Hydrogen is fast becoming a new international “super fuel” to accelerate global climate change ambitions. This paper has two inter-weaving themes. Contextually, it focuses on the potential impact of the EU’s new Carbon Border Adjustment Mechanism (CBAM) on fossil fuel-generated as opposed to green hydrogen imports. The CBAM, as a transnational carbon adjustment mechanism, has the potential to impact international trade in energy. It seeks both a level playing field between imports and EU internal markets (subject to ambitious EU climate change policies), and to encourage emissions reduction laggards through its “carbon diplomacy”. Countries without a price on carbon will be charged for embodied carbon in their supply chains when they export to the EU. Empirically, we focus on two hydrogen export/import case studies: Australia as a non-EU state with ambitions to export hydrogen, and Germany as an EU Member State reliant on energy imports. Energy security is central to energy trade debat... [more]

A combined immersed boundary−lattice Boltzmann approach is used to simulate the dynamics of the fluid−structure interaction of a hollow sealing strip under the action of pressure difference. Firstly, the multiple relaxation times LBM model, hyper-elastic material model and immersed boundary method were deduced. According to the strain characteristics of hyper-elastic materials and the specific situation of friction between the elastic boundary and solid boundary, the internal force and the external force on the immersed boundary were discussed and deduced, respectively. Then, a 2D calculation model of the actual hollow sealing strip system was established, during which technical problems such as the equivalent wall thickness of the sealing strip and the correction of the stiffness of the contact corner were solved. The reliability of the model was verified by comparing results of FEM simulation of quasi-static deformation. Following this, the simulation results of three typical cases o... [more]

In the age of the impending climate crisis, and further forecast ecological catastrophes, humankind has begun to think with growing interest about replacing existing energy sources with renewable ones. An increasing number of people have begun to discuss the need to implement registries that collect information about the energy potential of specific parts of the environment we live in. Additionally, the simultaneous registration of installations used for obtaining energy from alternative sources is desirable. In addition to quantitative attributes, such databases should also contain comprehensive spatial information. Since, in the era of globalization, the creation of such databases ought to be standardized, the purpose of this study is to indicate the directions in which the cadastre of renewable energy sources should be developed by: (i) reviewing the solutions of renewable energy sources that have been described in the scientific literature; (ii) analyzing the content of selected ge... [more]

Balancing energy demand and supply will become an even greater challenge considering the ongoing transition from traditional fuel to electric vehicles (EV). The management of this task will heavily depend on the pace of the adoption of light-duty EVs. Electric vehicles have seen their market share increase worldwide; the same is happening in Portugal, partly because the government has kept incentives for consumers to purchase EVs, despite the COVID-19 pandemic. The consequent shift to EVs entails various challenges for the distribution network, including coping with the expected growing demand for power. This article addresses this concern by presenting a case study of an area comprising 20 municipalities in Northern Portugal, for which battery electric vehicles (BEV) sales and their impact on distribution networks are estimated within the 2030 horizon. The power required from the grid is estimated under three BEV sales growth deterministic scenarios based on a daily consumption rate r... [more]

There are several threats that require the control of the conditions of switching operations in the transmission grid. They result mainly from the negative effects of the high-value current, which may appear after the breaker is closed. Problems considering closing the power circuit breakers on a large standing phase angle (SPA) are often formulated by grid operators. The literature most often discusses the problem of SPA reduction, which allows the system to be restored without the risk of damaging the turbogenerator shafts. This reduction can be achieved by various operational solutions; most often, it is the appropriate adjustment of active power generation, sometimes backed up by partial load shedding. The subject of the presented article is a slightly different approach to the SPA problem. The method of determining the maximum value of SPA for which the connection operation allows to avoid excessive transitional torques was presented. With this approach, finding the maximum value... [more]

The Wumaying buried hill experienced multi-stage tectonic movements, which resulted in a complicated and unclear nature of the hydrocarbon accumulation process. To solve these problems, in this study—based on the structural evolution and burial−thermal history of the strata, using petrology, fluid inclusion microthermometry, geochemical analysis of oil and gas, Laser Raman spectrum, and fluorescence spectrum—the history of hydrocarbon charging was revealed, and the differences in hydrocarbon charging of different wells was clarified. The results indicate that the only source for Permian oil and gas reservoirs are Carboniferous−Permian coal-measure source rocks in the Wumaying buried hill. There are three periods of hydrocarbon charging. Under the channeling of faults and micro cracks, low-mature oil and gas accumulation was formed in the first period, and the accumulation time was 112−93 Ma. In the late Cretaceous, a large-scale uplift exposed and damaged the reservoirs, and part of th... [more]

With increasingly prominent environmental problems, controlling automobile exhaust has become essential to the environment. The fuel consumption of transportation is the critical factor that determines exhaust gas. By analyzing the naturalistic driving data of heavy-duty diesel trucks (HDDTs), this paper explored the influence of engine technical state, road features, weather, and temperature conditions on fuel consumption during driving. The detailed process is as follows: Firstly, we collected 1153 naturalistic driving data from 34 HDDTs and made a specific analysis and summary description of the data; secondly, by establishing a binary Logistic regression model, we quantitatively explored the influence of significant factors on the fuel consumption; meanwhile, based on quantitative analysis of factor’s effectiveness, this research used several machine learning algorithms (back-propagation neural network, decision tree, and random forest) to build fuel consumption predictors, and com... [more]

Greenhouse gas emissions are regarded as the cause of the rise in mean Earth temperature, the further increase of which may cause dramatic irreversible global changes. Their levels in Poland are some of the highest in the world. In this study, to evaluate the “Energy policy of Poland until 2040”, greenhouse gas and particulate matter emissions were compared in all Polish climatic zones using a typical meteorological year. A comparison was made between air-to-water, brine-to-water, and water-to-water devices. The electrical energy consumption and coefficient of performance were determined hourly in the heating season. The determining algorithm took a buffer tank or separating heat exchanger into consideration, when they were required, and electricity transmission efficiency. Subsequently the emissions were estimated for the present Polish energy mix and a mix proposed in the “Energy policy of Poland until 2040”. After implementing this policy all heat pumps will be energetically viable... [more]

The Euro 4 regulation, applicable since 2016 for L-category vehicles (i.e., two and three-wheelers, and mini cars) reduced the emission limits, but also introduced a new cycle, the WMTC (World Harmonized Motorcycle Test Cycle). The emission studies of Euro 4 motorcycles are limited, and most importantly there are no published studies comparing the results of different laboratories applying the new cycle. In this study we compared the particle and gaseous pollutants of one Euro 4 motorcycle measured in two laboratories in 2017 and 2020. The gaseous pollutant results had a variance (one standard deviation of the means) of 0.5% for CO2, 4−19% for CO, NOx, HC (hydrocarbons) and SPN (Solid Particle Number). The particulate matter mass results had higher variance of 50−60%. Additional tests with open configuration to mimic dilution at the tailpipe gave equivalent results to the closed configuration for the gaseous pollutants and SPN. The total particles (including volatiles) had significant... [more]

Energy-efficient building retrofits must be approached from three perspectives: law regulation approach, financial incentives approach, and practice approach. The concepts of zero energy building and life cycle energy building are presented as the basis for energy retrofits. Multi-criteria boards to assess the decision-making process are reviewed, analysed, and categorised under an architectonic perspective. Some examples are presented, with different packages of measures, from deep to non-invasive energy retrofits. Passive and active energy generation systems, together with control and management strategies, are the physical elements identified with the potential to improve buildings’ energy efficiency. From a practice approach, this literature review identifies the concept of performance-based architectural design to optimise the planning and design of buildings’ energy retrofits. In addition, tools such as Building Information Modelling are described as part of optimisation processe... [more]

This paper presents an algorithm for modeling electricity and natural gas consumption in a walking furnace with the use of artificial intelligence and simulation methods, depending on the length of the rolling campaign and the established rolling program. This algorithm is the basis for the development of a proposal for a set of minimum requirements characterizing the Best Available Techniques (BAT) for beam furnaces intended for hot rolling, taking into account the requirements set out in national regulations and the recommendations described in the BREF reference documents. This information should be taken into account when drawing up an application for an integrated permit, as well as when setting emission limit values. Based on the constructed algorithm, it was shown that depending on their type and technical specification, the analyzed projects will offer measurable economic benefits in the form of reducing the amount of energy consumed by 1,076,400 kWh during the implementation o... [more]

The work of traditional cyclones is based on the separation of solid particles using only the centrifugal forces. Therefore, they do not demonstrate high gas-cleaning efficiency, particularly in the cases where gas flows are polluted with fine solid particles (about 20 µm in diameter). The key feature of a new-generation multi-channel cyclone separator’s structure is that its symmetrical upgraded curved elements, with openings cut with their plates bent outwards, make channels for the continuous movement of the gas flows from the inflow opening to the central axis. The smoke flue of the vertical gas outflow is located near the cover of the separating chamber. The present work is aimed at studying the applicability of two various viscosity models and their modified versions to simulate aerodynamic processes in an innovative design for a multi-channel cyclone separator with a single inflow, using the computational fluid dynamics. The research results obtained in the numerical simulation... [more]

The EU’s energy policy is geared towards introducing changes in order to stop or avoid negative climate change. The determinants of the energy policies of Poland and Germany are presented along with the priorities until 2050. The possibilities of reducing the impact of energy on the environment were interpreted, emphasizing its common goal. Activities supporting the EU and maintaining the level of energy security are indicated. Possible negative effects in the social and health sphere are presented as a response to the failure to implement these demands. The literature was analyzed and proprietary questionnaires were carried out, and the results realized in the EU by the independent FBI Economic Department were implemented. On the basis of earlier pilot studies, variants of a successful transformation were implemented, assuming different roles performed by a citizen (entrepreneur). Opportunities to tackle climate change and global challenges have been identified based on innovation and... [more]

Through the integration of multiple energy carriers with related technologies, multi-energy systems (MES) can exploit the synergies coming from their interplay for several benefits towards decarbonization. In such a context, inclusion of Power-to-X technologies in periods of excess renewable electricity supply, removes the need for curtailment of renewable electricity generation. In order to achieve the environmental benefits of MES without neglecting their economic feasibility, the optimal design problem is as crucial as challenging and requires the adoption of a multi-objective approach. This paper extends the results of a previous work, by investigating hydrogen-based non-conventional storage for PV power in the eco-energetic optimization of an MES. The system under study consists of a reversible fuel cell (r-SOC), photovoltaic (PV), electric heat pump, absorption chiller and thermal storage, and allows satisfying the multi-energy needs of a residential end-user. A multi-objective l... [more]

It is important for the safety and good performance of a Li-ion battery module/pack to have an efficient thermal management system. In this paper, a battery thermal management system with a two-phase refrigerant circulated by a pump was developed. A battery module consisting of 240 18650-type Li-ion batteries was fabricated based on a finned-tube heat-exchanger structure. This structural design offers the potential to reduce the weight of the battery thermal management system. The cooling performance of the battery module was experimentally studied under different charge/discharge C-rates and with different refrigerant circulation pump operation frequencies. The results demonstrated the effectiveness of the cooling system. It was found that the refrigerant-based battery thermal management system could maintain the battery module maximum temperature under 38 °C and the temperature non-uniformity within 2.5 °C for the various operation conditions considered. The experimental results with... [more]

The thermal state of building elements is a combination of steady and transient states. Changes in temperature and energy streams in the wall of the building in the transient state are particularly intense in its outer layer. The factors causing them are solar radiation, ambient temperature and long-wave radiation. Due to the greater variability of these factors during the summer, the importance of the transient state increases at this time. The study analysed heat transfer in three aspects, temperatures in the outer, middle and inner parts of the wall, heat fluxes between these layers and absorption of solar energy, heat transfer coefficient on the wall exterior was also calculated. The analysis is based on temperature measurements at several depths in the wall and measurements of solar radiation. The subject of research is a solid brick wall. The results show that the characteristics of heat flow in winter and summer for the local climate show distinct differences. In the winter, the... [more]

The increase in global energy demand has led to increased research in harvesting solar energy. Solar energy is widely used in homes, electric vehicles and is a great solution to power remote areas. DC−DC converters are essential in extracting power from solar panels. One of the main problems in designing converters for solar energy applications is boosting the low output voltage of the solar panel to meaningful levels. While there are several topologies to achieve high gain, some of the problems faced by them are the extreme duty ratio, complex design and discontinuous input current. This paper presents a novel topology that uses an interleaved input, a voltage lift capacitor and a hybrid switched capacitor network to achieve high gain without an extreme duty ratio or bulky magnetics. The proposed converter is controlled using a microcontroller which regulates the output voltage. The voltage lift capacitor and the switched capacitor network enhances the voltage gain over a conventional... [more]

Phase change material (PCM) has received significant attention due to its great potential for thermal energy storage. However, the major undesirable property of PCM is related to its low thermal conductivity. In this work, the electrohydrodynamic (EHD) enhancement of PCM melting in circular-elliptical annuli is investigated numerically by using the lattice Boltzmann method (LBM). The key motivation for our choice of the elliptical shape is due to the fact that the more curved elliptical surface corresponds to stronger charge injection strength, which may lead to stronger flow field, and the consequent increase of heat transfer rate. The influences of several non-dimensional parameters, including electric Rayleigh number T, thermal Rayleigh number (Ra) and the aspect ratio (AR) of the inner ellipse are investigated in detail. Based on the numerical results, it is found that the radial electro-convective flow induced by the external electric field makes a significant contribution to the... [more]

Face and neck cooling has been found effective in improving thermal comfort during exercise in the heat despite the fact that the surface area of human face and neck regions accounts for only 5.5% of the entire body. Presently very little documented research has been conducted to investigate cooling the face and neck only to improve indoor thermal comfort. In this study, two highly energy efficient wearable face and neck cooling fans were used to improve occupant thermal comfort in two warm indoor conditions (30 and 32 °C). Local skin temperatures and perceptual responses while using the two wearable cooling fans were examined and compared. Results showed that both cooling fans could significantly reduce local skin temperatures at the forehead, face and neck regions by up to 2.1 °C. Local thermal sensation votes at the face and neck were decreased by 0.82−1.21 scale unit at the two studied temperatures. Overall TSVs decreased by 1.03−1.14 and 1.34−1.66 scale units at 30 and 32 °C tempe... [more]

A CMOS active rectifier with digitally adaptive delay compensation for power efficiency improvement is presented in this work. The power transistors are turned on and turned off in advance under the control of the regenerated compensation signals, which are generated by the proposed compensation control circuit; therefore, the reverse current is eliminated, and the efficiency is increased. Simulation results in a standard 0.18 μm CMOS process show that the turn-on and turn-off delay of the rectifier is effectively compensated. The power efficiency is up to 90.6% when the proposed rectifier works at the operation frequency of 13.56 MHz.

In arid climates, almost half of the urban peak load of energy demand is used to supply cooling and air-conditioning in the summertime. The pressure placed on energy resources to satisfy inhabitants’ indoor comfort requirements is mounting due to accelerated urbanisation rates in developing countries and has led countries such as those in the GCC (Gulf Cooperation Council) to establish sustainable building codes to enhance their environmental performance. Using the extensive parametric energy simulations provided by DesignBuilder, this study addresses the potential of applying different GCC energy efficiency measures to reduce annual energy consumption and carbon emissions in a typical residential dwelling in the Kingdom of Bahrain. To do so, first, a base case validation simulation model was generated, followed by four design scenarios addressing the minimum requirements for Bahrain’s Energy Conservation Code, Abu Dhabi’s ESTIDAMA 1, Saudi Arabia’s code, and Kuwait’s building code. Th... [more]

Non-domestic buildings are frequently characterised as resistant to top-down low-carbon and energy-efficiency policy. Complex relationships amongst building stakeholders are often blamed. “Middle actors”—professionals situated between policymakers and building users—can use their agency and capacity to facilitate energy and carbon decision-making from the “middle-out”. We use semi-structured interviews with expert middle actors working with schools and commercial offices, firstly, to explore their experience of energy and low-carbon decision-making in buildings and, secondly, to reflect on the evolution of middle actors’ role within it. Our exploratory findings suggest that a situated sensitivity to organisational “pressure points” can enhance middle actors’ agency and capacity to catalyse change. We find shifts in the ecology of the “middle”, as the UK’s Net Zero and Environmental, Social and Governance (ESG) agendas pull in new middle actors (such as the financial community) and issu... [more]

In the frame of the pre-conceptual design activities of the DEMO work package DIV-1 “Divertor Cassette Design and Integration” of the EUROfusion program, a mock-up of the divertor outer vertical target (OVT) was built, mainly in order to: (i) demonstrate the technical feasibility of manufacturing procedures; (ii) verify the hydraulic design and its capability to ensure a uniform and proper cooling for the plasma facing units (PFUs) with an acceptable pressure drop; and (iii) experimentally validate the computational fluid-dynamic (CFD) model developed by the University of Palermo. In this context, a research campaign was jointly carried out by the University of Palermo and ENEA to experimentally and theoretically assess the hydraulic performances of the OVT mock-up, paying particular attention to the coolant distribution among the PFUs and the total pressure drop across the inlet and outlet sections of the mock-up. The paper presents the results of the steady-state hydraulic experiment... [more]

We present an easily accessible model for dispatch and expansion planning of the German multi-modal energy system from today until 2050. The model can be used with low efforts while comparing favorably with historic data and other studies of future developments. More specifically, the model is based on a linear programming partial equilibrium framework and uses a compact set of technologies to ease the comprehension for new modelers. It contains all equations and parameters needed, with the data sources and model assumptions documented in detail. All code and data are openly accessible and usable. The model can reproduce today’s energy mix and its CO2 emissions with deviations below 10%. The generated energy transition path, for an 80% CO2 reduction scenario until 2050, is consistent with leading studies on this topic. Our work thus summarizes the key insights of previous works and can serve as a validated and ready-to-use platform for other modelers to examine additional hypotheses.

We extend the widely-studied Heterogeneous Autoregressive Realized Volatility (HAR-RV) model to examine the out-of-sample forecasting value of climate-risk factors for the realized volatility of movements of the prices of crude oil, heating oil, and natural gas. The climate-risk factors have been constructed in recent literature using techniques of computational linguistics, and consist of daily proxies of physical (natural disasters and global warming) and transition (U.S. climate policy and international summits) risks involving the climate. We find that climate-risk factors contribute to out-of-sample forecasting performance mainly at a monthly and, in some cases, also at a weekly forecast horizon. We demonstrate that our main finding is robust to various modifications of our forecasting experiment, and to using three different popular shrinkage estimators to estimate the extended HAR-RV model. We also study longer forecast horizons of up to three months, and we account for the poss... [more]