No. 1/0512/20. This paper is also the result of the Project implementation: University Science Park TECHNICOM for Innovation Applications Supported by Knowledge Technology, ITMS: 26220220182, supported by the Research & Development Operational Programme funded by the ERDFI

Economic assessment of converting a pressurised water distribution network into an off-grid system supplied with solar photovoltaic energy

Converting a water pressurised distribution network into an off-grid pumping station supplied by solar photovoltaics represents a challenge for utility managers, user demand assessments evaluate the energy generated in a solar-powered systems to establish energy consumption. This work includes quantifying potential investments and economic savings that could be achieved, as well as the payback period which results as an indicator of the suitability of adapting to a power supply utilising solar panels. A tool (UAsolar) to aid practitioners has been developed, it requires a calibrated hydraulic model to account for the energy requirements in the water delivery process of pressurised networks. The authors encourage students, professionals, and decision-makers to use this tool to identify potential efficiency gains (e.g., delivery schedule, reduction of water use) and to synchronise energy production and consumption. Users can get results with low computational time using the software on six pressurised distribution networks. Practitioners should note that the irrigation networks have sized installations with a few photovoltaic modules, while in urban pressurised networks the results show larger installations are required. In addition, irrigation network managers can match energy demand with energy production by changing consumption over time, this could reduce the quantity of modules required and remove the need for energy storage. The payback period ranges from 6.08 to 13 years for the cases where the investment is recovered—(values that show that this investment yields a high return as the lifetime of the PV modules is 25 years). However, one municipality among those studied shows that in some scenarios it is not viable to convert networks into a standalone system.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Project TEC2017-85244-C2-1-P and by the University of Alicante (vigrob-157, VIGROB-303 and GRE18-15)

Converting a Water Pressurized Network in a Small Town into a Solar Power Water System

The efficient management of water and energy is one challenge for managers of water pressurized systems. In a scheme with high pressure on the environment, solar power appears as an opportunity for nonrenewable energy expenditure reduction and emissions elimination. In Spain, new legislation that eliminates old taxes associated with solar energy production, a drop in the cost of solar photovoltaic modules, and higher values of irradiance has converted solar powered water systems into one of the trendiest topics in the water industry. One alternative to store energy (compulsory in standalone photovoltaic systems) when managing pressurized urban water networks is the use of head tanks (tanks accumulate water during the day and release it at night). This work intends to compare the pressurized network running as a standalone system and a hybrid solution that incorporates solar energy supply and electricity grids. The indicator used for finding the best choice is the net present value for the solar power water system lifespan. This study analyzed the possibility of transferring the energy surplus obtained at midday to the electricity grid, a circumstance introduced in the Spanish legislation since April 2019. We developed a real case study in a small town in the Alicante Province, whose findings provide planning policymakers with very useful information in this case and similar case studies.Antonio Jodar-Abellán acknowledges financial support received from the Spanish FPU scholarship for the training of university teachers. In the same way, this work has been partially funded by the Cátedra del Agua of the University of Alicante and the Diputación Provincial de Alicante (https://catedradelaguaua.org/)

Analysis of Equivalent CO2 Emissions of the Irrigation System—A Case Study

This work aims to assess the emissions related to the useful life of the irrigation network on the campus of the University of Alicante (Spain). A life cycle assessment has been developed employing the One Click LCA software to calculate material proportion, repair rate, energy consumption, water volume, transport, and irrigation surface. This has been used in a real pressurised irrigation network, such as the one at the University of Alicante delivering water to the grass. Two potential cases which consider the pipelines made of polyvinyl chloride (variant 1) and high-density polyethene (variant 2) have also been analysed. Energy consumption had the most influence on emissions discharges (42%), followed by materials (37%) and repairs (18%) in the current water irrigation network. Variant 1 shows higher emissions produced in network materials (47%), energy consumption (27%), and repairs (24%). Variant 2 has high emissions because of energy consumption (47%), materials manufacturing and transport (34%), and repairs (17%). It has been determined that a network of disposed polyethene pipes will reduce the total Global Warming Potential emitted into the atmosphere. Materials (127.9 Tn CO2e) and energy (145.5 Tn CO2e) are the stages where the highest Global Warming Potential is produced. Other stages that also stand out are repairs (62 Tn CO2e), construction (6.3 Tn CO2e), and transport of materials (3.5 Tn CO2e). Renewable energy sources could reduce energy consumption. Variant 2 has 11% lower emissions than the current network (variant 0), making it a workable choice for infrastructure design.This work has been funded by the research project “Hi-Edu Carbon” Erasmus Plus Programme, Key Action KA22021, action type (2021-1-SK01-KA220-HED-000023274)

An algorithm to schedule water delivery in pressurized irrigation networks

This study presents a deterministic constrained optimisation algorithm developed for using in a pressurized irrigation network. In irrigation networks —or water networks supplied by a head tank— utility managers can fully adapt the delivery times to suit their needs. The program provides a strategy for scheduling water delivery at a constant flow rate (opening and closing of hydrants, units, and subunits) to minimise energy consumption. This technique improves on earlier approaches by employing a deterministic method with little computing time. This method has been tested in the University of Alicante pressurized irrigation network, where decision-makers have identified the need to diminish the energy expenditure for watering University’s gardens.This work was supported by the research project “DESENREDA” through the 2021 call “Estancias de movilidad en el extranjero Jose Castillejo” of the Ministerio de Universidades (CAS21/00085) and for the project “Hi-Edu Carbon” Erasmus Plus Programme, Key Action KA22021, action type (2021-1-SK01-KA220-HED-000023274

Pipe replacement by age only, how misleading could it be?

Traditional methods for prioritizing the renewal of water are based on heuristic models, such as the number of breaks per length, rule-of-thumb, and records held by the water utility companies. Efficient management of water distribution networks involves factoring in water and energy losses as the key criteria for planning pipe renewal. Prioritizing the replacement of a pipe according to the highest value of unit headloss due to ageing does not consider the impact on water and energy consumption for the whole network. Thus, this paper proposes a methodology to prioritize pipe replacement according to water and energy savings per monetary unit invested – economic prioritization. This renewal plan shows different results if comparing with replacing pipelines with regard to age and it requires calculating water and energy audits of the water distribution networks. Moreover, the required time to recover the investment performed needs to be calculated. The methodology proposed in this work is compared with the unit headloss criterion used in a real water-pressurized network. The results demonstrate that using the unit headloss criterion neither water, energy nor the investment is optimized. Significant water and energy savings are not fully exploited.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. The translation of this paper has been funded by the Escuela Politécnica Superior, University of Alicante

Optimizing machine learning for agricultural productivity: A novel approach with RScv and remote sensing data over Europe

CONTEXT: Accurate estimating of crop yield is crucial for developing effective global food security strategies which can lead to reduce of hunger and more sustainable development. However, predicting crop yields is a complex task as it requires frequent monitoring of many weather and socio-economic factors over an extended period. Satellite remote sensing products have become a reliable source for climate-based variables. They are easier to obtain and provide detailed spatial and temporal coverage. OBJECTIVE: The aim of this study is to assess the effectiveness of implement a novel optimization algorithm, called Randomized Search cross validation (RScv), on various machine learning algorithms and measure the prediction accuracy enhancement. METHODS: Annual yields of four crops (Barley, Oats, Rye, and Wheat) were predicted across 20 European countries for 20 years (2000–2019). Two NASA missions, namely GPCP and GLDAS satellites, provided us with climate- and soil-based input variables. Those variables were employed as the input of four ensemble Machine Learning (ML) algorithms (Ada-Boost (AB), Gradient Boost (GB), Random Forest (RF) and Extra Tree (ET)) which are faster and more adoptable compare to classic AI algorithms. RESULTS AND CONCLUSIONS: Main results show that applying RScv improves the prediction ability of all ML models over the four crops. In particular, the RScv-AB reaches the overall highest accuracy for predicting yields (R2max = 0.9). Spatial evaluation of predicting errors depicts that the proposed models were more shifted toward underestimation. An uncertainty analysis was also carried out which shows that applying ML algorithms creates higher and lowers uncertainty in Barley and Wheat respectively. SIGNIFICANCE: Considering the robustness of the optimised ML models and the global coverage of remote sensing data, our current methodology demonstrates great transferability and can be applied in other regions across the globe with higher temporal extents. In addition, this tool could be beneficial to decision makers in various sectors to improve the water allocations, deal with climate change effects and keep sustainable agricultural development.Antonio Jodar-Abellan acknowledges financial support received form the Margarita Salas Postdoc Spanish Program