The Korean government has announced plans to supply electrified buses to achieve decarbonization in the transportation sector and to create next-generation growth engines. Although a multitude of technical and political studies have been conducted to support the successful introduction of electrified buses, studies on the attitudes and perceptions of passengers toward electrified buses remain insufficient. To evaluate the perceptions and preferences of potential passengers toward the specific attributes of electrified buses, this study performed an online survey (N = 586) that includes people who had experienced travel on public buses. Values of the relative importance of eight different attributes—safety, ride comfort, environmental friendliness, exterior design, cleanliness, crowding, seat comfort, and convenience getting on/off—were evaluated using the best-worst scaling method. The results showed that safety (share of preference: 41.3%) was the most important attribute when using e... [more]

The Environmental Kuznets Curve (EKC) hypothesis establishes the existence of an inverted U-shaped relationship between income and environmental deterioration. This paper studies the relationship between the energy mix and pollutant emissions and uses an environmental dynamic general equilibrium model to carry out a structural estimation of the EKC hypothesis. The model considers a three-input production function, including energy. Energy is a composite of fossil fuels and renewable energy sources. The flow of pollutant emissions depends on fossil fuels’ consumption, which accumulates in a pollution stock, resulting in a negative externality that adversely impacts aggregate productivity. Simulations of the model support the existence of a steady-state EKC relationship between Gross Domestic Product (GDP) and the stock of pollution, where the negative slope side of the curve is very flat. We find that (i) the EKC hypothesis is only fulfilled when the elasticity of substitution between f... [more]

Lithium ion batteries are experiencing an increased success thanks to their interesting performances, in particular for electric vehicles applications. Their continuous technological improvements in the last years are providing higher energy density and lower manufacturing costs. However, the environmental performance of their supply chain is of paramount importance to guarantee a cleaner alternative to fossil-based solutions on the entire life cycle of the applications. This paper carries out a comprehensive review on the main aspects related to Li-ion batteries manufacturing, to support the readers in understanding the complexity of the subject and the main challenges and opportunities for the future developments of this technology. The paper discusses the expected future demand of batteries; the main aspects related to the supply chain, including existing assets, input materials and alternative technologies; the end-of-life of batteries; the environmental impacts; and the main geopo... [more]

China has committed to ambitious targets to reduce its carbon emissions in the next decades, in order to combat climate change and improve the environment. The realization of the targets depends on the fair and effective mitigation plans of all provinces. However, with varying ecological and environmental conditions and social-economic development, it is a critical issue to quantify the provinces’ efforts equally. This paper proposed a comprehensive fE index in coordinating ecology, equity and economy, by accounting for carbon emissions and sinks to characterize provincial carbon emission status in China, from 2000 to 2017, which shows a spatial pattern of “boundary high, central low”. The provinces with higher fE value (>1.5) in boundary areas can be seen as “relative equality” provinces with good ecology circulation, equity and economic efficiency. The provinces with lower fE value (<0.7) in central areas around Bohai Bay are regarded as “severe inequality” provinces, and are iden... [more]

To combat global climate change moving towards sustainable, mobility is one of the most holistic approaches. Hence, decarbonization of the transport sector by employing electric vehicles (EVs) is currently an environmentally benign and efficient solution. The EV includes the hybrid EV (HEV), the plug-in hybrid EV (PHEV), and the battery EV (BEV). A storage system, a charging station, and power electronics are the essential components of EVs. The EV charging station is primarily powered from the grid which can be replaced by a solar photovoltaic system. Wide uptake of EVs is possible by improving the technologies, and also with support from the government. However, greenhouse gas emission (GHG) saving potential of the EV is debatable when the required power to charge the EV comes from traditional fossil fuel sources.

Although the chassis dynamometer type approval test considers real-world conditions, there are a few limitations to the experimental test environment that may affect gaseous or particulate emissions such as road conditions, traffic, decreasing tire pressure, or fluctuating ambient temperature. Furthermore, the real driving emission (RDE) test takes a long time, and it is too long to repeat under different experimental conditions. The National Institute of Environmental Research (NIER) test modes that reflect the driving pattern of Korea are not certification test modes, but can be used to evaluate the influence of traffic conditions because these modes consist of a total of 15 test modes that vary according to average speed. The use of the NIER #03, #09, and #13 modes as low-, medium-, and high-speed modes allow for gaseous and particulate emissions to be measured and analyzed. Additionally, the worldwide harmonized light-duty vehicle test procedure (WLTP), the certification mode of Eu... [more]

In South Korea, we are aiming for net zero energy use apartment home structures. Since the apartment structure in South Korea is generally a high-rise of 10 or more floors, the types of renewable energy applicable are limited to photovoltaic (PV) panels, solar collectors installed on the wall, or a photovoltaic thermal (PVT) hybrid panel combining both. In this study, the effect of PV, ST (Solar Thermal), and PVT systems on greenhouse gas reduction was analyzed using TRNSYS18. All three systems showed maximum CO2 reductions at 35° facing south. PV, ST, and PVT showed CO2 reductions of 67.4, 114.6, and 144.7 kg_CO2/m2·year, respectively. Compared to those values, when installed on a wall (slope of 90°), CO2 reduction is about 35−40% less and about 20% less at a slope of 75°. ST and PVT installed on the vertical wall have a greater greenhouse gas reduction effect than the PV installed at the optimal slope of 35°. Since the CO2 reduction difference among SW, SE, and azimuthal S is within... [more]

The Smart Meter Rollout Programme in the UK has required energy suppliers to offer new smart meters to customers to provide near real-time energy use information and enable two-way communication between the meter and the central system. The provision was expected to result in meaningful energy reductions, but recent estimates suggest that these reductions may be as low as 2%. This paper contributes to the ongoing debate about the effectiveness of smart meters and in-home energy displays by providing insights on energy feedback perceptions from a series of focus groups with postgraduate consumers. In addition to domestic energy use, the study investigated how participants perceived their energy use at work and how they perceived the energy reduction efforts of their institutions and employers. A laddered and projective methodology was used to more deeply question participant perceptions and reveal their attitudes. The analysis of responses revealed a limited awareness around energy effi... [more]

This study looks at the global trajectory of the relationship between GDP (gross domestic product) and CO2 (carbon dioxide) emission in the time-series, comparative, and transitional point of view (from Y1992 to Y2014). It sets up a measurement framework and compares thirty-seven countries (thirty-six OECD countries and China) through the fuzzy-set ideal type analysis while focusing on the comparative and relational types. This research found that economic growth (GDP) and environmental problems (CO2 emissions) are tied together in a very solid path-dependent relationship. Particularly, the analysis of comparisons among OECD countries and China shows that the relationship between GDP and CO2 emissions is very firmly coupled, unlike the previous non-combination of one-dimensional statistics that are based on the environmental Kuznets curve (EKC) hypothesis. In short, it draws out and highlights the research implications that the existing conventions regarding the relationship between su... [more]

Energy systems face great challenges from both the supply and demand sides. Strong efforts have been devoted to investigate technological solutions aiming at overcoming the problems of fossil fuel depletion and the environmental issues due to the carbon emissions. Hybrid (activated by both renewables and fossil fuels) distributed energy systems can be considered a very effective and promising technology to replace traditional centralized energy systems. As a most peculiar characteristic, they reduce the use of fossil sources and transmission and distribution losses along the main power grid and contribute to electric peak shaving and partial-loads losses reduction. As a direct consequence, the transition from centralized towards hybrid decentralized energy systems leads to a new role for citizens, shifting from a passive energy consumer to active prosumers able to produce energy and distribute energy. Such a complex system needs to be carefully modelled to account for the energy intera... [more]

The use of biomass has increased significantly in recent years. In this context, the use of not valued high-potential biomass (NVHPB) is emerging as a suitable alternative. This is the case of pruning vine, pruning kiwi, scrub (heather, gorse, broom) and forest pruning. The objective of this research was to study the potential of six selected agroforestry biomasses as biofuels in thermochemical processes. For that purpose, biomass was collected by specific machinery. Proximate and ultimate analyses were carried out as well as the inorganic compounds’ determination. Then, natural and forced drying were conducted. Low heating values (LHV) between 17 and 20 MJ/kg (dry basis) were achieved in all analyzed cases. Granulometric reduction, biomass classification and densification took place. Finally, energy recovery tests through microcogeneration were carried out. Values close to 97% in cogeneration efficiency were reached (9% net electric yield and 88% thermal yield), offering an alternativ... [more]

Even though biofuel production from microalgae has become more and more attractive in recent years, it is limited especially by the high cost of microalgae cultivation. However, microalgae can be grown in wastewater in order to reduce their production cost and, at the same time, the polluting impact of wastewaters. Winery wastewaters, which are abundantly released from the wine making process, have a large pollution impact related to their high loads of total solids, chemical oxygen demand (COD) and polyphenol concentration. In this research work a co-culture of Chlorella vulgaris and Arthrospira platensis was used to treat three different winery wastewaters from different steps of the wine production process, in order to produce low-cost biomass intended for biofuel production. Growth of the co-culture and reduction of wastewater pollutant impact were followed by daily determinations of biomass concentration, COD and polyphenol content. The highest productivities of biomass (0.66 gDry... [more]

Existing building stock represents potential for energy saving renovations. Energy savings and indoor climate comfort are key demands for sustainable building refurbishment. Especially in schools, indoor comfort is an extremely important issue. A case study of energy consumption in selected school buildings in temperate climatic conditions of Central Europe region was performed. The studied buildings are representatives of various school premises constructed throughout the last century. The evaluation was based on data analysis of energy audits. The goal was aimed at assessment of the school building envelopes and their influence on energy consumption. One of the studied schools was selected for detailed evaluation. The school classroom was monitored for indoor thermal and visual environments. The monitoring was performed to compare the current state and renovation scenarios. Results of the evaluation show that the school buildings are highly inefficient even if renovated. Indoor clima... [more]

Coal cities are an essential impetus for economic development and urbanization processes in China. However, a series of environmental issues provoked by resource exploitation cause the environmental sustainability of coal cities to face enormous challenges. Therefore, on the basis of the time series data of Yulin City from 1996 to 2017, this paper explores the nexus between socioeconomic development and industrial “three wastes” emissions by adopting the Tapio decoupling model, the environmental Kuznets curve (EKC) hypothesis, and the vector auto-regressive (VAR) model. The results show that Yulin’s economic development remains in an extensive stage and will not decouple from the environmental pollution in a short time. Except for the nexus of industrial solid waste and economic growth, which is an inverted U-shaped, the EKC hypothesis is not valid for industrial wastewater and industrial waste gas. Through the VAR (2) model, the impact of per capita gross domestic product (GDP) on ind... [more]

The global energy matrix is going to embrace more and more renewable-based combined energy systems. Therefore, multi-generation energy systems, like CHPs (combined heat and power) could be extremely beneficial for such integrated energy systems. Also, the trend is toward 100% sustainable production where both renewable and waste energy sources are of special value. Especially, in Europe, waste incineration has received special attention over the past decades, as not only it is a smart method of waste disposal, but also a measure of cheap and environmentally friendly energy production. This study proposes a municipal waste-driven tri-generation (cold, heat, and power) system and assesses how this solution helps for easier integration of energy sectors and having a more sustainable chain of energy supply. Then, the solution is comprehensively analyzed over thorough thermodynamic, thermoeconomic, and thermoenvironmental investigations. The results of the assessments show that the proposed... [more]

The development and utilization of wind energy has alleviated the problems of energy shortage and environmental pollution; however, it caused many negative impacts due to suboptimal site selections. This study proposes an innovative method integrating Geographic Information System (GIS), fuzzy Analytic Hierarchy Process (FAHP), and fuzzy VIšekriterijumsko KOmpromisno Rangiranje (VIKOR) for site selection of wind farms in the Wafangdian region, China. The uncertainties caused by subjective judgments of the stakeholders were tackled by the FAHP method firstly, where weight values of six criteria were identified. Next, the fuzzy VIKOR method and GIS tool were used to generate the Qi value of each location for ranking their appropriate degrees for wind energy development. The results demonstrated that the middle and upper parts of the studied area are suitable for the exploitation of wind energy, while the central and eastern areas are unfavorable. The influences exerted by various weight... [more]

Damages caused by wildfires in California due to transmission line failures have increased significantly in recent years. Curtailment of electric service in areas under fire threat has been implemented to avoid these wildfires. Results from this research indicated that 24% of California’s cities are at risk of wildfire, while 52% are at risk of blackout. These blackouts have resulted in significant financial losses and risk to life and health. Undergrounding current transmission lines has been proposed as a long-term solution. However, undergrounding lines would take decades to complete and increase average monthly electric bills from $80 to $260. This research investigated shortening the length of the electricity supply chain, supplying affected communities with onshore and offshore wind energy. Results showed good wind energy potential in locations near affected cities. Distance analyses revealed that more than two hundred cities (population 5.5 million) can be served by existing win... [more]

The paper presented herein investigates the effects of using supplementary cementitious materials (SCMs) in quaternary mixtures on the compressive strength and splitting tensile strength of plain concrete. In addition, environmental benefits resulting from the proposed solutions were analysed. A total of four concrete mixtures were designed, having a constant water/binder ratio of 0.4 and total binder content of 352 kg/m3. The control mixture only contained ordinary Portland cement (OPC) as binder, whereas others incorporated quaternary mixtures of: OPC, fly ash (FA), silica fume (SF), and nanosilica (nS). Based on the obtained test results, it was found that concretes made on quaternary binders containing nanoadditives have very favorable mechanical parameters. The quaternary concrete containing: 80% OPC, 5% FA, 10% SF, and 5% nS have shown the best results in terms of good compressive strength and splitting tensile strength, whereas the worst mechanical parameters were characterized... [more]

The aim of this study is to define the features that smart buildings should fulfil in order to be compatible with the overall context of the smart city and to introduce a new evaluation framework of Smart Buildings Integration into a Smart City (SBISC). By analysing scientific literature as well as existing international and local project examples, the features of smart buildings that are expected to be adopted in smart cities were identified. The SBISC evaluation methodology was developed and applied to a set of selected projects. The literature review revealed that the smart building and smart city concepts were developed in different time frames and by different stakeholders and, thus, need to be realigned. The most important aspect is to employ in a smart building all the functionalities proposed by the smart areas of the city and vice versa by enabling the recommended features of smart materials, smart building services, and smart construction to serve for the surrounding systems.... [more]

This study explores the degree and change of informational efficiency of the European Union (EU) carbon emission trading market using an asymmetric multifractal detrended fluctuation analysis (A-MF-DFA) method, which allows asymmetry. For this purpose, we analysed the daily price series of the European Emissions Market, which is operated according to the European Union Emissions Trading Scheme. This carbon market is the most active and has the largest trading volume. The data covers the period (from 4 August 2005 to 31 December 2019). The main results are summarised as follows. First, there is a multifractal feature in the price return movements of the EU carbon trading market, which behaves differently in the upward and downward periods of the market. Second, the informational efficiency of the carbon emission market has changed over time, with Phase I having the lowest informational efficiency and Phase III having the highest informational efficiency. These results indicate that info... [more]

Run-time profiling of software applications is key to energy efficiency. Even the most optimized hardware combined to an optimally designed software may become inefficient if operated poorly. Moreover, the diversification of modern computing platforms and broadening of their run-time configuration space make the task of optimally operating software ever more complex. With the growing financial and environmental impact of data center operation and cloud-based applications, optimal software operation becomes increasingly more relevant to existing and next-generation workloads. In order to guide software operation towards energy savings, energy and performance data must be gathered to provide a meaningful assessment of the application behavior under different system configurations, which is not appropriately addressed in existing tools. In this work we present Containergy, a new performance evaluation and profiling tool that uses software containers to perform application run-time assessm... [more]

This paper describes the development and characterization of a smart garment for monitoring the environmental and biophysical parameters of the user wearing it; the wearable application is focused on the control to workers’ conditions in dangerous workplaces in order to prevent or reduce the consequences of accidents. The smart jacket includes flexible solar panels, thermoelectric generators and flexible piezoelectric harvesters to scavenge energy from the human body, thus ensuring the energy autonomy of the employed sensors and electronic boards. The hardware and firmware optimization allowed the correct interfacing of the heart rate and SpO2 sensor, accelerometers, temperature and electrochemical gas sensors with a modified Arduino Pro mini board. The latter stores and processes the sensor data and, in the event of abnormal parameters, sends an alarm to a cloud database, allowing company managers to check them via a web app. The characterization of the harvesting subsection has shown... [more]

Building energy savings and occupant thermal comfort are the main issues in building technology. As such, the development of energy-efficient heating, ventilation, and air-conditioning (HVAC) systems and the control strategies of HVAC systems are emerging as important topics in the HVAC industry. Variable refrigerant flow (VRF) systems have efficient energy performance, so the use of VRF systems in buildings is increasing. However, most studies on VRF systems focus on improving mechanical efficiency, with few studies on energy-efficient control while satisfying the thermal comfort of occupants. The goal is to estimate the energy-saving potential of adjusting the temperature set-points and dead-band (range) in VRF air-conditioned building. To do so, we analyzed the influence of control strategies of a VRF system on human thermal comfort and energy consumption using a simulation method. The results showed that energy consumption can be reduced by 25.4% for predicted mean vote (PMV)-based... [more]

Growing economies need green and renewable energy. Their financial development can reduce energy consumption (through energy-efficient technologies) and replace fossil fuels with renewable ones. Gas turbine engines are widely used in transport and industry. To improve their economic attractiveness and to reduce harmful emissions, including greenhouse gases, alternative fuels and waste heat recovery technologies can be used. A promising direction is the use of alcohol and thermo-chemical recuperation. The purpose of this study is to estimate the economic efficiency and carbon dioxide emissions of an alcohol-fueled regenerative gas turbine engine with thermo-chemical recuperation. The carbon dioxide emissions have been determined using engine efficiency, fuel properties, as well as life cycle analysis. The engine efficiency was maximized by varying the water/alcohol ratio. To evaluate steam fuel reforming for a certain engine, a conversion performance factor has been suggested. At the op... [more]

PV waste management will gain relevance proportionally to the amounts of waste that are expected to arise with the phasing-out of old installations in the upcoming years and decades. The Life Cycle Assessment (LCA) methodology is used here to analyze the environmental performance of photovoltaic systems and the waste management methods that have been developed recently. Several LCA studies have already been performed for PV technologies, but in most cases these do not include the end of life stage, thus there is still uncertainty about the impacts of recycling on the environmental footprint of PV electricity. The present study offers a more detailed analysis of different end-of-life approaches for the main photovoltaic technologies that are found on the market. The results from the analysis demonstrate that recycling has the potential to improve the environmental profile of PV electricity but at the same time there is room for further improvements in developing dedicated recycling tech... [more]