Level Of Energy Efficiency Research Articles

The HVAC model predictive control of building thermal dynamic characteristics

As the terminal energy user of urban power grid, it is significant to model and simulate the energy consumption characteristics of buildings. First, the author proposes a thermal dynamic model to predict the energy consumption of building refrigeration/heating, it is composed of several groups of heat transient energy balance equations, which can fully consider the impact of heat convection, heat conduction and heat storage on building energy consumption during the heat transfer process of building envelope. Then, the HVAC model predictive control (MPC) method considering the thermal dynamic characteristics of the building envelope is proposed for the heating, ventilation and air conditioning, the core energy unit of the building, the change of window wall ratio in building will affect the thermal insulation performance of the building, so the window wall ratio in building design should not exceed 0.7. From the perspective of building thermal insulation performance, the author analyzes the situation that the total 48 hours operating cost of buildings under two control methods changes due to the change of building thermal insulation performance with the change of window wall ratio in different environments, the simulation results show that when using MPC control method for HVAC, the daily operating cost of buildings increases with the window wall ratio at a lower rate than the traditional control method. It can be seen that the MPC control method has a better effect of energy saving and reducing the total operating cost of buildings in response to the environment where the window wall ratio of buildings increases or the thermal insulation performance of buildings becomes worse over time. It is proved that the HVAC control method based on MPC not only helps to reduce the building energy cost, but also deals with the reduction of HVAC energy efficiency level and the deterioration of building insulation performance, it is more conducive to saving energy and improving the operating economy of buildings.

Nonlinear programming for fleet deployment, voyage planning and speed optimization in sustainable liner shipping

<abstract> <p>Limiting carbon dioxide emissions is one of the main concerns of green shipping. As an important carbon intensity indicator, the Energy Efficiency Operational Index (EEOI) represents the energy efficiency level of each ship and can be used to guide the operations of ship fleets for liner companies. Few studies have investigated an integrated optimization problem of fleet deployment, voyage planning and speed optimization with consideration of the influences of sailing speed, displacement and voyage option on fuel consumption. To fill this research gap, this study formulates a nonlinear mixed-integer programming model capturing all these elements and subsequently proposes a tailored exact algorithm for this problem. Extensive numerical experiments are conducted to show the efficiency of the proposed algorithm. The largest numerical experiment, with 7 ship routes and 32 legs, can be solved to optimality in four minutes. Moreover, managerial insights are obtained according to sensitivity analyses with crucial parameters, including the weighting factor, unit price of fuel, Suez Canal toll fee per ship, weekly fixed operating cost and cargo load in each leg.</p> </abstract>

ENHANCED DESIGN AND DEVELOPMENT SIMULATION AND TESTING

Enhanced design and development simulation and testing using digital twins represent a significant advancement in the field of renewable energy systems. Digital twins, which are virtual replicas of physical assets, allow for comprehensive simulation and testing of various scenarios and new technologies within a virtual environment. This approach offers numerous benefits, including the ability to optimize designs, predict performance, and troubleshoot potential issues before actual deployment. By leveraging high-fidelity models and real-time data, digital twins provide an invaluable tool for improving the efficiency, reliability, and sustainability of renewable energy systems. The use of digital twins in renewable energy extends across different stages of the project lifecycle. During the design phase, engineers can test multiple configurations and materials, ensuring that the final design meets all performance and durability requirements. This reduces the need for physical prototypes, saving both time and costs. In the development phase, digital twins enable the simulation of operational conditions, helping to identify and mitigate risks early. For instance, they can model the impact of environmental factors such as wind, temperature, and load variations on wind turbines or solar panels. Once the systems are operational, digital twins continue to play a crucial role in maintenance and optimization. They provide continuous monitoring and diagnostics, predicting failures before they occur and suggesting maintenance schedules that minimize downtime. This proactive maintenance approach enhances the longevity and efficiency of renewable energy assets. Moreover, digital twins facilitate the integration of renewable energy systems with existing power grids, ensuring smooth and efficient operation. The implementation of digital twins also supports the testing of innovative technologies and strategies, such as energy storage solutions and smart grid applications, in a controlled, virtual environment. This capability is essential for advancing renewable energy technologies and achieving higher levels of sustainability and energy efficiency. As the renewable energy sector continues to evolve, digital twins will undoubtedly become an integral part of the design, development, and operational processes, driving innovation and improving the overall effectiveness of renewable energy systems. Digital twins offer a transformative approach to enhancing the design and development of renewable energy systems. By enabling detailed simulation and testing in a virtual environment, they provide significant advantages in terms of optimization, risk mitigation, and operational efficiency, ultimately contributing to the advancement of sustainable energy solutions. Keywords: Design Optimization, Stimulation, Digital Twin, Virtual Environment.

Analysis of Low-Density Heat Flux Data by the Wavelet Method

When evaluating the energy efficiency of buildings and implementing the necessary measures to increase energy efficiency levels, thermal technical characteristics are determined. For this purpose, in situ measurements of the thermal resistance of external enclosing structures were carried out. One of the methods most often used by researchers is the non-destructive method—the heat flow meter (HFM) method regulated by ISO 9869. In the case of surveying a building with a high level of thermal resistance, researchers are faced with low-density heat flux measurements, which is always a difficult task due to significant fluctuations and the influence of external factors on the measurement results. This is due to the fact that it is difficult to determine what is a useful signal and what is a consequence of the effects of non-stationarity and heat transfer conditions. The article provides an example of low-density heat flux measurements when determining the thermal resistance of a building and proposes a data pre-processing procedure that allows for the reduction of heat flux fluctuations, which has a significant impact on the final result at low density. The proposed use of wavelet analysis in the pre-processing of low-density heat flux measurement data makes it possible to reconstruct them or reduce disturbances that occur during research. A comparison of the obtained results with the results of the calculation according to ISO 9869-1 showed a decrease in the standard deviation of the measurements from 5.74 to 2.81%. The results of this study can be used to reduce the noise of low-density heat flux and, as a result, reduce the standard deviation of the measurement when applying the HFM method of determining the thermal resistance of external enclosing structures.

INVESTIGATION OF THE OPERATION MODES OF THE BELT-ROPE CONVEYOR ELECTROMECHANICAL SYSTEM WITH VECTOR-CONTROLLED INDUCTION ELECTRIC MOTORS

Continuous transport systems are the most promising type of movement of loose and artificial materials, have high productivity, technical and economic indicators and are widely used in world practice as main conveyors for the coal and mining industry. A special place in continuous transport is occupied by belt-rope conveyors, which are capable of transporting cargo over a distance of more than 30 km in one stop. As a rule, these main conveyors do not provide for the adjustment of movement parameters, the start is carried out using soft start systems. At the same time, such systems have high requirements for the parameters of dynamic modes of operation, the accuracy of working out the given movement program and the level of energy efficiency. The paper proposes a modern electric drive system using vector-controlled induction electric motors. The structure of the electromechanical system is given. A mathematical model of the electromechanical system was built using known methods. As part of the “MATLAB” Simulink application program package, a model for the investigation of dynamic modes of conveyor operation was obtained. On a specific example, a research of dynamic and static modes of conveyor operation with static load and the speed of movement variations of the traction element was carried out. Studies of the accuracy of working out the given law of motion showed that the maximum dynamic error in terms of speed and current is worked out in a time of up to 0.06 s. The maximum level of its amplitude does not exceed 0.33% of the constant speed of movement, which does not cause oscillatory processes in the conveyor and ensures stable operation of the electromechanical system. Investigation of the electromechanical system energy characteristics was conducted. Losses of active power do not exceed 12.5% of the consumed in the entire range of variation of the static load and speed of the traction element. Recommendations for the use of electromechanical systems with vector-controlled induction electric motors in belt-rope conveyors have been formulated.

GLOBALIZATION CHALLENGES TO UKRAINE’S ECONOMIC SECURITY AND POLICY PRIORITIES TO COUNTER THEM

Increased attention to the issue of ensuring Ukraine’s economic security in the conditions of the intensifying influence of globalization factors, challenges and threats. It is indicated that new globalization challenges determine the need for the formation of new tools and means of ensuring Ukraine’s economic security. The purpose of the study is to identify the globalization challenges to the economic security of Ukraine and justify the policy priorities for countering them. Main directions of the negative impact of globalization threats are determined and, based on them, strategic vectors of the state policy of ensuring the economic security of the national economy are identified. A complex of regulatory tasks and tools has been developed, which serve as guidelines for the formation of an effective and effective system for strengthening the economic security of Ukraine at the current stage of its socio-economic development. The priority areas of counteraction to globalization threats to the economic security of Ukraine are outlined, which define the diversification of foreign economic ties and relations, ensuring the stability of the functioning and independence of the financial system, improving the parameters of the social security system, engaging the “drivers” of economic development, strengthening energy independence and increasing the level of energy efficiency and energy saving , forming a system and ensuring a higher level of functional capacity of critical infrastructure elements, strengthening the functional and structural integration of spatial and territorial economic complexes. The applied value of the research results lies in the further development of the applied provisions of state policy strategizing to ensure the economic security of the state. The scientific novelty of the research results lies in the improvement and clarification of strategic priorities for strengthening the economic security of the state in the conditions of critically acute globalization risks, challenges and threats.

Methods of Enhancing Energy Efficiency at the Stage of Construction of High-Rise Residential Buildings

Introduction. People’s growing needs in energy resources in conditions of resource deposits depletion makes it relevant the development of methods of enhancing buildings energy efficiency. The article notes the importance of increasing the level of energy efficiency by selecting a set of measures for the efficient use of energy resources at all stages of the life cycle. The analysis of Rostov-on-Don housing stock and positive trend in housing commissioning capacity growth in Russia point at the need to enhance the energy efficiency of buildings being under construction.Materials and Methods. Energy efficient methods are as follows: the application of modern thermal insulation materials and "green" building technologies. The latter implies the approach to the design of buildings inferring minimized impact on the environment at all stages of the life cycle - from a building’s design to its elimination - including the application of "green" technologies: Smart Energy Glass windows, recuperators, solar panels.Results. The results of energy-efficient technologies application were considered on the example of “Ostrovsky” residential compound being under construction in Rostov-on-Don. As a result the planned energy efficiency class B (high) was upgraded to A + (very high), which corresponds to one of the green building criteria.Discussion and Conclusions. The use of energy efficient measures in construction of residential buildings allows to save considerable amounts of energy and resources at the stage of high-rise buildings operation, resulting in their energy efficiency class enhancement.

Multi-scale energy efficiency recognition and diagnosis scheme for ethylene production based on a hierarchical multi-indicator system

It is essential to monitor and diagnose the energy efficiency level of ethylene production process to detect any abnormities in the production and adjust production parameters appropriately to ensure the energy efficiency. However, few studies have been carried out concerning the diagnosis of abnormal energy efficiency in the ethylene production with appropriate energy efficiency indicator system from multiple dimensions due to the incompatibility of the diagnosis algorithm and the complexity of this petrochemical production. Therefore, to achieve a comprehensive energy efficiency diagnosis and anomaly analysis for the ethylene production, a multi-scale energy efficiency recognition and diagnosis scheme based on a hierarchical multi-indicator system is proposed. Firstly, a novel recognition scheme for abnormal energy efficiency is conducted from a single-indicator scale to a multi-indicator scale based on a three-level indicator system with respect to the energy and materials flows in the system, process, and equipment level of the ethylene production, so that the energy efficiency of the ethylene production can be monitored in different levels and granularities. Secondly, an integration-decomposition diagnosis method to analyze the energy efficiency is proposed based on the Malmquist production index, where the overall efficiency is decomposed into production efficiency, pure production technical efficiency, and scale efficiency to form a multi-perspective in-depth diagnosis and exploration. Thirdly, a principal component analysis is converted into a preliminary abnormal cause diagnosis algorithm based on statistics so that the multi-scale and multi-level energy efficiency recognition and diagnosis for the ethylene production is achieved. Finally, the effectiveness of the diagnosis scheme is verified by applying it to a Chinese ethylene plant, and the results show that the abnormal energy efficiency can be identified effectively and the consistency of the diagnosis results with the actual situation is approximately 0.818 at least.

Development of Ultra-High-Efficiency Medium-Capacity Chillers with Two-Stage Compression and Interstage Vapor Injection Technologies

Chillers are widely used in commercial buildings for air conditioning, and their energy consumption is the main contribution to the building’s carbon emissions. Currently, the COPs of small- and medium-capacity screw chillers are still generally lower than 6.5, whereas large-capacity commercial centrifugal chillers have achieved an ultra-high energy-efficiency level of COP ≥ 7.0. To achieve an ultra-high energy efficiency of COP ≥ 6.5 in medium-capacity chillers, the authors developed a 200 RT screw chiller by adopting the technologies of two-stage compression and interstage vapor injection. The whole development process, including the design, simulation, analysis, and experiment, is presented in this paper. It was found that the two-stage compression technology could effectively boost the performance of the chiller’s compressor to a maximum volumetric and adiabatic efficiency of 99% and 80%, respectively. With the interstage vapor injection technology, the chiller’s cooling capacity and COP were increased by more than 11% and 8%, respectively. When the use of these two technologies was combined, the maximum COP of the chiller reached 7.17. Additionally, under these working conditions, the COP and integrated part-load value (IPLV) were 6.74 and 10.04, respectively. In all, the combination use of vapor injection and two-stage compression technologies shows great potential to improve the performance of chillers. The work and conclusions described here might provide an effective reference for the future development of high-efficiency small- and medium-capacity screw chillers.

Analysis of environmental consequences occurring in the life cycle of a retail facility

The increasing importance of environmental protection issues has recently forced a low–emission approach to investment processes. To accomplish the European Union's climate, energy and environmental goals, action is needed to achieve high levels of energy efficiency and low environmental damage. Among the energy–intensive sectors, construction deserves a distinction due to its leading share in gross energy consumption in developed countries. Therefore, it is necessary, and at the same time more and more popular, to analyse the environmental loads generated in individual phases and throughout the life cycle of building objects. This subject is also gaining importance in the context of the recent increases in the prices of energy carriers, which forces the search for new construction and exploitation solutions in line with the philosophy of sustainable development and the circular economy. The aim of the analysis was to assess the environmental consequences in the life cycle of a real commercial building located in Janikowo (Kuyavian–Pomeranian Voivodeship), which was carried out using the LCA (Life Cycle Assessment) methodology. The obtained results indicated the dominance of the facility exploitation phase in the level of cumulative environmental loads.

Exploring the Role of Environmental Regulation and Fiscal Decentralization in Regional Energy Efficiency in the Context of Global Climate.

As an important factor of production, the use of energy will greatly improve production efficiency and is the material basis for China's sustainable development. Environmental regulation plays an important role in energy efficiency (EE), while fiscal decentralization is an important institutional context for China's economic development. In order to explore the role of environmental regulation and fiscal decentralization on EE, this paper measures the EE of 30 provincial regions in China from 2006 to 2020 by the super-efficient SBM method, and verifies the relationship between fiscal decentralization and environmental regulation on EE using a spatial econometric model, and conclusions as follows: (1) China's overall energy efficiency averages 0.563, still at a low level, with the highest average efficiency value in the east and the lowest in the west. (2) An inverted U-shaped relationship exists between environmental regulation and EE, and its spatial spillover effect also shows an inverted U-shaped relationship. Fiscal decentralization promotes the regional EE, and its spatial effect also significantly positive. (3) When the level of environmental regulation increases, the EE level of the local and neighboring provinces will increase. The enhancement of fiscal decentralization system can promote local EE, but it has a negative effect on the energy efficiency level of neighboring provinces. Finally, based on the results of the empirical analysis, this paper proposes suggestions for improving regional EE, which are of great theoretical and practical value for improving climate change and achieving sustainable regional economic development in China.

Improving Energy Efficiency in China Based on Qualitative Comparative Analysis

Currently, in China, the influence of energy efficiency problems on economic and social development is increasingly prominent. The factors influencing energy efficiency and improving them have become the focus of academics. In this study, the effects of allocation on technical progress, industrial structure, energy consumption structure, and economic levels of energy efficiency are discussed based on a sample of 30 provinces in China using qualitative comparative analysis (QCA). The results show that three paths could simulate high energy efficiency. The first path is dominated by economic level and energy consumption structure, with the assistance of industrial structure. The second path is dominated by economic level and energy consumption structure, with the assistance of technical progress. The third path is dominated by technical progress and industrial structure, with the assistance of economic level. None of the proposed four factors were required for high energy efficiency. Path 1 and path 2 formed the second-order equivalent configuration. In most provinces, high energy efficiency is stimulated through the path dominated by technical progress and industrial structure, assisted by economic level.

Energy-Aware Hierarchical Resource Management and Backhaul Traffic Optimization in Heterogeneous Cellular Networks

The dense deployment of small-cell networks is a key feature of the next-generation mobile networks employed to provide the necessary capacity increase. The small cells are installed in the areas covered by macro base stations (eNBs) to supply the required local capacity based on the known concept of the hierarchical HetNets. Moreover, small-cell networks use high-capacity backhaul links on millimeter-wave bands to develop multihop topologies to mitigate the costs of data transmission. Nonetheless, green networking gains great importance for the uncontrolled installation of too many small cells may escalate operational costs and emit more carbon dioxide. This article proposes a dynamic optimization model to minimize the overall energy consumption of fifth-generation (5G) heterogeneous networks and provide the essential coverage and capacity. Optimizing carrier allocation and power utilization, the proposed model determines when to turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> or <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> small cells to meet the quality of service constraints of users with the highest level of energy efficiency. We also proposed a multihop backhauling strategy to effectively use the existing infrastructure of small-cell networks for simultaneous dual-hop transmissions. The numerical results indicated considerable rates of power saving in different traffic models while guaranteeing the throughput requirements for uniform and hotspot user equipment distribution patterns. Also, according to the simulation results, energy efficiency and system data rates can significantly be improved.

Challenges of Energy Management in the Food Industry in Poland in the Context of the Objectives of the European Green Deal and the “Farm to Fork” Strategy

The Common Agricultural Policy defines the framework directions for the structural changes of the agri-food sector until 2030. The main reason for the actions is a fundamental change in the European Union’s approach to environmental protection issues and the dynamically changing conditions on the market for energy and agricultural raw materials. The European Green Deal, the key element of which is the “Farm to Fork” strategy, is the expression of the announced changes. The assumption of the documents is the long-term restructuring and modernization of the EU economy, which will be characterized, among others, by a closed cycle, low greenhouse gas emissions, and food and energy security. The challenges and the current situation in the markets of energy carriers are of significance in the activities of the food industry, which shows a high demand for energy. The aim of the article is to assess the level of consumption and energy efficiency of food industry enterprises in Poland, to identify challenges related to energy management and to formulate conclusions and recommendations in the field of changes adapting to the new conditions. The research results indicate that many positive changes took place in the energy economy of Polish food industry enterprises, among others, as a result of the implemented investments, the energy consumption of production, CO2 emissions and the amount of generated waste decreased. Due to unfavorable external conditions, it is necessary, however, to further improve the energy efficiency of enterprises, so that they can maintain cost competitiveness and meet the growing requirements in the field of environmental protection.

Assessment of environmental tax and green bonds impacts on energy efficiency in the European Union

Owing to the increased greenhouse gas emissions and threat of environmental pollution, scholars have drawn attention to the issue of energy efficiency in recent decades. One of the main practical policies related to energy efficiency is deploying green tax and green financing tools. The main purpose of this paper is to analyze the impacts of issued green bonds and environmental taxes on energy efficiency in the 27 European Union (EU) member states from 2010 to 2021. The major results confirm that green bonds accelerate the process of improvement of the level of energy efficiency in EU members. In the EU, environmental taxation is an efficient fiscal policy to encourage enterprises to conduct different policies and projects to improve their energy efficiency levels. In addition, a 1% increase in the gross domestic product leads to an increase in energy efficiency of the EU by nearly 0.39%. The recommended practical policies are promoting the green bond market through more transparency and marketing among private investors, paying attention to the concept of green economic recovery, and issuing digital green bonds (DGBs).

ДОСЛІДЖЕННЯ РІВНІВ ЕНЕРГОЕФЕКТИВНОСТІ ВУГІЛЬНИХ ШАХТ.

The purpose of the article is the formation of the principles of determining the best practice of energy consumption efficiency among coal mines, which will take into account the initial conditions of their operation. The study is devoted to the development of the issue of organization of assessment of energy efficiency levels of coal mines. One of the main components of increasing the level of energy efficiency assessment of coal mines is the implementation of actions regarding the use and implementation of adequate assessment of the level of their energy use and the state of energy conservation. For this, it is necessary to apply such an evaluation mechanism that would allow evaluation and analysis of indicators that have an unequal impact on the efficiency of energy use. It is relevant in this direction to define universal rules for conducting assessment activities, which cover all key areas of monitoring the level of energy efficiency using the ranking of objects. The result of the ranking is a certain number of ratings, which are used to assess the level of energy efficiency. Therefore, for research purposes, a procedure for evaluating the energy efficiency of coal mines is proposed, which is based on a multivariate comparison with the application of ranking according to the Condorcet’s rule. This procedure involves taking into account the technological process and operating conditions of the coal mine. The ranks of coal mines were determined according to their energy efficiency. Specific electricity consumption, coal output and production were used as evaluation criteria. It is shown that the ranking procedure according to the Condorcet’s rule makes it possible to determine the best and worst coal mines in terms of energy efficiency. The use of the proposed procedure ensures the reliability of management actions aimed at increasing the level of energy efficiency of the energy consumption system of coal mines.

Behavioral Barriers to Energy Efficiency and Policy Interventions: A Survey of the Literature

The increasing energy demand implying the depletion of fossil fuels and a worsening of poverty, and the alarming level of pollution leading to an unprecedented climate urgency, call for a rapid reduction of energy consumption. Despite the global recognition of the compelling benefits of energy efficiency, there is still a gap between the theoretical potential and the current level of energy efficiency. Agents’ irrational hesitation to invest in energy efficiency explains a significant proportion of the energy efficiency gap. Behavioral barriers have caused policymakers to question the relevance of traditional information-based instruments. To address behavioral obstacles, a reconsideration of traditional policies appears to be necessary. We examine the key barriers related to agents’ behavior and how they reinforce each other. Then we suggest that policies should consider nudging strategies, which offer valuable insights regarding the human decision-making, and which represent a pivotal way to close the energy efficiency gap.

Strategic planning in energy saving at industrial enterprises of Russia

Our country has been and remains one of the leaders in the world's energy industry. Russia's energy needs are fully met by its own resources. Annual export volume of mineral fuel, oil and petroleum products is about 600700 million tons in conventional terms. Currently, the situation with exports is complicated by sanctions and the geopolitical situation in Russia and in the world. Only taking into account the embargo imposed by the U.S., Britain, Australia and Canada, export losses are more than 40 million tons. In addition, Russia is the world leader in proven reserves of natural gas, its volume more than 50 billion cubic meters. At the same time, it should be noted that such high indicators and sufficient resource potential are present at an extremely low level of energy efficiency. Thus, the volume of energy costs for the production of the average Russian producer is about twice as much as the global average. On this basis, the need to improve the quality of strategic planning and to promote targeted activities in the field of energy conservation in industry in the Russian Federation becomes obvious. Such activities will have not only positive economic, but also social, political, environmental and other types of effects. The most energy-consuming branch of industry in Russia is the processing industry, which is about 30 % of all final energy consumption. Another 70% of the energy saving potential is represented by metallurgy, chemical and oil refining and other industries.

Prefabricated structures of buildings from steel thin-wall cold formed profiles Cocoon "Transformer"

Cocoon System AG's light steel thin-walled structures have proven their worth in numerous superstructures, extensions, exterior wall and ceiling systems, as well as complex projects by internationally renowned architects. As part of the implementation and development of lightweight construction methods, this company has developed the Cocoon "Transformer" system, represented by prefabricated wall and floor structures with varying degrees of completeness and enlargement, registered as ETA - 11/0105. The Cocoon "Transformer" system is a frame-sheathing self-supporting or load-bearing, external or internal structure, the components of which are steel thin-walled cold-formed profiles, plate materials (cladding), insulating materials and fasteners. ETA-11/0105 suggests an optimization of this structural system. The European project ELISSA was created to improve the construction of walls, floors, roofs and volumetric modules of the Cocoon "Transformer" system with improved thermal, acoustic, vibration / seismic and fire resistance characteristics, as well as to develop industrially safe methods for their application. The use of high-performance airgel thermal insulation strips in this project minimized the effect of thermal bridging in the exterior wall structure and brought the heat transfer coefficient closer to the requirements of a passive house. The new prefabricated lightweight elements ELISSA, which demonstrate a high level of energy efficiency, provide the possibility of using insulated vacuum panels (VIP) with increased strength. The increased strength of Super Insulated VIP Panels is due to the use of foils with better endurance and also encapsulated in polyurethane. However, the version of the ELISSA system using VIP panels significantly increases the cost of the wall structure, which may hinder its widespread use in Ukraine. The creation of standard economic solutions with a sufficient level of energy efficiency according to the Cocoon "Transformer" construction concept will allow, to a certain extent, to reduce the costs of restoring the housing stock of Ukraine, damaged as a result of hostilities, and solve the problem of rapid new construction to replace completely destroyed housing.

The fuel and energy complex system of Ukraine: established approaches and structure

The energy potential of Ukraine under wartime conditions has been clarified. The work of scientists, researchers, and practitioners regarding the goals and strategies of developing the fuel and energy potential system is analyzed. The main approaches to its formation and structure are outlined. Significant flaws in the organizational and territorial significance of the fuel and energy complex of Ukraine are outlined. It became known that the energy and hydropower industries lagged the main branches of fuel and energy resources relative to the broad scale of the increase in energy consumption. This, in turn, provoked a shortage of coal mass consumption at the state's electric and thermal capacities. It was determined that after the collapse of the USSR, in Ukraine, the energy system occupied the first place in the state's economy. Its priority was the satisfaction of the potential of the domestic energy demand, as well as exports to the countries of the European Union. This process supplies primary energy resources, including oil products, natural gas, oil, and nuclear fuel. At the same time, Ukraine somehow failed to form an adequate basis for the implementation of energy policy with the aim of stable and balanced development of the energy sector and the formation of a system of energy independence from foreign suppliers. It is no secret that the energy industry of Ukraine became the leading supplier of energy raw materials for other countries. As a result of the analysis of indicators regarding the income of companies in various industries, it can be stated that in 2021, the Ukrainian economy will remain raw-based and will continue. Even though the solution to the problems of the existence of the fuel and energy complex of Ukraine is aimed at achieving national goals, at the same time, there are minor problems. Therefore, in our opinion, the short-term and long-term stages of its implementation should be considered when developing an appropriate strategy. As for the effectiveness of the mentioned strategy, it is worth justifying the necessary conceptual and conceptual toolkit and the methodological directions for further generalization. Taking into account the content of the Energy Strategy of Ukraine until 2035, "Security, energy efficiency, competitiveness," we believe it is worth developing appropriate types of energy strategies regarding increasing the level of energy efficiency, strengthening the norms and principles of energy security. Keywords: fuel, energy, complex, structure of the energy complex, fuel crisis, energy strategies, combined gas transportation system, electric power enterprises, energy conservation policy, fuel, and energy sector, hydropower, nuclear power, renewable energy sources