Level Of Energy Efficiency Research Articles

Towards the Necessary Decarbonization of Historic Buildings: A Review

The critical and urgent issue of decarbonization by 2050 needs to include the existing historical built environment in the process of energy requalification. These buildings, subjected to heritage preservation, are extremely inadequate to the modern standards of energy efficiency and thermal comfort, and they exhibit the poorest energy performance. In this study, a review of the existing scientific literature on the matter of energy renovation processes applied to historic buildings is provided. The reviewed papers, selected from scientific databases, were initially categorized according to their reference scale—either individual buildings or urban contexts. Subsequently, the papers were grouped on the basis of the main energy efficiency levels they investigated. The goal is to offer a comprehensive overview of the materials, technologies and strategies currently in use, as well as future perspectives, to aid the ecological transition and foster sustainable development, all while preserving the artistic, cultural and architectural heritage of these buildings.

The technological advancement environmental regulations and their impact on energy efficiency and CO2 emissions

Environmental rules and regulations are essential instruments the government administration uses to control environmental problems in this era of advanced technologies and smooth economic growth. This paper aims to examine how environmental regulations, both mandatory and incentive-based, impact on carbon dioxide (CO2) emissions in the presence of urbanization, foreign trade, economic growth and energy efficiency (EE) in logistics transportation. The influence of explicating factors on dependent variables, such as the highest, lowest, and mean, is estimated using the quantile regression model. We applied a number of econometric techniques like unit root test, panel co-integration, quantiles regression (CO2), quantiles regression (Energy efficiency), endogeneity test, and finally, we applied the robustness test to verify the results. This research uses quantile regression to estimate the influence of environmental regulations on releasing carbon dioxide and energy efficiency, using panel data of China’s thirty provinces from 2005 to 2019. Environmental policies in the Ningxia, Qinghai, and Hainan provinces impose higher pollution penalties, which significantly impact reducing CO2 emissions. These regions release more environmental regulations, and in the provinces that fall between the 25th and 50th percentiles, mandatory environmental regulations significantly lower CO2 emissions. Incentive environmental regulations regarding the environment have a more significant effect on energy efficiency in the 50th–75th, 75th–90th, and higher 90th percentile groups since these groups have made more significant investments in research and development. Meanwhile, the Yunnan, Heilongjiang, and Xinjiang provinces have higher energy efficiency levels due to mandatory environmental legislation. The results provide the correct information to the government to implement effective environmental regulations to achieve sustainable development goals.

Historical Analysis of Real Energy Consumption and Indoor Conditions in Single-Family Passive Building

The paper includes a historical analysis of real energy consumption and indoor conditions in a single-family passive building located in Warsaw, Poland. Passive houses have emerged as a sustainable alternative to the conventional construction of houses, having advantages such as low energy consumption, comfortable indoor temperatures, an environmentally friendly nature, and low carbon emissions. This research consists of indoor temperature assessments over a 5-year period (2018–2022) which include comfort assessments made in accordance with the standard EN 16798-1 and precise assessments made for extreme weather events over a two-week critical period including the heating and cooling seasons. The real energy consumption analysis, including electric heating, outdoor lighting, indoor lighting, ventilation, and domestic hot water, was compared against passive house and nearly-zero energy standards. The results of the study show that the building is thermally comfortable to live in, as it remained mainly in the first comfort category, IEQ I. There was no such issue as overheating and underheating even during extreme weather events. The energy need for heating remained very close to the passive standard, namely 15 kWh/(m2·year). The total primary energy consumption for heating, hot water, and electricity meets the standard required value of 120 kWh/(m2·year). These findings demonstrate the effectiveness of passive house design principles at achieving high levels of thermal comfort and energy efficiency in cold climates. In addition, it is demonstrated that it is possible to maintain comfortable indoor temperatures (even with outdoor air temperatures reaching 35 °C) without air conditioning or cooling systems. The integration of a photovoltaic system offers a viable pathway toward transforming the building into a zero-energy standard, contributing to sustainability goals and reducing carbon emissions.

Research progress in the application of infrared blanching in fruit and vegetable drying process.

Fruits and vegetables offer substantial nutritional and health benefits, but their short shelf life necessitates effective preservation methods. Conventional drying techniques, while efficient, often lead to deterioration in food quality. Recent advancements highlight the potential of infrared blanching (IRB) as a preparatory process to improve drying outcomes. This review systematically evaluated the application of IRB for various fruits and vegetables, including tomatoes, potatoes, carrots, mangoes, apples, peaches, strawberries, grapes, and green beans. IRB demonstrated notable improvements in texture, color retention, and nutrient preservation in dried products. Key operational parameters for effective IRB include product thickness (2-5cm), treatment duration (30s to several minutes), and the distance from the infrared (IR) emitter (10-30cm). These factors collectively ensure efficient heat penetration and energy transfer. Regarding IR generators, far-IR heaters are advantageous due to their uniform heating capabilities, whereas near-IR heaters deliver rapid heating. Catalytic IR generators are also emerging as promising options for industrial-scale applications. This review further explores the principles and mechanisms of IRB, particularly its impact on drying kinetics and the retention of vitamins, antioxidants, and bioactive compounds. Evidence indicates that IRB can reduce drying times by up to 50%, increase drying rates, and lower energy consumption by approximately 17%, achieving energy efficiency levels of 80%-90%. However, limitations such as the shallow penetration depth of IR radiation remain challenging. Potential solutions, such as the development of hybrid blanching methods, are discussed to optimize the drying process further and enhance the quality of dried fruits and vegetables.

The relevance of the issue of increasing the energy efficiency of the electricity conversion process in the current conditions of operation of the electricity distribution networks of Ukraine

The work sets out the basic conditions for the functioning of Ukrainian electric networks, including: the need to comply with the requirements of European integration; functioning in conditions of a deficit in generating capacity and market relations; changing the nature of electricity consumption; wear and tear of electric network equipment. The tasks that are associated with the conditions for functioning and require solutions for the reliable functioning of electric networks and further activities of Ukraine as a member of the European Union are indicated. The main tasks set out in the work include: improving the reliability of electricity supply; the need to increase the level of informatization, automation and energy efficiency. It is noted that on the way to solving the set tasks, the implementation of work on the reconstruction of electric networks is carried out, the basis for financing which is investment programs. The issue of improving the energy efficiency of the process of transforming electric energy under the current conditions of the functioning of the Ukrainian electric networks is revealed and analyzed. Based on the results of the analysis, it is established that the issue of improving the energy efficiency of the process of transforming electric energy is relevant at the time of reconstructing electric networks. It is indicated that the analysis of the energy efficiency of transforming electric energy can be carried out on the basis of a technical and economic model of the costs of transforming electric energy and the parameters that affect the size of the costs. It is noted that in the case of presenting the parameters included in the technical and economic models of costs for the transformation of electrical energy in the form of separate components, a competing effect is observed between the components. It is noted that the advisability of the formulation of general calculation methods for calculating the economic component during the review of the nominal power of transformers.

Improving Productivity at a Marble Processing Plant Through Energy and Exergy Analysis

A marble processing plant (MPP) can achieve sustainable development by implementing energy-saving and consumption-reduction technology. Reducing energy loss in such an energy-intensive plant is crucial for overall energy savings. This study establishes an MPP optimization model based on the second law of thermodynamics and the law of conservation of mass. Marble is an aesthetically pleasing and long-lasting building material that has boosted economies in European and sub-Saharan African nations. However, high energy costs and scarcity have constrained the industry’s economic potential and hindered the achievement of optimal levels of production. The second law of thermodynamics is adopted to study the irreversibilities, inefficiencies, and exergetic performance of a marble processing plant. The Aspen Plus commercial software application is used to model and generate thermodynamic data, determine energy flow streams and conduct sensitivity and optimization analysis to improve data quality and energetic performance outcomes. From the results, the various scales of the exergetic destruction, efficiencies, and exergetic losses are determined, and recommendations are established. The overall energy and exergy efficiency levels were determined to be 87.43% and 86.84%, respectively, with a total exergetic destruction of 200.61 kW. The reported methodologies, cutting-edge ideas, and solutions will give industrialists and other significant stakeholders in the global manufacturing sector cutting-edge information about energy usage and ways to cut energy losses in both new and existing factory designs, manage energy cost components, and adjust energy efficiency to maximize productivity.

Technical solutions and technologies for energy-efficient overhaul of apartment buildings

The study presents a comparative analysis of technical solutions and technologies for energy-efficient capital repairs of apartment buildings. The purpose of the study is to identify technical solutions and technologies during the overhaul of structural elements of an apartment building that ensure the most effective reduction of heat losses and consumption. The methodological approaches of the study are based on a statistical analysis of the data on the results of major repairs in the Russian Federation. According to the results of the study, it was found that when planning major repairs, it is necessary to choose a set of technical solutions and technologies that together contribute to reducing energy consumption during work and achieving the most significant results in increasing the energy efficiency class of a residential building based on a comparative assessment of alternative options. The analysis showed that with the introduction of modern energy-saving technologies, the overhaul of apartment buildings can increase the level of energy efficiency for a minimum period of operation (for a quarter of a century) before the next major overhaul, ensuring equal conditions of energy comfort with new generation buildings (modern construction), which as a result improves the quality of life of citizens and accelerates the economic growth of the country.

Fuzzy logic application in the evaluation of energy efficiency in buildings in Brazil

Energy is a resource that has become indispensable to contemporary life, as it is present in everyday life in all areas. However, this important resource is limited, and during its production, it has great potential to generate socio-environmental problems. Since buildings are one of the main energy consumers, using energy efficiency to soften consumption is essential. To this end, Brazil has the Technical Quality Regulation for the Energy Efficiency Level of Commercial, Service and Public Buildings (RTQ-C), developed by the National Electricity Conservation Program (PROCEL), which grants the evaluation of energy efficiency in buildings. Nevertheless, the RTQ-C includes only five levels of classification and does not consider the uncertainties associated with the analysis parameters. To broaden this assessment, fuzzy logic is an option that provides the determination of sub-levels and more scope for the classification. Thus, the present work aims to propose a fuzzy logic-based model that can assess the energy efficiency of buildings deriving from the RTQ-C parameters. A case study is used to show the applicability and functionality of the proposed model. Using the methodology provided by the RTQ-C manual and by fuzzy logic, it was possible to arrive at a rule base, which provides a more realistic perspective on the energy assessment of a building. The results showed that fuzzy modeling is feasible and more comprehensive, it can be used in other buildings and research with similar characteristics, as well as by managers of public and private companies that seek to evaluate, manage, and make more accurate decisions regarding the energy efficiency of buildings under their responsibility, bringing economic, social, and environmental benefits.

Asymmetries in energy consumption: Efficiency of public spending across Portuguese municipalities

The efficient allocation of public financial resources to energy consumption in Portuguese municipalities is one of the most discussed topics in public finance, given the growing relevance of sustainability and energy efficiency. The study analyzes how public spending affects energy efficiency through a combination of data analysis and hypotheses testing to assess the relationship between public spending and energy consumption. The methodology includes DEA analysis of the financial data and energy consumption of the municipalities, as well as the definition of hypotheses to determine the possible correlations between investment and efficiency. The results suggest that, in general, municipalities with higher levels of public spending have lower levels of energy efficiency. Meanwhile, municipalities with smaller budgets and fewer resources tend to be more efficient. The DEA analysis of the data suggests that energy efficiency is not directly related to the size and/or economic aptitude of municipalities but rather to their ability to adopt new technologies and more efficient budgetary and financial management practices. The hypotheses tested show varying levels of efficiency in public spending in relation to energy consumption. The study also concludes that public policies should focus on technological innovation and benchmarking to improve energy efficiency. The analysis suggests that collaboration between municipalities and the adoption of best practices are essential to tackle regional disparities and promote energy sustainability. AcknowledgmentsThis article is financed by Instituto Politécnico de Lisboa [Polytechnic Institute of Lisbon].

Data Analysis of the Situation of the Residential Sector in Extremadura and Its Energy Classification

This study explores sustainable practices in energy resource management, with the aim of optimizing energy consumption while maintaining quality of life. It focuses on energy efficiency in the residential sector of the autonomous community of Extremadura. The methodology involved collecting data from 50 households, using a computer tool to assess and classify energy efficiency levels. The results showed that homes built before 1994 had low energy ratings, whereas those built afterward demonstrated improvement, reflecting a growing environmental awareness. It was found that small investments, such as the installation of control devices and the adoption of conscious consumption habits, can significantly improve energy efficiency. The study highlights the importance of raising community awareness about energy efficiency and notes that, despite limitations in the data, the findings provide valuable insights for future interventions. In conclusion, energy efficiency is key to a sustainable future, and we all share the responsibility of improving it.

Determination of converter parameters for high-voltage electromechanical systems of stationary installations of industrial fans

Purpose. To study the electromagnetic processes in the circuit of the phase rotor of a high-voltage induction motor connected to the network through a step-up converter, to determine the parameters of the converter and their relationship with the voltage gain to ensure the optimal level of energy efficiency of the electromechanical system. Methodology. Methods of theoretical electrical engineering for the construction of a rotor circuit replacement scheme for an induction motor with a step-up converter, methods for solving a system of first-order differential equations, analytical methods. Findings. The expediency of using a converter that combines the rotor circuit of a high-voltage induction motor with the power supply network and provides regulation of the rotor EMF with the recovery of the slip energy of the induction motor rotor to the power supply network has been proved. This will ensure speed control of powerful high-voltage induction motors on the rotor side with an EMF of up to 600 V and significantly reduce the cost of a high-voltage electromechanical system. A methodology for determining the converter gain and the parameters of the rotor circuit of the electromechanical system is proposed, which allows determining the transformation ratio of the matching transformer at the optimal value of the voltage gain. The conditions of trouble-free operation of the inverter at the moment of start-up of the electromechanical system are determined. Achieving these conditions is ensured by determining the delay of the control signal to the power keys of the inverter of a step-up converter. The correlation between the voltage gain and the equivalent resistance of the rotor circuit of the electromechanical system is established. Originality. The ratio of the voltage gain to the equivalent resistance of the rotor circuit of the electromechanical system is established, which will ensure the matching of the rotor EMF with the voltage of the power supply network while maintaining a high level of energy efficiency. Practical value. A methodology for determining the gain and parameters of a step-up converter is proposed, which allows determining the transformation ratio of a matching transformer at the optimal value of the voltage gain. The proposed methodology can be applied to the modelling of complex powerful high-voltage electromechanical systems, especially for stationary installations of industrial fans.

An investigation of the impact of energy performance certificate (EPC) ratings on residential property prices in Oxfordshire: a hedonic study

ABSTRACT This paper investigates whether energy performance ratings measured by Energy Efficiency Certificates (EPCs) affect the sales prices of residential properties in Oxfordshire, UK. The study makes use of 186,913 sales transactions that took place between 1995 and 2023. Using a hedonic regression estimation, a nonlinear pattern between energy efficiency levels and the sales prices of dwellings, are observed. The results also show that there is evidence of a significant positive relationship between EPC ratings and detached, semi-detached, terraced houses and flats. In the second part of this study, we examine the effects of age, county and type of dwelling on price premiums. To the best of the authors’ knowledge, this study is the only study, using the most comprehensive literature; and the largest, most up to date available data in analysing the Oxfordshire real-estate market, in terms of energy efficiency and price premiums.

Development and validation of the motivation for electricity saving behaviour scale (MESBS) among residents living in energy-efficient buildings in Sweden

Even though energy-efficient technologies are well developed, the behaviour of building occupants plays an important role in the search for the optimum level of energy efficiency. In academic literature, however, very few studies have used psychological theories to understand individuals’ drivers of energy use behaviour when interacting with energy-efficient technologies. Specifically, there are no studies solely focused on individuals' motivations for electricity saving behaviour. This paper is based on an empirical study carried out in energy-efficient residential buildings to develop and test a new scale by applying self-determination theory (SDT). A postal survey about the Motivation for Electricity Saving Behaviour Scale (MESBS), including self-reported electricity use, was sent out to 1,084 residents living in newly built energy-efficient multifamily dwellings and eco-villages in Southern Sweden. The answers obtained from 235 participants were analysed for the reliability and validity of MESBS. The findings indicated that i) MESBS items have good internal consistency and are in line with expectations based on SDT, and ii) the autonomous motivation component of MESBS is strongly associated with electricity saving behaviour (i.e. turning off lights when not needed) in energy-efficient buildings. Our results emphasise the importance of considering individuals’ motivations for undertaking electricity saving behaviour in energy-efficient buildings. The study also provides useful information for future studies of energy-efficient buildings as well as designing new technologies and interventions to reach the optimum level of energy-efficiency.

Canada’s Green Strategy as a Factor in Countering Global Challenges

Canada, like many other countries, is increasingly focusing on transition to a green economy, realizing the problems associated with climate change, carbon emissions and the growing need for energy conservation. Canada is a large country with huge resources and potential for the development of a green economy. The Canadian approach to implementing a green strategy based on clean technologies and best production methods is comprehensively explored. Key government policies and programs to stimulate the development of green sectors of the economy, reduce greenhouse gas emissions and combat climate change are analyzed. The main projects and initiatives aiming to accelerate the transition to renewable energy sources and increase the level of energy efficiency, as well as measures to stimulate environmental consumption among the population and attract foreign investment in the field of green economy, were studied. The role of provinces, territories and municipalities in the development of a green economy are also discussed.

Energy efficiency in middle-income countries with DEA: An approach for Latin America

Latin America and Caribbean countries are focused on meeting their 2030 sustainable development goals, with the promotion of actions that increase energy efficiency being a key pillar. Recent studies have applied various data envelopment analysis (DEA) models to this end, but few include Latin American countries. This study assesses energy efficiency in 18 middle-income Latin American countries from 2008 to 2019 using two super-efficient DEA radial models that are particularly adept at distinguishing between highly efficient units. The analysis incorporates a broader set of countries through clustering techniques to ensure homogeneity. From this analysis, the production function, the technical efficiency, the total energy efficiency factor and their respective correlation coefficients versus the per capita income variable are obtained for each country. Costa Rica and Argentina stand out among the Latin American middle-income countries with the highest energy efficiency within quintile Q1 and Q2, whereas Paraguay and Chile obtain the lowest efficiency within quintile Q5 and Q3. For the 18 countries studied, a higher level of income is not significantly related to a higher level of energy efficiency. This study provides policymakers an alternative indicator for effective monitoring of energy efficiency.

Forecasting Electricity Consumption Using Function Fitting Artificial Neural Networks and Regression Methods

With the growth of smart grids, consumers now have access to new technologies that enable improvements in the quality of service provided and allow new levels of energy efficiency. Much of this increase in energy efficiency is directly related to changes in consumption habits due to the quantity and quality of information made available by new technologies. At this point, short-term consumption forecasting can be considered an effective information tool in the search for better consumption patterns and energy efficiency. This paper presents prediction tests combining the result obtained from an artificial neural network and regression methods. The artificial neural network used was the Multilayer Perceptron (MLP), and its results were compared with polynomial regression techniques (first, second, and third degree), demonstrating the superiority of the network. The neural network has proven to be a highly effective tool for forecasting future data, demonstrating its ability to capture complex patterns in input data and produce accurate estimates. Additionally, the flexibility of neural networks in handling large volumes of data and their continuous adjustment capability further enhance their suitability as a robust tool for future predictions. The results corroborate the capacity of the methodology presented for short-term consumption forecasting.

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The national system of energy saving management in budget sector organizations is presented through the prism of the implementation of targeted directions for increasing the level of energy efficiency by the program-target method, the purpose of which is the concentration of resources of business entities and the construction of a unified energy efficiency management system and the coordination of efforts of both state and regional authorities, local self-government, institutions,etc. An important role is given to the components of the program-target method as a mechanism of state management of a unified system of state and regional authorities and local self-government bodies, institutions, etc., which, in particular, will ensure the coordination of energy components and the formation of an acceptable price for educational services. According to the results of the research, the need for the formation of an energy-efficient policy in each institution of higher education, despite its regional location, based on a comprehensive approach from the standpoint of a single energy space, has been actualized. The author considers the management of energy saving projects of the budget sector organization in relation to their energy security system, i.e. the management system of a budget institution from the standpoint of a single energy space, which provides an effective, reliable and ecologically safe environment, which is minimally affected by internal and external factors of energy saving, and is the guarantor of the quality of services, in particular energy services, provided to the population by public sector facilities. The main factors of energy efficiency of budget sector organizations, the procedure for implementing the energy saving and energy efficiency improvement program, the main factors of managing energy efficient projects in the budget sector, analytical tools for modeling their evaluation system and the stages of developing a scenario of an innovative model of their management are presented. The proposed technologies and tools can be used to build an innovative management model of energy saving projects of budget organizations, in particular, using the pyramid-aggregate modeling method.

Advancements in Piezoelectric‐Enabled Devices for Optical Communication

The ability of piezoelectric materials to convert mechanical energy into electric energy and vice versa has made them desirable in the wide range of applications that oscillate from medicine to the energetics industry. Their implementation in optical communication is often connected with the modulation or other manipulations of the light signals. In this article, the recent advancements in the field of piezoelectrics‐based devices and their promising benefits in optical communication are explored. The application of piezoelectrics‐based devices in optical communication allows dynamic control, modulation, and manipulation of optical signals that lead to a more reliable transmission. It turns out that a combination of artificial‐intelligence‐based algorithms with piezoelectrics can enhance the performance of these devices, including optimization of piezoelectric modulation, adaptive signal processing, control of optical components, and increase the level of energy efficiency. It can enhance signal quality, mitigate interference, and reduce noise‐connected issues. Moreover, this technological fusion can increase the security of optical communication systems. Finally, the potential future research lines are determined.

A preference adjustable capacity configuration optimization method for hydrogen-containing integrated energy system considering dynamic energy efficiency improvement and load fast tracking

The new hydrogen-containing integrated energy system proposed in this paper has complementary coupling of multiple energy forms such as electricity, gas, cold, heat, and hydrogen. For the same type of load demand, equipment with different energy input forms can be dispatched for joint supply. However, different equipment differ in dynamic response speed and energy utilization efficiency, and the reasonable configuration of equipment capacity will directly affect the overall dynamic characteristics and energy efficiency level of the system. Therefore, this paper first proposes an evaluation index that can comprehensively characterize the dynamic energy efficiency and load tracking ability of energy equipment. In addition, a preference adjustable capacity configuration optimization method based on utopian point tracking is proposed with the two optimization objectives of this indicator and the system's equivalent annualized investment cost, and the solution complexity is reduced through segmented linearization of the objective. Simulations presented here show that the capacity configuration optimization method proposed in this paper has a positive effect on improving the dynamic energy efficiency and load tracking ability of the new hydrogen-containing integrated energy system, and can also meet the preference setting needs of different investment entities for capacity configuration optimization goals.

METHODOLOGICAL APPROACH TO ASSESSING THE IMPACT OF ENERGY EFFICIENCY ON THE FINANCIAL PERFORMANCE OF A GAS COMPANY

Currently, the use of energy-saving technologies that reduce costs and improve the production process is the most important factor in the development of the gas industry. The relevance of the research topic is due to the fact that in order to resolve issues related to reducing energy costs in the gas sector of the Russian economy, optimal use of non-renewable energy resources, and reducing technological losses, an integrated approach to assessing energy efficiency is required, as well as a methodology for assessing the impact of energy efficiency indicators on the financial performance of a company. The purpose of this article is to develop a methodological approach to assessing the impact of the level of energy efficiency on the financial performance of a gas company. The research methodology is based on correlation and regression analysis tools. As part of the study, a system of energy efficiency indicators for a gas company's activities has been formed and, using correlation and regression analysis tools, a methodology for assessing the impact of the level of energy efficiency on the financial performance of a gas company is proposed. An algorithm for correlation and regression analysis is presented, which makes it possible to formalize a step-by-step assessment of the impact of the level of energy efficiency on the financial performance of a gas company. The proposed methodological approach allows us to identify correlation-regression dependencies between the company’s key performance indicators (sales revenue and net profit) and the proposed energy efficiency indicators, determine the most significant indicators that affect the company’s performance indicators and determine the equation for the relationship between the company’s performance and energy efficiency indicators. Testing of the proposed approach using the example of the gas company PJSC Gazprom made it possible to quantify how changes in the energy intensity of gas production and the energy intensity of gas transportation will affect changes in sales revenue and net profit of the company. It has been established that the energy efficiency indicator such as the specific energy intensity of gas transportation has the greatest impact on the financial performance of the company. Regression equations have been established to describe the nature of the relationship between energy efficiency indicators and sales revenue and net profit of a gas company.