Energy-related Aspects Research Articles

Application of artificial intelligence to predict energy consumption and thermal efficiency of hybrid convection-radiation dryer for garlic slices

This study aims to examine the energy-related aspects of a hybrid convection-radiation drying technique employed in the drying process of garlic slices. Several factors, including infrared radiation intensity (1500, 2000, and 3000 W/m2), air temperature (40, 50, and 60 °C), and airflow rates of the drying chamber (0.7, 1.0, and 1.5 m/s) were evaluated to optimize the responses of drying time (min), energy consumption (kJ), thermal efficiency (%), and specific energy consumption (MJ/kg). Furthermore, an Artificial Neural Network model was employed to predict the effects of the parameters above on the drying system's specific energy consumption, energy consumption, drying time, and thermal efficiency. The obtained data were analyzed using a self-organizing map and principal component analysis. Interestingly, the findings showed that increasing the air temperature and infrared radiation intensity led to shorter drying times, while higher airflow rates resulted in longer drying durations. Additionally, it was found that higher infrared intensity and air temperature, combined with lower airflow rates, improved the energy indices. Increasing the air velocity to 1.0 and 1.5 m/s at the same air temperature and radiation intensity resulted in a considerable increase in drying time by 9 and 22.7%, respectively. The lowest efficiency value of 10.1% was observed at 40 °C temperature and an air velocity of 1.5 m/s. The Artificial Neural Network model demonstrated high accuracy with a Root Mean Square Error of 0.05 and an overall accuracy of (95%) in predicting the drying parameters. Notably, the self-organizing map visualization revealed that higher air temperatures and radiation corresponded to lower drying times, energy consumption, and specific energy consumption. Conversely, higher airflow rates resulted in increased drying time and energy consumption. The present study suggested that 60 °C, 3000 W/m2 and 0.7 m/s are optimum conditions for efficiently drying garlic slices under the hybrid dryer. This investigation addresses the limitations and deficiencies of previous work on energy optimization and efficiency analysis of garlic under a hybrid dryer with infrared heating systems. Further studies on the economic feasibility of applying such a system for sample drying and the impact of drying on the thermal behaviors of the products need additional investigation.

A model-based approach for formal verification and performance evaluation of energy harvesting architectures in IoT systems: A case study of a long-term healthcare application

Energy harvesting plays a significant role in the Internet of Things (IoT). Indeed, although numerous approaches exist to limit the system’s power consumption, the energy provided by the battery remains constrained, thereby limiting the system’s lifetime. Energy harvesting represents an interesting technique that allows a set of devices in an IoT architecture to operate for a potentially infinite time without the need for battery replacement or recharge. This work presents a formal modeling framework for the performance evaluation of energy harvesting architectures and strategies in IoT systems. We present a model-based approach using UPPAAL to model and analyze IoT device lifetimes and capture the energy-related behavior of nodes and various energy harvesters. Furthermore, the model is calibrated using measurements acquired from real-life IoT applications to demonstrate the effectiveness of the proposed model and its ability to investigate various energy-related aspects.

Unraveling the Knowledge Roadmap of Building Policy Mixes: A Scientometric Analysis

Improving energy efficiency and reducing carbon emissions from buildings are crucial for achieving sustainable development. To realize these goals, it is essential to adopt a policy mix. However, despite much effort in this field, there is a lack of comprehensive understanding on building policy mixes (BPMs), which challenges building sustainability. To address this research gap, this study attempted to uncover the knowledge landscape of BPM through scientometric analysis. By employing methods such as keywords co-occurrence analysis, clustering analysis, co-citation analysis, and research trend analysis, this study systematically examined the current status, hot topics, underlying knowledge framework, knowledge domains, and frontiers of BPM research. The findings revealed that the existing BPM research primarily focuses on various aspects, including policy-related topics such as building energy efficiency policies and policy instruments, as well as topics like green affordable housing, hindering factors, carbon pricing, use obligation, construction waste reduction, and sustainable construction methods. Furthermore, the analysis identified research frontiers in BPM, encompassing policy considerations (e.g., building efficiency policy, split incentive, carbon tax, and carbon pricing), energy-related aspects (e.g., consumption, green transition), political dimensions (e.g., governance, management), building-related factors (e.g., green building, retrofitting), the innovation system, and the evolutionary game. Based on these findings, this study suggests that future research in BPM can deepen insight into interdisciplinary policy mixes by focusing on policy strategies, processes, and features. This study contributes to a holistic understanding of BPM and offers insightful guidance for both researchers and practitioners seeking to advance sustainable practices in the building sector.

Introducing new green machining technology to enhance process performance and reduce environmental pollution in the metal processing industry.

The pursuit of enhanced cooling and lubrication methods for machining processes that are energy-efficient, environmentally friendly, and cost-effective is receiving significant attention from both academia and industry. The reduction of CO2 emissions is closely tied to electrical and embodied energy consumption. This study introduces a novel LN2 oil-on-water (LNOoW) cooling/lubrication (lubricooling) approach for the machining of Ti-6Al-4V alloy. Machinability aspects, energy-related aspects, environmental-related aspects, and economic aspects are measured and compared. More specifically, surface quality, electrical energy, cutting forces, and tool wear were measured in machinability aspects. Similarly, specific total energy and specific cumulative Energy Demand (S_CED), specific carbon emission, and production costs were measured to investigate the energy and environmental and economic aspects, respectively. The LNOoW provided the best machinability results compared with other approaches. Result found that LNOoW produced 37.5% better surface quality, removed 159.17% more material, and reduced 50.56% specific cutting energy and 53.63% specific costs as compared to traditional dry cutting conditions. The 39% increment in specific carbon emissions observed in the LN2 oil-on-water (LNOoW) approach in comparison to the dry-cutting method can be mitigated through the implementation of sustainable practices in the production of liquid nitrogen (LN2). The information provided in this study serves as a valuable resource for the development of environmentally friendly machining processes. The study also helps get the sustainable development goals (SDGs) of the United Nations.

Sustainable Energy Data Centres: A Holistic Conceptual Framework for Design and Operations

Data Centres serve as the foundation for digital technologies in the energy sector, enabling advanced analytics, optimization, and automation. However, their rapid growth can exert a substantial influence on the environment due to their energy consumption, water utilization, and production of electronic waste. This research begins with an energy overview of the setup and operations of data centres, highlighting their key components and infrastructure, and emphasizing their crucial role in managing energy resources and driving the energy sector’s digital technologies. Building upon this understanding, a holistic framework is proposed to tackle energy sustainability concerns in data centres, with a focus on energy-related aspects. The framework places emphasis on three primary sustainability metrics, namely energy efficiency, water consumption, and waste management. It underscores the significance of green building design principles and energy-efficient equipment as crucial constituents of sustainable data centre infrastructure. The framework delineates optimal energy operational best practices encompassing virtualization and consolidation, effective cooling tactics, and energy management and monitoring, all aimed at reducing energy consumption and enhancing energy performance. Furthermore, the framework emphasizes the significance of incorporating energy-related sustainability metrics into decision-making procedures and adhering to regulatory standards for energy efficiency. Through adherence to this framework, data centres’ environmental impact can be mitigated and a positive contribution towards a sustainable future can be made, particularly in the realm of energy conservation and optimization.

Impact of FinTech, governance and environmental taxes on energy transition: Pre-post COVID-19 analysis of belt and road initiative countries

This study investigated the FinTech, governance and environmental tax factors affecting energy transition in the Belt and Road Initiative (BRI) partner countries, in the context of COVID-19. A balanced panel representing 148 BRI partner countries, comprising 78 members from high- and upper-middle income developed countries and 72 members from low- and lower-middle income developing countries, with reference to the 2013–2021 period, was used for this study. This study employed a two-step system generalised method of moments (GMM) model, which was validated through the two-stage least squares (2SLS) method. The findings indicate that FinTech, globalization, and environmental taxes contributed significantly and positively to the energy transition in the entire BRI sample. However, inflation and COVID-19 had a significant negative impact on the energy transition, whereas urbanisation negatively and insignificantly impacted the energy transition. In developed countries, all variables except urbanisation, inflation, and COVID-19 had a significantly positive effect upon the energy transition. On the other hand, in developing countries, while FinTech, environmental taxes, and high-level governance had a significant positive impact, other factors negatively impacted the energy transition. Additionally, this study suggested a balanced policy implication and future work areas that would be helpful to policymakers, governments, and academia for boosting and exploring energy transition and related aspects.

Recycling waste sources into nanocomposites of graphene materials: Overview from an energy-focused perspective

Abstract In line with the global recognition of waste-to-wealth concept aiming for circular economy, scientific articles are published in greatly increasing number on the eco-friendly and sustainable utilization of carbon nanocomposites. However, control on the structure and properties of waste-derived carbon nanomaterials still requires substantial future research. In this review, recycling materials into nanocomposites containing graphene are narrated by overviewing all the 120 publications currently available in the literature including their pioneering study in 2012 and their recent developments until 2022, focusing on energy-related aspects of functional graphene-based nanocomposites. Interestingly, almost all currently available sources report on composites in which graphene is a high value-added filler or matrix, and only the other phase originates from wastes. Flexibility of process parameters of pyrolysis methods enables the synthesis of biomass-derived graphene composites for virtually any kind of industrial applications. Biomass often acts both as carbon and SiO2 source, while only a few percentages of graphene material induce significant changes in their physicochemical properties. Utilization of wastes for energetic composites increases abruptly due to their outstanding price-to-value ratio and reusability. Future perspectives and current green chemistry or human health related challenges are also discussed to pave ways for new developments using unexplored waste sources.

Utilizing Extensive-Form Games for Energy-aware Production Plan Adaptation in Modular Skill-based Production Systems

Modular production systems provide an important basis to react more flexibly to changing and more individual production requirements. A challenge hereby is an appropriate production planning and scheduling that considers the capabilities and the degrees of freedom of these systems, which can be al-gorithmically optimized for their relevance. A great importance is also given to the aspect of energy-efficient production, which can be included in the planning as well as in its execution on the modular level. The main objective of the paper is to show the relevance of the adaptability of production plans within modular production systems from an energetic point of view, with special focus on electrical energy. It is considered on how modular production systems can be modeled, based on the current state of the art and from the perspective of the capability- and skill-based approach for energy-aware skill usage. Furthermore, it is examined how pre-optimized scheduling for production systems can be adapted by production modules. For the energy-related optimization an extensive-form game model is provided. The scheduler and the production modules are considered as players and strategies of the modules are selected based on their modeled capabilities by using their best response under energy-related aspects. The results of a simulation with prototypical implementation for energy-optimized adaptation, based on extensive-form games, and possible application for unforeseen event handling are presented and discussed.

Selected Energy Consumption Aspects of Sensor Data Transmission in Distributed Multi-Microcontroller Embedded Systems

Wireless network devices are currently a hot topic in research related to human health, control systems, smart homes, and the Internet of Things (IoT). In the shadow of the coronavirus pandemic, they have gained even more attention. This remote and contactless distributed sensing technology enabled monitoring of vital signs in real-time. Many of the devices are battery powered, so appropriate management of available energy is crucial for lengthening autonomous operation time without affecting weight, size, maintenance requirement, and user acceptance. In this paper, we discuss energy consumption aspects of sensor data transmission using wireless Bluetooth Low Energy Mesh Long Range (BLE-M-LR) technology. Papers in the field of energy savings in wireless networks do not directly address the problem of the dependence of the energy needed for transmission on the type and degree of data preprocessing, which is the novelty and uniqueness of this work. We built and studied a prototype system designed to work as a multimodal sensing node in a compound IoT application targeted to assisted living. To analyze multiple energy-related aspects, we tested it in various operation and data transmission modes: continuous, periodic, and event-based. We also implemented and tested two alternative sensor-side processing procedures: deterministic data stream reduction and neural network-based recognition and labeling of the states. Our results reveal that event-based or periodic operation allows the node for years-long operating, and the sensor-side processing may degrade the power economy more than it benefits from savings made on transmission of concise data.

Topologically-mediated energy release by relativistic antiferromagnetic solitons

Magnetic solitons offer functionalities as information carriers in multiple spintronic and magnonic applications. However, their potential for nanoscale energy transport has not been revealed. Here we demonstrate that antiferromagnetic solitons, e.g. domain walls, can uptake, transport and release energy. The key for this functionality resides in their relativistic kinematics; their self-energy increases with velocity due to Lorentz contraction of the soliton and their dynamics can be accelerated up to the effective speed of light of the magnetic medium. Furthermore, their classification in robust topological classes allows to selectively release this energy back into the medium by colliding solitons with opposite topology. Our work uncovers important energy-related aspects of the physics of antiferromagnetic solitons and opens up the attractive possibility for spin-based nanoscale and ultra-fast energy transport devices.

Electric vehicle charging potential from retail parking lot solar photovoltaic awnings

This study investigates the energy related aspects of developing electric vehicle (EV) charging stations powered with solar photovoltaic (PV) canopies built on the parking infrastructure of large-scale retailers. A technical analysis is performed on parking lot areas located in the highest EV market coupled with charge station rates and capacities of the top ten EV. The results of a case study show a potential of 3.1 MW per Walmart Supercenter in the U.S., which could provide solar electricity for ∼100 EV charging stations. In the entire U.S., Walmart could potentially deploy 11.1 GW of solar canopies over only their Supercenter parking lots providing over 346,000 EV charging stations with solar electricity for their customers covering 90% of the American public living within 15 miles of a Walmart. This novel model could be adopted by any box store with the solar electricity sold for EV charging at a profit solving community charging challenges. In addition, however, the results for the first time indicate store owners could increase store selection and profit by providing free PV-EV charging for their customers with four mechanisms. Overall the results of this study are promising, but future work is needed to provide more granular quantification of the benefits of this approach.

Computer aided calculus of the radial bridge kinetic energy of a sedimentation tank

The paper presents energy related aspects of a circular sedimentation tank’s radial bridge in order to assess the effectiveness of the equipment and to propose optimisations. In steady state conditions ETotal = EKinetic + ELosses where ETotal is provided by an electric motor of power P and the kinetic energy is , where . Several methods to assess the value of the J moment of inertia were explored. Finally, the moment of inertia is computed using an analytical method, by dividing the radial bridge in NC ‘simple shape’ components and by the use of an original C++ software consisting of >1700 computer code lines. Being a flexible and heavily parameterized original software, an optimised version of the radial bridge geometry was considered, for which Jopt = 83.57%. Jini We know the time in which a complete rotation is performed, T, therefore we compute ω and the kinetic energy. It results ELosses and we noticed that, because ω has a very small value, most of the ETotal energy is spent to cover the ‘losses’. The computation of the J moment of inertia allowed us to conclude regarding the effectiveness of the equipment and to extent the library of C++ header files to be reused in other software projects for the development of the hybrid models in mechanical engineering.

Steam, dry and autothermal methane reforming for hydrogen production: A thermodynamic equilibrium analysis

Environmental issues of fossil fuels use in energy systems are boosting research in the field of H2 generation. Although steam reforming is the most well-established process for H2 production, alternative thermochemical routes are emerging.The paper aims to compare three reforming processes: steam methane reforming, dry methane reforming and autothermal methane reforming. To this end, a thermodynamic equilibrium model is developed and validated via comparison with literature data. The influence of operating conditions on the performance of the reforming options is investigated, addressing chemical and energy-related aspects. Regarding the former, attention is focused on H2 yield and selectivity over CO and CO2. From the energy viewpoint, performance indices investigated include the lower heating value of syngas, the reformer thermal power requirement and the chemical energy increase of fuel at the reformer exit. An H2 production efficiency is also evaluated to directly compare steam, dry and autothermal methane reforming.The study revealed that moderate pressures and oxidant-to-methane ratios allow finding the best compromise between H2 production and process efficiency in all investigated reforming options; under these conditions, steam methane reforming performs better than dry methane reforming; however, when the reformer operates under autothermal conditions, the performance of dry methane reforming approaches that of steam methane reforming.

Wake-up radio-based data forwarding for green wireless networks

This paper presents G-WHARP, for Green Wake-up and HARvesting-based energy-Predictive forwarding, a wake-up radio-based forwarding strategy for wireless networks equipped with energy harvesting capabilities (green wireless networks). Following a learning-based approach, G-WHARP blends energy harvesting and wake-up radio technology to maximize energy efficiency and obtain superior network performance. Nodes autonomously decide on their forwarding availability based on a Markov Decision Process (MDP) that takes into account a variety of energy-related aspects, including the currently available energy and that harvestable in the foreseeable future. Solution of the MDP is provided by a computationally light heuristic based on a simple threshold policy, thus obtaining further computational energy savings. The performance of G-WHARP is evaluated via GreenCastalia simulations, where we accurately model wake-up radios, harvestable energy, and the computational power needed to solve the MDP. Key network and system parameters are varied, including the source of harvestable energy, the network density, wake-up radio data rate and data traffic. We also compare the performance of G-WHARP to that of two state-of-the-art data forwarding strategies, namely GreenRoutes and CTP-WUR. Results show that G-WHARP limits energy expenditures while achieving low end-to-end latency and high packet delivery ratio. Particularly, it consumes up to 34% and 59% less energy than CTP-WUR and GreenRoutes, respectively.

Net-Metering Compared to Battery-Based Electricity Storage in a Single-Case PV Application Study Considering the Lithuanian Context

Further increases in the number of photovoltaic installations in industry and residential buildings will require technologically and economically flexible energy storage solutions. Some countries utilize net-metering strategies, which use national networks as “virtual batteries.” Despite the financial attractiveness, net-metering faces many technological and economical challenges. It could also lead to the negative tendencies in prosumer behavior, such as a decrease in motivation for the self-consumption of photovoltaic (PV)-generated electricity. Batteries, which are installed on the prosumer’s premises, could be a solution in a particular case. However, the price for battery-based storage solutions is currently sufficiently unattractive for the average prosumer. This paper aimed to present a comparison of the economic and energy related aspects between net-metering and batteries for a single case study by considering the Lithuanian context. The net present value, degree of self-sufficiency, internal rate of return, payback time, and quantified reduction of carbon emission were calculated using a specially developed Prosumer solution simulation tool (Version 1.1, Delloite, Madrid, Spain) for both the PV and net-metering and PV and batteries cases. The received results highlight that the battery-based energy storage systems are currently not an attractive alternative in terms of price where net-metering is available; a rather radical decrease in the installation price for batteries is required.

Altering the reactivity of pristine, N- and P-doped graphene by strain engineering: A DFT view on energy related aspects

For carbon-based materials, in contrast to metal surfaces, a general relationship between strain and reactivity is not yet established, even though there are literature reports on strained graphene. Knowledge of such relationships would be extremely beneficial for understanding the reactivity of graphene-based surfaces and finding optimisation strategies which would make these materials more suitable for targeted applications. Here we investigate the effects of compressive and tensile strain (up to ±5%) on the structure, electronic properties and reactivity of pure, N-doped and P-doped graphene, using DFT calculations. We demonstrate the possibility of tuning the topology of the graphene surface by strain, as well as by the choice of the dopant atom. The reactivity of (doped) strained graphene is probed using H and Na as simple adsorbates of great practical importance. Strain can both enhance and weaken H and Na adsorption on (doped) graphene. In case of Na adsorption, a linear relationship is observed between the Na adsorption energy on P-doped graphene and the phosphorus charge. A linear relationship between the Na adsorption energy on flat graphene surfaces and strain is found. Based on the adsorption energies and electrical conductivity, potentially good candidates for hydrogen storage and sodium-ion battery electrodes are discussed.

The competitiveness of the national economy: energy-related aspects

The aim of the paper is to assess the competitiveness of national production in terms of its resources and energy supply. The authors present the dynamics of energy intensity of some countries and regions of the world and consider the relationship between the level of energy intensity and the competitiveness of national economies. Based on this relationship, countries are grouped depending on the type of the performance indicators of economies. Alternative energy is presented as a tool for improving efficiency of existing industries and for ensuring countries’ position in the world market. The increase in the share of renewable energy in total consumption served as a basis for studying experience of various countries in regulating the development of alternative energy followed by a grouping of methods. The paper analyses both methods associated with the positioning of alternative energy and its incorporation into the existing structure and methods aimed at stimulating the development of alternative energy.

Overview of BIM integration into the Construction Sector in European Member States and European Union Acquis

The amount of information involved in any construction project and the necessity of control of time, cost and waste, has established Building Information Modelling (BIM) as an integral part of construction sector towards achieving adequate communication of information among various parties involved in construction projects. Moreover, it can be considered as a valuable tool for the optimum selection of materials, systems and design decisions, regarding not only the improve of a structure’s performance, but also in terms of reducing its carbon footprint during its life cycle. The study attempts to present the integration of BIM into the national legislation of European Member States, with a special focus on the energy related aspects of BIM analysis. This study performs an overview of the introduction of BIM into different aspects and requirements of the EU Member States building practices, through a comprehensive literature and legislation review of relative legislative documents of the construction sector. According to the findings of this overview study, the concept of BIM has already been incorporated in many aspects of the Acquis of EU Member States, which is recognized as a valuable tool to be exploited by the construction sector, however there is still room for development in this area. The study has revealed that especially in the energy assessment of the built environment, BIM applications are still lacking from the European Legislation. Examples and good practices of employing BIM for the implementation of the European Energy targets in the building sector are also presented and discussed. The findings of this study aim to shed light on the needs and requirements in the field of BIM development for the construction sector, as well as to indicate gaps and weaknesses of the European Member States Acquis towards harmonizing with BIM practices.

Principles of passive solar architecture as means of improving health and thermal comfort aspects of indoor environment

The estimates are that we spend majority of our lifetime indoors. Therefore, the quality of indoor environment is crucial to our health. Thermal comfort is amongst the most energy-related aspects of comfort since the energy requirements for heating and cooling refer to more than a half of energy needs in buildings. Passive solar architecture, emerged from the archetypal builders’ responses to the natural environment, by using the energy of the sun for heating and cooling in the most economical and rational way- by applying the laws of physics. The key passive solar architectural principles aimed at achieving thermal comfort presented in the paper are: adaptive thermal comfort (the comfortable indoor temperature levels adjusting to the outside temperature), thermal zoning (variety in disposition and orientation of the different functional zones), and thermal mass (using building materials with ability to effectively store heat), all aimed at enhancing energy efficiency and providing a healthy indoor environment.

Environmental impact of microbial protein from potato wastewater as feed ingredient: Comparative consequential life cycle assessment of three production systems and soybean meal

Livestock production is utilizing large amounts of protein-rich feed ingredients such as soybean meal. The proven negative environmental impacts of soybean meal production incentivize the search for alternative protein sources. One promising alternative is Microbial Protein (MP), i.e. dried microbial biomass. To date, only few life cycle assessments (LCAs) for MP have been carried out, none of which has used a consequential modelling approach nor has been investigating the production of MP on food and beverage wastewater. Therefore, the objective of this study is to evaluate the environmental impact of MP production on a food and beverage effluent as a substitute for soybean meal using a consequential modelling approach. Three different types of MP production were analysed, namely consortia containing Aerobic Heterotrophic Bacteria (AHB), Microalgae and AHB (MaB), and Purple Non-Sulfur Bacteria (PNSB). The production of MP was modelled for high-strength potato wastewater (COD = 10 kg/m3) at a flow rate of 1,000 m3/day. LCA results were compared against soybean meal production for the endpoint impact categories human health, ecosystems, and resources. Soybean meal showed up to 52% higher impact on human health and up to 87% higher impact on ecosystems than MP. However, energy-related aspects resulted in an 8–88% higher resource exploitation for MP. A comparison between the MP production systems showed that MaB performed best when considering ecosystems (between 13 and 14% better) and resource (between 71 and 80% better) impact categories, while AHB and PNSB had lower values for the impact category human health (8–12%). The sensitivity analysis suggests that the conclusions drawn are robust as in the majority of 1,000 Monte Carlo runs the initial results are confirmed. In conclusion, it is suggested that MP is an alternative protein source of comparatively low environmental impact that should play a role in the future protein transition, in particular when further process improvements can be implemented and more renewable or waste energy sources will be used.