Building performance improvement through low-energy renovation traditionally involves building performance diagnostics of the existing building, technology evaluation, selection and implementation. Effective building performance diagnostics, post-retrofit assessment and user engagement are essential to deliver performance as well as achieving socio-economic and environmental benefits at every stage of the renovation project life cycle. User’s views are often ignored when renovating a building, causing sub-optimal energy performance, user comfort and wellbeing. This paper seeks to critically evaluate the low-energy renovation process and the role of user and stakeholder engagement in the strategic implementation of low-energy retrofit technologies for performance improvement of higher education buildings. The research focuses on renovation methodology, innovative materials/systems and end-user engagement throughout the renovation project phases (pre-renovation, the renovation process an... [more]

In this paper, we examine whether innovation and information and communication technology (ICT) contribute to reducing producer prices, thus promoting economic growth. We also check whether the contributions of ICT enhance environmental quality, leading to sustainable economic growth. To this end, we apply panel data techniques to the 27 EU countries over the period of recovery from the financial crisis. Our results suggest that technological progress leads to a significant reduction in producer prices. Moreover, controlling for some macroeconomics factors, ICT fosters per capita economic growth in the European countries. Finally, we found that the higher the ICT employment is, the lower greenhouse gas emissions are.

Marine microbial communities are an untapped reservoir of genetic and metabolic diversity and a valuable source for the discovery of new natural products of biotechnological interest. The newly discovered hydrothermal vent field of Santorini volcanic complex located in the Aegean Sea is gaining increasing interest for potential biotechnological exploitation. The conditions in these environments, i.e., high temperatures, low pH values and high concentration of heavy metals, often resemble harsh industrial settings. Thus, these environments may serve as pools of enzymes of enhanced catalytic properties that may provide benefits to biotechnology. Here, we screened 11 metagenomic libraries previously constructed from microbial mat samples covering the seafloor and the polymetallic chimneys of Kolumbo volcano as well as mat samples from Santorini caldera, to mine, in silico, genes associated with bioenergy applications. We particularly focused on genes encoding biomass hydrolysis enzymes su... [more]

Cyber−physical systems (CPSs) are an integral part of modern society; thus, enhancing these systems’ reliability and resilience is paramount. Cyber−physical testbeds (CPTs) are a safe way to test and explore the interplay between the cyber and physical domains and to cost-effectively enhance the reliability and resilience of CPSs. Here a review of CPT elements, broken down into physical components (simulators, emulators, and physical hardware), soft components (communication protocols, network timing protocols), and user interfaces (visualization-dashboard design considerations) is presented. Various methods used to validate CPS performance are reviewed and evaluated for potential applications in CPT performance validation. Last, initial simulated results for a CPT design, based on the IEEE 33 bus system, are presented, along with a brief discussion on how model-based testing and fault−injection-based testing (using scaling and ramp-type attacks) may be used to help validate CPT perfor... [more]

Although one of the most harmful factors to health is noise, it is often ignored in life cycle assessment (LCA) studies. Most researches regarding noise inclusion in LCA focus on the problem of transport noise, and very few works consider the impact of noise emitted by other sources. This study addresses the effects of noise generated by cogeneration plants. The main objective is to assess the environmental performance of the noise reduction system by considering the health effects of noise due to steam discharge as well as to compare the environmental loss associated with the production and disposal of a steam silencer with the benefits resulting from its application for noise reduction. A method to determine midpoint and endpoint human health indicators for a composition of noise emitted by intermittent stationary source and background noise is developed. The results indicate that the health benefit due to noise reduction is six orders of magnitude greater than the environmental loss... [more]

This article discusses the problem of minimizing power loss in unbalanced distribution systems through phase-balancing. This problem is represented by a mixed-integer nonlinear-programming mathematical model, which is solved by applying a discretely encoded Vortex Search Algorithm (DVSA). The numerical results of simulations performed in IEEE 8-, 25-, and 37-node test systems demonstrate the applicability of the proposed methodology when compared with the classical Cuh & Beasley genetic algorithm. In addition, the computation times required by the algorithm to find the optimal solution are in the order of seconds, which makes the proposed DVSA a robust, reliable, and efficient tool. All computational implementations have been developed in the MATLAB® programming environment, and all the results have been evaluated in DigSILENT© software to verify the effectiveness and the proposed three-phase unbalanced power-flow method.

The article investigates nature−culture interrelation over the case studies of hydroelectric plants of the 20th century. In many cases, construction of these structures has evidently resulted in irreversible changes in natural and cultural environments. However, they have also supplied energy for the industrialization of civilizations. After approximately 100 years of existence, it is crucial to determine the future of these hydroelectric facilities, which are artifacts of industrial heritage approaching the end of their productive life spans. The article proposes an analytical approach aiming to sustain the integrity of nature and culture in the conservation of hydroelectric plants, presenting these energy facilities as cultural properties of industrial heritage, and discussing the impact of hydroelectric dams on natural and cultural environments, along with the effects of nature in the deterioration of these structures in order to pave the way to an optimized and sustainable future f... [more]

Among the super insulating materials, aerogel has interesting properties: very low thermal conductivity and density, resistance to high temperatures and transparency. It is a rather expensive material, but incentives in the field can improve its economic attractiveness. Starting from this, the thermal behavior of a test building entirely insulated with aerogel panels was investigated through an extended experimental campaign. A dynamic simulation model of a case study building was generated to better comprehend the energy savings obtained through aerogel in terms of energy demand over a whole year. The investigation was completed by computing the carbon and energy payback times of various retrofit strategies through a life cycle assessment approach, as well as by a cost-benefit analysis through a probabilistic financial framework. Compared to conventional insulation materials, aerogel is characterized by a higher energy and carbon payback time, but it guarantees better environmental pe... [more]

Conventional constant speed turbo air centrifugal compressor systems (TACCSs) consist of an electric motor driven at the constant speed and an inlet guide vane (IGV) for pressure control. TACCSs with an inverter for a variable speed drive (VSD) of the electric motor are more efficient than the conventional constant speed TACCS because they have a wide operating range and can minimize the power consumption. Therefore, this paper proposes a quadratic V/f control and VSD to reduce electrical and mechanical energy losses. To verify the energy saving effect of the TACCS with the proposed controls, this paper analyzes the performances of an electric motor drive system (EMDS) using the proposed quadratic V/f control considering load conditions of the turbo air centrifugal compressor (TACC) to reduce electrical energy losses. Furthermore, the performances of the conventional constant speed drive (CSD) using the IGV control and the proposed VSD were compared and analyzed in the test bench that... [more]

This study aims to overview the U.S. sustainable development by measuring the environmental performance of 50 states over the period of 2009−2018. To attain the objective, we employ data envelopment analysis for environmental assessment where we prioritize the minimization of CO2 emissions first and the maximization of gross state product later under the concept of managerial disposability (i.e., an environment-based performance measure). Then, we examine how the state-level environmental performance measures are associated with their political and spatial contexts. For the purpose, we conduct the Kruskal-Wallis rank sum test across groups of states characterized by their political transitions in the presidential and gubernatorial elections and defined by the regions of the U.S. Economic Development Administration and Environmental Protection Agency. Based on our empirical results, we find that (a) overall environmental performance has gradually enhanced over time, (b) there are statis... [more]

Industrial symbiosis networks conventionally provide economic and environmental benefits to participating industries. However, most studies have failed to quantify waste management solutions and identify network connections in addition to methodological variation of assessments. This study provides a comprehensive model to conduct sustainable study of industrial symbiosis, which includes identification of network connections, life cycle assessment of materials, economic assessment, and environmental performance using standard guidelines from the literature. Additionally, a case study of industrial symbiosis network from Sodankylä region of Finland is implemented. Results projected an estimated life cycle cost of €115.20 million. The symbiotic environment would save €6.42 million in waste management cost to the business participants in addition to the projected environmental impact of 0.95 million tonne of CO2, 339.80 tonne of CH4, and 18.20 tonne of N2O. The potential of further cost s... [more]

This study aims to evaluate the economic and environmental efficiency of Asian and African economies. In the model proposed, Gross Domestic Product (GDP) is considered as the desired output and Greenhouse Gases (GHG), like carbon dioxide (CO2) emissions, as the undesirable output. Capital, labor, fossil fuels, and renewable energy consumption are regarded as inputs, and the GDP/CO2 ratio is the output, by using a log-linear Translog production function and using data from 2005 until 2018, including 22 Asian and 22 African countries. Results evidence cross-countries heterogeneity among production inputs, namely labor, capital, and type of energy use and its efficiency. The models complement each other and are based on different distributional assumptions and estimation methods while providing a picture of Eco-efficiency in Asian and African economies. Labor and renewable energy share increase technical Eco-efficiency, while fixed capital decreases it under time-variant models. Technical... [more]

The pulp and paper (P&P) sector is a dynamic manufacturing industry and plays an essential role in the Austrian economy. However, the sector, which consumes about 20 TWh of final energy, is responsible for 7% of Austria’s industrial CO2 emissions. This study, intending to assess the potential for improving energy efficiency and reducing emissions in the Austrian context in the P&P sector, uses a bottom-up approach model. The model is applied to analyze the energy consumption (heat and electricity) and CO2 emissions in the main processes, related to the P&P production from virgin or recycled fibers. Afterward, technological options to reduce energy consumption and fossil CO2 emissions for P&P production are investigated, and various low-carbon technologies are applied to the model. For each of the selected technologies, the potential of emission reduction and energy savings up to 2050 is estimated. Finally, a series of low-carbon technology-based scenarios are developed and evaluated. T... [more]

Nitrogen dioxide (N2O) is a greenhouse gas that is harmful to the ozone layer and contributes to global warming. Many other nitrogen oxide emissions are controlled using the selective non-catalytic reaction (SNCR) process, but N2O reduction methods are few. To avoid future air pollution problems, N2O reduction from industrial sources is essential. In this study, a N2O decomposition and NO formation under an argon atmospheric N2O gas mixture were observed in a lab-scale SNCR system. The reaction rate and mechanism of N2O were calculated using a reaction path analyzer (CHEMKIN-PRO). The residence time of the gas mixture and the temperature in the reactor were set as experimental variables. The results confirmed that most of the N2O was converted to N2 and NO. The change in the N2O reduction rate increased with the residence time at 1013 and 1113 K, but decreased at 1213 K due to the inverse reaction. NO concentration increased with the residence time at 1013 and 1113 K, but decreased at... [more]

Furfural is only derived from lignocellulosic biomass and is an important chemical used in the plastics, agrochemical, and pharmaceutical industries. The existing industrial furfural production process, involving reaction and purification steps, suffers from a low yield and intensive energy use. Hence, major improvements are needed to sustainably upgrade the furfural production process. In this study, the conventional furfural process based on a continuous stirred tank reactor and distillation columns was designed and optimized from an actual aqueous xylose solution via a biomass pretreatment step. Subsequently, a reactive distillation (RD) and extraction/distillation (ED) configuration was proposed for the reaction and purification steps, respectively, to improve the process efficiency. RD can remove furfural instantly from the reactive liquid phase and can separate heavy components from the raw furfural stream, while the ED configuration with toluene and butyl chloride used as extrac... [more]

The prevailing need for a more sustainable management of natural resources depends not only on the decisions made by governments and the will of the population, but also on the knowledge of the role of energy in our society and the relevance of preserving natural resources. In this sense, critical work is being done to instill key concepts—such as the circular economy and sustainable energy—in higher education institutions. In this way, it is expected that future professionals and managers will be aware of the importance of energy optimization, and will learn a series of computational methods that can support the decision-making process. In the context of higher education, this paper reviews the main trends and challenges related to the concepts of circular economy and sustainable energy. Besides, we analyze the role of simulation and serious games as a learning tool for the aforementioned concepts. Finally, the paper provides insights and discusses open research opportunities regardin... [more]

With the increasing demand for clean and low-carbon energy, high proportion of renewable energy has been integrated into the receiving-end grid. The grid-side energy storage project can ensure the safe and stable operation of the grid, but it still faces many problems, such as high initial investment, difficult operation and maintenance, unclear profit model, lack of business mode. Therefore, it is of great significance to evaluate the comprehensive benefit of energy storage projects in order to guide the sustainable development of large-scale energy storage projects and power system. By studying the technical and economic characteristics of energy storage, this paper establishes a comprehensive evaluation system from four dimensions of energy efficiency, economic, social, and environmental benefit. Combined with typical business modes and determining the subdivision index system of different modes, the comprehensive benefit evaluation model of grid-side commercial storage project base... [more]

This study quantifies the technical, economic and environmental performance of hybrid systems that use either a tidal stream or wind turbine, alongside short-term battery storage and back-up oil generators. The systems are designed to partially displace oil generators on the island of Alderney, located in the British Channel Islands. The tidal stream turbine provides four power generation periods per day, every day. This relatively high frequency power cycling limits the use of the oil generators to 1.6 GWh/year. In contrast, low wind resource periods can last for days, forcing the wind hybrid system to rely on the back-up oil generators over long periods, totalling 2.4 GWh/year (50% higher). For this reason the tidal hybrid system spends £0.25 million/year less on fuel by displacing a greater volume of oil, or £6.4 million over a 25 year operating life, assuming a flat cost of oil over this period. The tidal and wind hybrid systems achieve an oil displacement of 78% and 67% respective... [more]

New methods for the use of waste products as input for other technologies are a constant subject of research efforts. One such product is waste engine oil. Due to the constantly increasing number of motor vehicles in the world, the recycling or application of engine oils for energy production purposes is currently of considerable importance. This paper contains research regarding the analysis of the electro-oxidation potential of waste engine oil, and thus the possibility of using such oil as a material in fuel cells. The research demonstrates the basic possibility of the electro-oxidation of this oil emulsion on a platinum electrode in an acid electrolyte (aqueous solution of H2SO4). It was shown that in the temperature range of 20−80 °C, the electro-oxidation of the waste engine oil emulsion occurred for all emulsion concentrations (0.005%, 0.010%, 0.030%, and 0.060% of the reactor volume). The maximum current density obtained in the measurements was 21 mA·cm−2 at the temperature of... [more]

This paper presents a mathematical approach for determining the reliability of solar tracking systems based on three fault coverage-aware metrics which use system error data from hardware, software as well as in-circuit testing (ICT) techniques, to calculate a solar test factor (STF). Using Euler’s named constant, the solar reliability factor (SRF) is computed to define the robustness and availability of modern, high-performance solar tracking systems. The experimental cases which were run in the Mathcad software suite and the Python programming environment show that the fault coverage-aware metrics greatly change the test and reliability factor curve of solar tracking systems, achieving significantly reduced calculation steps and computation time.

Environmental problems such as air pollution and greenhouse gas emissions are caused by almost all transport modes. A potential solution to these problems could be electric mobility. Currently, efforts to increase the use of various types of electric vehicles are under way virtually worldwide. While in recent years a major focus was put on the electrification of passenger cars, electricity has already, for more than hundred years, been successfully used in some public transport modes such as tramways and metros. The core objective of this paper is to analyze the historical developments and the prospects of electric mobility in different transport modes and their potential contribution to the solution of the current environmental problems. With respect to the latter, we analyze the effect of the electricity generation mix on the environmental performance of electric vehicles. In addition, we document major policies implemented to promote various types of e-mobility. Our major conclusion... [more]

Ester liquids are environmentally friendly insulating oils, and they can be used as an alternative to mineral oil in transformers, even though in most countries spills of ester oils must be treated like spills of mineral oil. Furthermore, the breakdown characteristics of ester liquids are worse than those of mineral oils in heterogeneous electric fields. In this paper, we present a comprehensive experimental research on both positive and negative lightning impulse breakdown properties in point-plane geometries with gaps varying from 1 mm to 50 mm. The breakdown voltages and streamer velocities of five kinds of ester liquids, including natural ester, synthetic ester, and three kinds of single component esters have been measured. The results show that the double bonds have no effect on the breakdown voltage of ester liquids. The average streamer velocities of mono-esters are faster than that of other esters under positive polarity, and the breakdown voltages of all esters are close.

The scientific community is active in developing new models and methods to help reach the ambitious target set by UN SDGs7: universal access to electricity by 2030. Efficient planning of distribution networks is a complex and multivariate task, which is usually split into multiple subproblems to reduce the number of variables. The present work addresses the problem of optimal secondary substation siting, by means of different clustering techniques. In contrast with the majority of approaches found in the literature, which are devoted to the planning of MV grids in already electrified urban areas, this work focuses on greenfield planning in rural areas. K-means algorithm, hierarchical agglomerative clustering, and a method based on optimal weighted tree partitioning are adapted to the problem and run on two real case studies, with different population densities. The algorithms are compared in terms of different indicators useful to assess the feasibility of the solutions found. The algo... [more]

Waste incineration air pollution control (APC) residues require pretreatment before landfilling because these types of residues encompass pollutants from an incineration gas stream. The environmental concerns of APC residues consist of a risk of leaching and subsequent release of potentially harmful substances that occur under environmental exposure. The stabilization/solidification (S/S) method of incineration residues is one of the most applied technologies for hazardous incineration residues. Portland cement is commonly used as a binder material in S/S for pollutant encapsulation, in order to change the hydrological characteristics of the landfilled material. Based on previous research, an innovative S/S method for APC residues is investigated, meant to replace Portland cement with cement-like material made from lignite fly ash (FA). To do this, a lab-scale landfill was created through the promoted S/S method and exposed to the environment for 12 months. Thus, this article assesses... [more]

Full-electric boats are an expression of recent advancements in the area of vessel electrification. The installed batteries can suffer from poor cold-start performance, especially in the frigid season and at higher latitudes, leading to driving power limitations immediately after startup. At state, the leading solution is to adopt a dedicated heater placed on the common cooling/heating circuit; this implies poor volume, weight, and cost figures, given the very limited duty cycle of such a part. The Heater-in-Converter (HiC) technology allows removing this specialized component, exploiting the power electronics converters already available on board: HiC modulates their efficiency to produce valuable heat (pseudo-cogeneration). In this work, we use the model-based approach to design this system, which requires heating power minimization to fulfill power electronics limitations, while guaranteeing the user-expected startup time to full power. A multistage model is used to get the yearly v... [more]