scholarly journals A Proposal for the Optimisation of Algorithms for the Calculation of the Energy Demands of Residential Housing

Mathematics ◽  
2021 ◽  
Vol 9 (16) ◽  
pp. 1994
Author(s):  
Pamela Hermosilla ◽  
Claudio Quiroz ◽  
Francisco Cabrejos ◽  
Felipe Muñoz-La Rivera

In response to increased energy consumption and CO2 emissions, various energy efficiency policies, standards and housing certifications have emerged around the world. These aim to measure and quantify energy efficiency and endorse homes for meeting certain standards according to consistent categories that vary by continent or country. These energy rating systems correspond to a series of criteria and formulations that, through the calculation and combination of multiple variables, establish the classification values. In Chile, there is the Energy Rating System for Housing (CEV), which performs energy efficiency calculations using dynamic heat balance spreadsheets in Microsoft® Excel. When applied for everyday use and at a large scale, this system has the disadvantage of requiring a great deal of processing time for each simulation. This research proposes an improvement to the CEV energy demand calculation mechanism by generating a solution that takes advantage of the use of multiprocessors and implements the various algorithms in the C programming language. The results show that the CEV values obtained with the proposed calculation engine are equal to those of the current system but demonstrate a 76.5% improvement in their processing time.

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.


2019 ◽  
Vol 15 (6) ◽  
pp. 1985-1998
Author(s):  
Anson Cheung ◽  
Baylor Fox-Kemper ◽  
Timothy Herbert

Abstract. Marine sediments have greatly improved our understanding of the climate system, but their interpretation often assumes that certain climate mechanisms operate consistently over all timescales of interest and that variability at one or a few sample sites is representative of an oceanographic province. In this study, we test these assumptions using modern observations in an idealized manner mimicking paleo-reconstruction to investigate whether sea surface temperature and productivity proxy records in the Southern California Current System can be used to reconstruct Ekman upwelling. The method uses extended empirical orthogonal function (EEOF) analysis of the covariation of alongshore wind stress, chlorophyll, and sea surface temperature as measured by satellites from 2002 to 2009. We find that EEOF1 does not reflect an Ekman upwelling pattern but instead much broader California Current processes. EEOF2 and 3 reflect upwelling patterns, but these patterns are timescale dependent and regional. Thus, the skill of using one site to reconstruct the large-scale dominant patterns is spatially dependent. Lastly, we show that using multiple sites and/or multiple variables generally improves field reconstruction. These results together suggest that caution is needed when attempting to extrapolate mechanisms that may be important on seasonal timescales (e.g., Ekman upwelling) to deeper time but also the advantage of having multiple proxy records.


2020 ◽  
Vol 15 (3) ◽  
pp. 191-199
Author(s):  
Srijana Koirala

Increasing population and rapid development in the planet earth have resulted in increasing demand of energy sources. Developed countries have adopted renewable sources in their policy for a sustainable future but, developing countries like Nepal are still lagging behind. Petroleum gas is used by all the city dwellers which is imported from neighboring countries and is not sustainable for a long term. Rapid urban growth has brought solid waste management and energy demand as a great challenge. Production of energy through biogas can help in management of bio-degradable waste as well as fulfill energy demands. This paper highlights study of large-scale biogas plant in and outside Nepal and explains how they have helped in managing waste, fulfilling energy demands and made positive impact in the community. This paper also suggests on possibilities of biogas as an alternative energy in developing scenario of Nepal.


2020 ◽  
Vol 1 (1) ◽  
pp. 33-47
Author(s):  
Tran Viet Dung

AbstractVietnam has experienced an economic growth accompanied by increasing energy demand and inadequate supplies. Like most developing countries, the increased inefficient use of energy in Vietnam leads to increased greenhouse gas emissions and high energy costs for consumers. Also, the traditional sources of energy are not sufficient to satisfy the demand of the economic sectors.With the negative impact of climate change on water resources and the depletion of coal, oil and gas reserves, Vietnam must diversify and integrate other forms of renewable energies into its energy mix. The efficient use of renewable energy resources can boost economic development. Thus, the policies for endorsing renewable energies and energy efficiency are playing a vital role in ensuring the sustainable development for Vietnam’s future. This paper examines the legal and policy framework influencing the deployment of renewable energies and energy efficiency in Vietnam. The paper also attempts to identify major barriers to a large scale deployment of renewable energies and energy efficiency technologies and offers some possible solutions.


Author(s):  
Diego Da Silva de Souza ◽  
Paulo De Souza Silva ◽  
David Barbosa de Alencar

The general objective of this article was to promote through bibliographic studies the two types of lamps, in addition to the comparative analysis of compact fluorescent lamps versus LED lamps: an economy factor. The specific objectives were: - to explain the conceptual precepts on: lighting engineering, definitions, characteristics, invention, operation, defect, quality and the environments used and the NBRs regulations; - address the economic impact generated by the choice of LED lamps and compact fluorescent lamps; - emphasize on an economic feasibility study on the use of LED lamps and compact fluorescent lamps. The justification of the study is related, in the promotion regarding the use of LED lamps and compact fluorescents, in the factor that generates savings. Since the areas related to artificial lighting are responsible for a significant portion of energy demand, both on a large scale - such as lighting for public roads or industrial buildings - and on smaller scales - in commercial and residential buildings. Therefore, its promotion is crucial in the context of economic viability. The lamps provide the luminous energy, through which a better luminous efficiency is obtained. Currently, there are several types of lamps available, different in several aspects: luminous intensity, reproduction colors, energy efficiency, physical composition, method for emitting light, specific purposes, prices, among others. It is worth mentioning that the lamps differ from each other not only by the different luminous fluxes that they radiate, but also by the different powers they consume. In order to compare them, it is necessary to know how many lumens are generated per absorbed watt. This greatness is called energy efficiency. Thus, the proposal of a study was evidenced, in order to promote these luminous resources, in addition to emphasizing their economic viability.


Author(s):  
Satoshi Gamou ◽  
Koichi Ito ◽  
Ryohei Yokoyama

The relationships between unit numbers and capacities to be installed for microturbine cogeneration systems are analyzed from an economic viewpoint. In analyzing, an optimization approach is adopted. Namely, unit numbers and capacities are determined together with maximum contract demands of utilities such as electricity and natural gas so as to minimize the annual total cost in consideration of annual operational strategies corresponding to seasonal and hourly energy demand requirements. This optimization problem is formulated as a large-scale mixed-integer linear programming one. The suboptimal solution of this problem is obtained efficiently by solving several small-scale subproblems. Through numerical studies carried out on systems installed in hotels by changing the electrical generating/exhaust heat recovery efficiencies, the initial capital cost of the microturbine cogeneration unit and maximum energy demands as parameters, the influence of the parameters on the optimal numbers and capacities of the microturbine cogeneration units is clarified.


2020 ◽  
Vol 10 (11) ◽  
pp. 3979
Author(s):  
Fabiana Silvero ◽  
Fernanda Rodrigues ◽  
Sergio Montelpare

Nowadays, the importance of implementing energy efficiency (EE) measures is growing significantly worldwide, based on its potential to reduce energy demands and mitigate climate change effects. Paraguay is a developing country with the highest per capita hydroelectric energy generation in the world, but only 18% of local consumption is hydroelectric and 41% of its energy matrix corresponds to oil products. This paper aims to analyse the importance the Country places on EE as a strategy towards sustainable development and to highlight as EE is an effective pathway to mitigate the climate changes and contrast their effects. The authors initially provide an insight into the climate scenarios for Paraguay and underline the effects of the climate changes on the buildings’ comfort. Subsequently, the authors provide, by resourcing a bibliographic review, a description of the Paraguayan sectors of greater energy consumption, its policies and targets set for increasing EE. Besides, the main EE projects developed by other neighbouring South American countries are analysed to show the level of development of each one in the scope of EE and to offer a reference basis of potential virtuous solutions to be adopted in Paraguay. A focus on the building sector is also made to provide a foundation for policy analyses to enhance EE in this sector. As a result of this review, evidence that EE is beginning to take part in Paraguay’s public policies was found, with the leaders becoming aware of its importance. Nevertheless, many concrete results could not be achieved as of yet and overcoming these barriers still involve a great challenge. Regarding the building sector, few advances have been noticed regarding the regulations of buildings’ thermal performance, a reason for which the National objectives set need to be more specific to achieve greater collective awareness to enforce them. Finally, key actions are recommended for Paraguay aiming to improve EE levels to face the climate change phenomenon.


2007 ◽  
Vol 362 (1487) ◽  
pp. 2061-2078 ◽  
Author(s):  
Brad A Seibel ◽  
Jeffrey C Drazen

The rates of metabolism in animals vary tremendously throughout the biosphere. The origins of this variation are a matter of active debate with some scientists highlighting the importance of anatomical or environmental constraints, while others emphasize the diversity of ecological roles that organisms play and the associated energy demands. Here, we analyse metabolic rates in diverse marine taxa, with special emphasis on patterns of metabolic rate across a depth gradient, in an effort to understand the extent and underlying causes of variation. The conclusion from this analysis is that low rates of metabolism, in the deep sea and elsewhere, do not result from resource (e.g. food or oxygen) limitation or from temperature or pressure constraint. While metabolic rates do decline strongly with depth in several important animal groups, for others metabolism in abyssal species proceeds as fast as in ecologically similar shallow-water species at equivalent temperatures. Rather, high metabolic demand follows strong selection for locomotory capacity among visual predators inhabiting well-lit oceanic waters. Relaxation of this selection where visual predation is limited provides an opportunity for reduced energy expenditure. Large-scale metabolic variation in the ocean results from interspecific differences in ecological energy demand.


2021 ◽  
Author(s):  
Christopher Xavier Mendieta

Bottom-up engineering models are an emerging approach for evaluating energy efficiency solutions at district or regional scales. More flexible than statistical models, bottom-up models allow planners to quantitatively evaluate energy efficiency and supply options, leading to more effective policies and energy demand solutions that better reflect our changing climate. This thesis compares two bottom-up methods for exploring resource and emission reduction strategies in the institutional sector: the Wireframe method and the Reference method. These methods are compared by predicting the annual consumption of post-secondary student residences in Southern Ontario and measuring the error of each, compared with the 2013 mandatory energy report data from the Ministry of Energy of Ontario. Both methods produced aggregate energy error ranges of 5% to 12% in a detailed analysis, suggesting that they are both effective for large-scale energy reduction studies.


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