Saving energy from urban water demand management

This is the peer reviewed version of the following article: Escrivà Bou, Àlvar, Lund, JR., Pulido-Velazquez, M.. (2018). Saving energy from urban water demand management.Water Resources Research, 54, 7, 4265-4276. DOI: 10.1029/2017WR021448, which has been published in final form at http://doi.org/10.1029/2017WR021448. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] Water use directly causes a significant amount of energy use in cities. In this paper we assessed energy and carbon dioxide emissions related to each part of the urban water cycle and the consequences of some water demand management policies in terms of water, energy, and CO2 emissions in urban water users, water and energy utilities, and the environment. First, we developed an hourly model of urban water uses by customer category, including water-related energy consumption. Next, using real data from the East Bay Municipal Utility District in California, we calibrated a model of the energy used in water supply, treatment, pumping, and wastewater treatment by the utility, obtaining also energy costs. Then, using data from the California Independent System Operator, we obtained hourly costs of energy generation and transport to the point of use for the energy utility. Finally, using average emission factors reported by energy utilities, we estimated greenhouse gas emissions for the entire urban water cycle. Results for East Bay Municipal Utility District show that water end uses account for almost 95% of all water-related energy use; however, the remaining 5% of energy used by the utility still costs over USD12 million annually. The carbon footprint of the urban water cycle is 372 kg CO2/person/year, representing approximately 4% of the total per capita emissions in California. Several simulations analyze the consequences of different water demand management policies, resulting in significant economic impacts for water and energy utilities and environmental benefits by reducing CO2 emissions.This paper has been developed as a result of a mobility stay funded by the Erasmus Mundus Programme of the European Commission under the Transatlantic Partnership for Excellence in Engineering-TEE Project. This research was also partially supported by the IMPADAPT project (CGL2013-48424-C2-1-R and CGL2013-48424-C2-2-R) of the National Research Plan (Plan Estatal I+D+I 2013-2016), funded by the Spanish Ministry MINECO (Ministerio de Economia y Competitividad) and European Federation funds. Water and energy microdata were kindly provided by Frank Loge and Edward Spang, at the Center for Water and Energy Efficiency of the University of California, Davis, who are able to release the data under private agreements and to whom we are very grateful. The results can be totally reproduced using the summary tables included in the supporting information.cEscrivà Bou, À.; Lund, J.; Pulido-Velazquez, M. (2018). Saving energy from urban water demand management. Water Resources Research. 54(7):4265-4276. https://doi.org/10.1029/2017WR021448S4265427654

Modeling residential water and related energy, carbon footprint and costs in California

Starting from single-family household water end-use data, this study develops an end-use model for water-use and related energy and carbon footprint using probability distributions for parameters affecting water consumption in 10 local water utilities in California. Monte Carlo simulations are used to develop a large representative sample of households to describe variability in use, with water bills for each house for different utility rate structures. The water-related energy consumption for each household realization was obtained using an energy model based on the different water end-uses, assuming probability distributions for hot-water-use for each appliance and water heater characteristics. Spatial variability is incorporated to account for average air and household water inlet temperatures and price structures for each utility. Water-related energy costs are calculated using averaged energy price for each location. CO2 emissions were derived from energy use using emission factors. Overall simulation runs assess the impact of several common conservation strategies on household water and energy use. Results show that single-family water-related CO2 emissions are 2% of overall per capita emissions, and that managing water and energy jointly can significantly reduce state greenhouse gas emissions. (C) 2015 Elsevier Ltd. All rights reserved.This paper has been developed as a result of a mobility stay funded by the Erasmus Mundus Programme of the European Commission under the Transatlantic Partnership for Excellence in Engineering-TEE Project. The study has been partially supported by the Plan Nacional I+D+I 2008-2011 (Ministry of Science and Innovation, Spain), projects CGL2009-13238-C02-01 and CGL2009-13238-C02-02.Escrivà Bou, À.; Lund, J.; Pulido-Velazquez, M. (2015). Modeling residential water and related energy, carbon footprint and costs in California. Environmental Science and Policy. 50:270-281. https://doi.org/10.1016/j.envsci.2015.03.005S2702815

Atmospheric extinction coefficients in the Ic\mathrm{I_c} band for several major international observatories: Results from the BiSON telescopes, 1984 to 2016

Over 30 years of solar data have been acquired by the Birmingham Solar Oscillations Network (BiSON), an international network of telescopes used to study oscillations of the Sun. Five of the six BiSON telescopes are located at major observatories. The observational sites are, in order of increasing longitude: Mount Wilson (Hale) Observatory (MWO), California, USA; Las Campanas Observatory (LCO), Chile; Observatorio del Teide, Iza\~{n}a, Tenerife, Canary Islands; the South African Astronomical Observatory (SAAO), Sutherland, South Africa; Carnarvon, Western Australia; and the Paul Wild Observatory, Narrabri, New South Wales, Australia. The BiSON data may be used to measure atmospheric extinction coefficients in the $\mathrm{I_c}$ band (approximately 700-900 nm), and presented here are the derived atmospheric extinction coefficients from each site over the years 1984 to 2016.Comment: 15 pages, 10 figures, 4 tables. Accepted by Astronomical Journal: 2017 July 2

Developing a water-energy-GHG emissions modeling framework: Insights from an application to California's water system

[EN] Integrating processes of water and energy interdependence in water systems can improve the understanding of the tradeoffs between water and energy in management and policy. This study presents a development of an integrated water resources management model that includes water-related energy use and GHG emissions. We apply the model to a simplified representation of California's water system. Accounting for water demands from cities, agriculture, environment and the energy sector, and combining a surface water management model with a simple groundwater model, the model optimizes water use across sectors during shortages from an economic perspective, calculating the associated energy use and electricity generation for each water demand. The results of California's water system show that urban end-uses account for most GHG emissions of the entire water cycle, but large water conveyance produces significant peaks over the summer season. Different policy scenarios show the significant tradeoffs between water, energy, and GHG emissions.Escrivà Bou, À.; Lund, J.; Pulido-Velazquez, M.; Hui, R.; Medellín-Azuara, J. (2018). Developing a water-energy-GHG emissions modeling framework: Insights from an application to California's water system. Environmental Modelling & Software. 109:54-65. doi:10.1016/j.envsoft.2018.07.011S546510

An investigation of angular stiffness and damping coefficients of an axial spline coupling in high-speed rotating machinery

This paper provided an opportunity to quantify the angular stiffness and equivalent viscous damping coefficients of an axial spline coupling used in high-speed turbomachinery. A unique test methodology and data reduction procedures were developed. The bending moments and angular deflections transmitted across an axial spline coupling were measured while a nonrotating shaft was excited by an external shaker. A rotor dynamics computer program was used to simulate the test conditions and to correlate the angular stiffness and damping coefficients. In addition, sensitivity analyses were performed to show that the accuracy of the dynamic coefficients do not rely on the accuracy of the data reduction procedures

Meaning-focused and Quantum-inspired Information Retrieval

In recent years, quantum-based methods have promisingly integrated the traditional procedures in information retrieval (IR) and natural language processing (NLP). Inspired by our research on the identification and application of quantum structures in cognition, more specifically our work on the representation of concepts and their combinations, we put forward a 'quantum meaning based' framework for structured query retrieval in text corpora and standardized testing corpora. This scheme for IR rests on considering as basic notions, (i) 'entities of meaning', e.g., concepts and their combinations and (ii) traces of such entities of meaning, which is how documents are considered in this approach. The meaning content of these 'entities of meaning' is reconstructed by solving an 'inverse problem' in the quantum formalism, consisting of reconstructing the full states of the entities of meaning from their collapsed states identified as traces in relevant documents. The advantages with respect to traditional approaches, such as Latent Semantic Analysis (LSA), are discussed by means of concrete examples.Comment: 11 page