Calculation Of Energy Savings Research Articles

Analysis of Energy Performance Indicators Based on ISO 50001-2018 in Shopping Centers Using RETScreen Expert

The ISO 50001 energy management system has been implemented by many organizations around the world, including in Indonesia. The purpose of this application is to sustainably improve energy performance to reduce energy consumption and energy costs. In determining the measurement of energy performance improvement, energy performance indicators and energy baseline are used. This study will analyze the energy performance indicators obtained from the energy audit results of one shopping center in Indonesia using RETScreen Expert software. Multiple linear regression is used to develop the energy baseline equation and examine the relationship between energy consumption and significantly influencing variables, such as Service Usage (person) and Cooling Degree Days (CDD). This baseline equation will be used to monitor energy performance after energy performance improvement measures are taken. From the results of this equation, the predicted value of energy consumption in 2023 after improving energy performance in 2022 is 7,014,081 kWh then from the actual measurement results obtained energy consumption value of 6,113,632 kWh the results of the calculation of energy savings obtained from the energy baseline equation using RETScreen Expert software is 900,449 kWh / year.

Moisture absorption and desorption characteristics and prediction model analysis of building thermal insulation materials

Understanding the isothermal moisture absorption and desorption characteristics of building thermal insulation materials and how they affect thermal conductivity, is curial for accurate building thermal design and energy-saving calculation. In this paper, five types of building thermal insulation materials are selected for investigation. First, the variation trend of the equilibrium mass moisture content of materials in different moisture absorption and desorption stages is studied employing the saturated salt solution method and the constant temperature and humidity box method, and the effect of temperature on the moisture absorption and desorption processes is evaluated. Additionally, the applicable model of the material in the moisture absorption and desorption process is obtained through a fitting analysis of the experimental data. Finally, the influence of the material’s moisture absorption and desorption characteristics on the thermal conductivity is analyzed using the transient thermal conductivity test method. The results highlight that there is a need to consider the moisture absorption and desorption processes to accurately determine the wet material thermal conductivity, and the hysteresis effect of the material in the moisture absorption and desorption processes is directly related to its microstructure and the relative humidity at the initial moisture desorption. At a temperature of 25 oC, the autoclaved aerated concrete exhibits its highest hysteresis rate of thermal conductivity during the moisture desorption process of third stage, reaching 13.2%.

Calculation of the economic and environmental efficiency of introducing advanced technologies in the energy supply of buildings

This article discusses the use of advanced cogeneration technologies at existing combined heat and power plants, regulating the supply of thermal energy in a building using an individual heating point. For Uzbekistan, an urgent problem is the serious study of the use of energysaving technologies, in particular in the heat supply systems, for the efficient use of investments. The achieved effect of reducing specific energy consumption for the production and consumption of thermal energy to the level of world standards will ensure the energy and environmental security of the country, which urgently requires accelerating the implementation of these projects. The search for large and small projects for the technical and technological renewal of production to ensure the competitiveness of products, as well as the means and sources for this should first become the most important task and responsibility of the manager and engineering staff of each heat supply enterprise. The article provides calculations on the basis of which the payback, investment, efficiency of measures in the field of renewable energy sources for electricity and heat supply are determined, as well as the calculation of thermal energy savings when installing an individual heating point.

Restoration of dilapidated pipeline networks using polymer hoses

The paper considers a set of issues affecting the actual problems of operational repair and restoration work on underground pressure water and drainage pipelines made of various materials that have exhausted their standard service life and are subject to numerous defects in the form of cracks, joint divergences, rust growths, fistulas and others. The aim of the work is to consider trenchless technology as a promising method of repairing dilapidated pipelines, which uses the application of polymer hoses to the inner surface of pipeline networks. The general requirements for flexible polymer sleeves and their characteristics, the scope of application of sleeves, as well as requirements for structural materials used in the production of flexible polymer sleeves are considered as the subject of research. The result of the work is an analysis of the sequence and essence of preparatory operations, including in-line diagnostics and a coding system for the results of visual inspection of pipelines. As conclusions, examples of calculating energy savings during water transportation before and after repair and restoration work at an exemplary facility are given, depending on the technical characteristics of the hoses used, as well as their thickness, depending on the depth of the pipeline.

TECHNO-ECONOMIC ANALYSIS OF TRIANGULAR ROOFTOP SOLAR PV MODEL/PLN ON-GRID HOUSEHOLD SCALE IN INDONESIA

The use of solar PV as an alternative to fulfill household-scale electricity needs has begun to be widely developed. However, the problem of investment costs and the location of solar PV placement for household scale is still a challenge in its implementation. The construction model of rooftop solar PV can affect the investment cost and performance of solar PV. In this paper, the triangle model of rooftop solar PV on grid with PLN (PT. Perusahaan Listrik Negara) electricity network is studied in terms of technology and economics to determine the feasibility of implementing 900 VA household-scale power plants. Testing the application of solar PV technology under solar radiation conditions in the city of Surabaya, Indonesia as a case study. Calculation of electricity production, energy savings, energy sales, and energy purchases to determine technological feasibility as well Net Present Value (NPV), Benefit Cost Ratio (BCR), and Payback Period (PP) to determine the level of economic feasibility. The results of the research of 1,5 KWP (kilowatt peak) solar PV technology on a household scale are able to meet energy needs and reduce PLN electricity purchases to 0% and can sell electrical energy by 13.96% / year of the total electrical energy produced. In addition, the NPV, BCR with a value greater than zero, and PP of 8.6 is less than 15 years which is the service life of solar PV, so solar PV/ PLN on grid is feasible to be implemented for household scale power generation models.

Modeling heterothermic fitness landscapes in a marsupial hibernator using changes in body composition.

Hibernation is an adaptive strategy that allows animals to enter a hypometabolic state, conserving energy and enhancing their fitness by surviving harsh environmental conditions. However, addressing the adaptive value of hibernation, at the individual level and in natural populations, has been challenging. Here, we applied a non-invasive technique, body composition analysis by quantitative magnetic resonance (qMR), to calculate energy savings by hibernation in a population of hibernating marsupials (Dromiciops gliroides). Using outdoor enclosures installed in a temperate rainforest, and measuring qMR periodically, we determined the amount of fat and lean mass consumed during a whole hibernation cycle. With this information, we estimated the daily energy expenditure of hibernation (DEEH) at the individual level and related to previous fat accumulation. Using model selection approaches and phenotypic selection analysis, we calculated linear (directional, β), quadratic (stabilizing or disruptive, γ) and correlational (ρ) coefficients for DEEH and fat accumulation. We found significant, negative directional selection for DEEH (βDEEH = - 0.58 ± 0.09), a positive value for fat accumulation (βFAT = 0.34 ± 0.07), and positive correlational selection between both traits (ρDEEH × FAT = 0.24 ± 0.07). Then, individuals maximizing previous fat accumulation and minimizing DEEH were promoted by selection, which is visualized by a bi-variate selection surface estimated by generalized additive models. At the comparative level, results fall within the isometric allometry known for hibernation metabolic rate in mammals. Thus, by a combination of a non-invasive technique for body composition analysis and semi-natural enclosures, we were characterized the heterothermic fitness landscape in a semi-natural population of hibernators.

GUI-Based Data Visualisation Tool for Option C IPMVP using Jupyter Notebook

IPMVP is an acronym for International Performance Measurement and Verification Protocol, used for calculating energy savings by taking some external factors into account to give an equal base for a linear comparison between two periods. However, determining the significant independent variable for routine adjustment causes inconvenient repeated action of regression analysis modeling, which leads to the exhaustive calculation and human error risk. These exasperating actions led to the creation of this project, which aims to provide a user-friendly, insightful, and accurate energy-saving calculation program tool. Thus, the main objective of this project is to develop an energy-saving computational tool for option C IPMVP using web-based data analytic tools to improve efficiency and accuracy in each project. This paper used a web-based mathematical computation, Jupyter Notebook, to determine the significant independent variable for routine adjustment of the adjusted baseline. The program tool was validated using V-model software verification and validation methodology based on IEEE 1012 standards. The study can be concluded that the exhaustive calculation to determine the energy saving based on IPMVP standards can be significantly reduced with precision values at 50%, 80%, 90%, and 95% confidence levels using the proposed program which is equipped with insightful graphs and a user-friendly interface.

Rational Distribution of Taxpayers’ Money Based on a Unified Methodology for Calculating Energy Savings

The article presents the problem of the undetermined methodology for calculating energy savings in production processes, which is the scorecards content of the tender documents of the European Cohesion Policy for the current period until 2027. The consequence of such undetermined approach results in wrong decisions of evaluators and consequently, irrational distribution of taxpayers’ money. Presented methodology is a solution that guides the user step by step and results in data that are comparable with each other. The methodology equalizes the possibilities of including companies from different sectors and prevents the creation of non-expert assessments.

Saving energy via short and shallow torpor bouts

Maintaining a high and stable body temperature as observed in most endothermic mammals and birds is energetically costly and many heterothermic species reduce their metabolic demands during energetic bottlenecks through the use of torpor. With the increasing number of heterotherms revealed in a diversity of habitats, it becomes apparent that triggers and patterns of torpor use are more variable than previously thought. Here, we report the previously overlooked use of, shallow rest-time torpor (body temperature >30 °C) in African lesser bushbabies, Galago moholi. Body core temperature of three adult male bushbabies recorded over five months showed a clear bimodal distribution with an average active modal temperature of 39.2 °C and a resting modal body temperature of 36.7 °C. Shallow torpor was observed in two out of three males (n = 29 torpor bouts) between June and August (austral winter), with body temperatures dropping to an overall minimum of 30.7 °C and calculated energy savings of up to 10%. We suggest that shallow torpor may be an ecologically important, yet mostly overlooked energy-saving strategy employed by heterothermic mammals. Our data emphasise that torpor threshold temperatures need to be used with care if we aim to fully understand the level of physiological plasticity displayed by heterothermic species.

Application of computer vision in optimal design of assembled buildings

The shape data of prefabricated building components are closely related to their safety and reliability. To solve the problem of shape energy-saving optimisation, a radial basis function neural network model based on particle swarm optimisation (PSO) considering temperature compensation is studied and designed, and building information modelling technology is introduced as an auxiliary technology for effective management of visual information, which finally realises the energy-saving calculation of building shape dimensions. The results show that the maximum expansion deformation measured by the proposed model appears at the 28th minute, the maximum expansion deformation is 0.11 mm, the error between the model and the actual value is only 0.02 mm and the difference between the monitoring time points is only 3 min. The total energy consumption values of this model are 36.92, 42.15 and 33.58 kWh/m2 less than those of the PSO model for three types of buildings. In terms of the total contribution rate of energy conservation, the former are 0.76, 0.88 and 2.94% higher than the latter, respectively. Therefore, this research has effectively improved monocular machine vision technology. At the same time, the energy-saving model of shape with temperature compensation for innovative design has also been effectively verified.

Split-degree day method: A novel degree day method for improving building energy performance estimation

Degree days have been widely used in different applications in buildings, such as estimating building energy use and climate classification for building energy standards. However, there are limitations with the use of conventional degree days that result in inaccuracies in estimating building energy consumption using degree day-based methods. This paper proposes a new method, the split-degree day method, that shows substantially improved results in the accuracy of the building energy use estimation compared to the conventional degree day methods. The analysis in 801 locations in the U.S. using regression models showed that the new, proposed split-degree day method in this paper, compared to the conventional degree day method, better accounts for the weather parameters and more accurately estimates end-uses. The split-degree days showed an improvement of over 5% in the accuracy of the total annual energy use prediction, 8% for predicting the heating energy use, 0.3% for predicting the cooling energy use, and 33% for predicting the fan energy use. Additionally, the analysis showed improved results for the model with higher thermal mass and the model with a 24-hour operating schedule. These improvements were due to the fact that the split-degree day method includes more information related to the weather characteristics of a location, which is missing in a conventional degree day calculation procedure that relies on aggregated data at daily intervals. Furthermore, as opposed to the conventional degree days, the accuracy of the estimations using the split-degree days are shown to maintain their high accuracy when the base temperature deviates from the optimal base temperature. The proposed method can be used as a more accurate alternative to the conventional degree days in different applications, including but not limited to building climate classification, building energy estimation, and weather normalization for building energy savings calculation.

Research on Energy-saving Calculation of Navigational Lighting System Powered by Low Current in Green Airport

The airport navigation lighting system is an important energy-consuming system in the flight area. The annual energy consumption of large and medium-sized airports can reach millions of kilowatt hours. At present, the airport is replacing traditional halogen lamps with LED navigation lighting for energy conservation. For LED lighting under the traditional 6.6 A power supply system, the circuit loss is high, and the overall energy-saving effect of the system is not good. A low-current power supply energy-saving navigation lighting system is proposed. The primary cable, secondary cable, isolation transformer, and auxiliary lighting system in the navigation lighting circuit are studied by performing the energy-saving calculation of navigation lights under low currents. By building a set of navigation lighting systems to conduct energy consumption experiments and comparing them with theoretical calculations, a calculation model is proposed to provide a basis for energy-saving calculations for the application of a low-current power supply navigation lighting system.

Solar Energy Use for Premises Heating on Spring and Autumn Periods in Southern Regions of Russia

Improving the energy efficiency of residential and civil construction largely depends on how much fossil fuel we spend on heating, cooling, electric lighting, and other human needs during the operation of the building. The results of calculations of energy savings that can be provided by a passive system of using solar energy for these purposes, which, unlike active systems such as photovoltaic batteries or solar collectors for heating and hot solar water supply, does not require engineering equipment maintenance and is an element of the building itself, is part of its space-planning and a constructive solution. From the point of view of capital expenditures on its device, it is attractive. This is a “solar fireplace” or a Trombe wall – the simplest of all passive systems, the effectiveness of which was used in ancient Rome. The article presents the results of the work carried out by the Department of Architectural and Construction Design and Environmental Physics (ASPiFS) within the framework of master’s and postgraduate works on the rapid justification of the feasibility of using Trombe walls already at the decision-making stage. It is noted that the use of such structures is advisable in the new southern regions of Russia. The dependence of energy savings by such systems depending on the climatic conditions of the construction site is shown.

Engineering resource allocation in artificially minimized cells: Is genome reduction the best strategy?

The elimination of the expression of cellular functions that are not needed in a certain well-defined artificial environment, such as those used in industrial production facilities, has been the goal of many cellular minimization projects. The generation of a minimal cell with reduced burden and less host-function interactions has been pursued as a tool to improve microbial production strains. In this work, we analysed two cellular complexity reduction strategies: genome and proteome reduction. With the aid of an absolute proteomics data set and a genome-scale model of metabolism and protein expression (ME-model), we quantitatively assessed the difference of reducing genome to the correspondence of reducing proteome. We compare the approaches in terms of energy consumption, defined in ATP equivalents. We aim to show what is the best strategy for improving resource allocation in minimized cells. Our results show that genome reduction by length is not proportional to reducing resource use. When we normalize calculated energy savings, we show that strains with the larger calculated proteome reduction show the largest resource use reduction. Furthermore, we propose that reducing highly expressed proteins should be the target as the translation of a gene uses most of the energy. The strategies proposed here should guide cell design when the aim of a project is to reduce the maximum amount or cellular resources.

Janus Interface Engineering Boosting Visibly Transparent Radiative Cooling for Energy Saving.

Visibly transparent radiative cooling (VTRC) shows great potential in energy-saving buildings or car glasses for lighting and cooling. How to balance the lighting and cooling performance is of significance to VTRC. In addition, the thermal radiative performance on the inner side should also be determined for cooling. Here, we designed a Janus VTRC coating consisting of a thermal emitter, PDMS, and a transparent near-infrared reflector, TiO2/Ag/TiO2. On the outer side, the visible transmittance T̅vis = 0.70, while the solar reflectance R̅solar = 0.40, and the thermal emittance in the atmospheric window ε̅LWIR = 0.94 can be achieved experimentally. On the inner side, the thermal emittance ε̅IR can be 0.90 or 0.01 depending on the substrate (glass or near-infrared reflector), which acts as the radiative conductor or barrier for energy saving in hot or cold internal situations. Compared with glass, the designed PDMS/NIR/glass achieves an average temperature drop of 14.6 °C experimentally. The energy-saving calculation based on seven cities in China shows that the VTRC coating can save 34-44% of the annual cooling energy consumption. This Janus visibly transparent radiative cooling technology with internal and external regulation provides a potential strategy for energy saving under the requirement of simultaneous lighting and cooling.

Evaluation of variable speed drives to improve energy efficiency and reduce gas emissions: Case study

Variable speed drives are the most promising technique for reducing electric motors' energy consumption. This paper discusses energy savings by installing variable speed drives to control rotating equipment motors such as pumps, compressors, blowers, and fans in oil processing facilities. In addition to energy savings, variable speed drives will improve overall equipment efficiency, increase reliability, and reduce greenhouse gas (GHG) emissions. An energy audit was performed on a case study to investigate energy consumption for all electric motors. Technical and operational constraints for installing and operating variable speed drives were discussed. Installation requires adjustments in operation schedules and parameters to allow reducing energy consumption. The case study has illustrated how to calculate energy savings for pipelines, air coolers, air blowers for furnaces, pumps with variable flow rates, and reciprocating compressing systems. Variable speed drives were technically and economically accepted in air blowers, fans, and pumps. Energy consumption and GHG emission were reduced by 67%. The payback period for the whole project was less than one year. Meanwhile, it was not valid for reciprocating compressors as the payback period was 6.2 years.

Variant analysis of financial and energy efficiency of the heat recovery system and domestic hot water preparation for a single-family building: The case of Poland

Significant amounts of waste heat are deposited in wastewater, which can be used e.g. for heating domestic water. The aim of the paper was to analyze the efficiency of energy recovery from gray water using a new horizontal heat exchanger in the form of a linear drainage equipped with a wavy middle wall. The experimental research consisted of the analysis of efficiency of the device prototype, and then the calculation of energy savings for the preparation of domestic hot water for 81 test cases. Installations cooperating with an electric and gas water heater were analyzed. A Life Cycle Cost analysis was carried out for the financial effectiveness of a conventional installation and an installation equipped with a heat exchanger for a family of 3. Research have shown that the new heat exchanger reduces energy consumption for hot water preparation by an average of 22–31%. It was established that when using an electric water heater, the investment costs pay back in the period of 4–9 years, and in the case of a gas heater, at least 12 years. The sensitivity analysis showed that an increase in energy prices can significantly shorten the payback period, to 6 years for a gas heater and 2 years for an electric heater. Research has shown that the new heat exchanger can significantly reduce the amount of energy needed to prepare domestic hot water. The research results can be useful for researchers, designers and potential users of heat recovery systems.

Energy Efficiency Policies in Poland and Slovakia in the Context of Individual Well-Being

Improving energy efficiency includes a number of measures implemented as part of the greening of the energy industry, which in turn is a prerequisite for the creation of a sustainable energy industry to ensure energy and environmental security for the world. Despite the adoption of the EU directives on energy efficiency, there is still insufficient public awareness in this area in Poland and Slovakia. This is particularly surprising because improving energy efficiency not only brings national and global benefits, but also has a significant impact on the well-being of individuals and households. The main purpose of the paper is to analyze the national policies of Poland and Slovakia, which are based on the European Directive 2012/27/EU on energy efficiency, and which introduce new measures aimed not only at increasing energy efficiency, but also at increasing the well-being of households and individuals. Methods of desk research and content analysis were used. The current situation in both countries is illustrated by case studies that document the administrative process (Slovakia) and the calculation of energy savings (Poland) when using renewable energy sources in the case of family houses.

Potential of CO2 Emission Reduction via Application of Geothermal Heat Exchanger and Passive Cooling in Residential Sector under Polish Climatic Conditions

The article summarizes the results of the 25-year time horizon performance analysis of the ground source heat pump that serves as a heat source in a detached house in the climatic conditions that prevail in Wrocław, Poland. The main aim is to assess the potential of ground regeneration and reduction of CO2 emission by passive cooling application. The study adds value to similar research conducted worldwide for various conditions. The behavior of the lower source of the heat pump was simulated using EED software. The ground and borehole properties, heat pump characteristics, heating and cooling load, as well as the energy demand for domestic hot water preparation have been used as input data. Based on the brine temperatures for all analyzed cases including the ground with lower and higher values of conductivity and heat capacity, the borehole filler of inferior and superior thermal properties, and the passive cooling option turned on and off, the seasonal efficiencies of the heat pump have been calculated. The energy and emission savings calculations are based on the values obtained. The application of passive cooling reduces the brine temperature drop by 0.5 K to over 1.0 K in consecutive years in the analyzed cases and the thermal imbalance by 65.0% to 65.9%. Electric energy savings for heating and domestic hot water preparation reach 4.5%, but the greatest advantage of the system is the possibility of almost emission-free colling the living spaces which allows reducing around 33.7 GWh of electric energy and 1186–1830 kg of CO2 emission for cooling.

Response Surface Method to Calculate Energy Savings Associated with Thermal Comfort Improvement in Buildings

In developed countries, a large part of the building stock in 2050 will consist of currently existing buildings. Consequently, in order to achieve the objectives in terms of energy efficiency in the building sector we must consider not only new infrastructures but also the old ones. A reduction in energy consumption for climate control of between 50 and 90% can be achieved by rehabilitation and the implementation of different energy efficiency measures. Currently, these measures to reduce energy consumption and associated CO2 emissions can be modelled using computer tools. However, high precision and detail of thermal behaviour models through simulations can mean a great computational cost for companies, which results in a blockage of servers and workers. In this paper, the Response Surface Methodology (RSM) is presented as an innovative methodology for the simplification of models for calculation of the energy savings associated with thermal comfort improvement in buildings. A single-family house model, located in three different climates, is presented as a case study in order to validate the proposed methodology. Different scenarios were simulated, addressing heating and cooling temperature set points and external wall insulation represented by the transmittance (U-value). Results obtained from energy simulation using Design Builder were contrasted against those estimated from the simplified model extracted from the RSM analysis. The results revealed a deviation lower than 3% when comparing both methods. Therefore, the simplified mathematical prediction models are demonstrated to be suitable for the study of the energy performance of buildings, saving computational time, costs and associated human resources.