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Abstract The coordinated development of intelligence and greening is an intrinsic demand for high-quality economic and social development. Intelligentization and greening are the leading directions of sustainable development of the power industry. This paper directs of sustainable development of the power industry. This paper empirically analyzes the effect and mechanism of intelligence on the green environmental friendliness of electric power substations by using a panel fixed-effects model and instrumental variable regression, using substation engineering data from China southern power grid during 2013–2022. It is found that the level of intelligence significantly promotes the green performance of substation projects, and this conclusion still holds after a series of robustness tests. Intelligence can reduce material waste and pollutant emissions by improving the engineering environmental monitoring capability and the refinement of engineering resource control, thus improving the environmental friendliness of the project. The research in this paper helps to promote the integrated development of intelligent and green power engineering, to better achieve economic and green goals.

To reach the climate goals set by national and international institutions, a vast transition of the legacy power system is unavoidable. The necessary integration of distributed, renewable generation devices, which are often interfaced with power electronic converters, has a non-negligible influence on the characteristics of the power grid. This is particularly visible during abnormal grid conditions such as faults. For rotating machines, the fast-timescale reaction to these events is mainly determined by physical properties. However, power electronic devices lack this strong coupling and their behavior is generated by the control and automation system, making them a major field of interest during this transition. The present paper provides a survey of real-world incidents, as for example blackouts or oscillatory incidents, that are discussed with respect to the implications for future converter dominated power grids. For typical cascading outages it is shown, where the increasing penetration of distributed, renewable generation and smart grid technologies can be leveraged to increase the system resilience, e.g. by providing grid services through adequate control design or by enabling microgrid concepts. Further, real-world examples of newly emerging challenges driven by power electronic devices are presented. The mechanisms of control system interactions with the neighboring grid and its inherent complex dependency on various factors is illustrated. Lastly, resulting structural developments such as the changed resonance properties of low voltage grids and the increase of harmonic emissions are exemplified.

Hydrogen energy has an advantage over conventional fossil energy because of its clean and low-carbon features, while its stability gives it an advantage over renewable energy sources such as hydropower, photovoltaic (PV) power, and wind power. Using hydrogen as a fuel can achieve zero carbon emissions or even net zero emissions at the end of energy conversion. Moreover, with hydrogen as the carrier, an energy system of multi-energy complementarity will be established by coupling multiple energy systems such as power grids, gas grids and heat networks, which can realize the comprehensive utilization of renewable energy sources in an efficient, stable, and flexible manner. Based on the “dual carbon” goals, this paper targets sectors with high carbon emissions represented by electric power, steel and transportation, analyzes the feasible path of using hydrogen energy to promote deep carbon reduction, and points out the obstacles faced by hydrogen energy development in various sectors. On account of the current development and expected prospects, this paper proposes that the current focus of hydrogen energy industry is to coordinate the development of industrial sectors and regions, build a pattern that can facilitate the industry’s systematic and concerted development, address key technical challenges (such as green hydrogen production or hydrogen storage and transportation via pipeline), improve industrial standards, and promote the industry’s development in a balanced, coordinated and orderly way.

The aim of this article is to present solutions related to wind energy in EU countries as an alternative to fossil fuels. This article is based on secondary information and statistical data regarding the development of wind power engineering in EU countries for the years 2016–2022. The main purpose of this paper is to analyze of the relations between the development of wind energy in European Union countries and GPD (gross domestic product) per capita and selected factors. The following hypotheses were formulated: H1—There is a statistically significant correlation between GDP per capita and the use of wind energy in European Union countries. H2—There is a relationship between the length of the coastline and the use of wind energy in European Union countries. H3—There is a statistically significant correlation between the attitude to uncertainty of the inhabitants of a given country and the use of wind energy in said country. The presented research results support all these hypotheses. The results of the research regarding H2 are as follows: in the case of northern European countries (Ireland and Finland) and the Iberian Peninsula (Spain and Portugal), the development of wind power engineering in the study period was faster than could be inferred from the length of the coastline in these countries. Regarding hypothesis H1, it was concluded on the basis of the analysis that the involvement of countries in the development of wind power engineering is correlated with their wealth. The novelty of this paper emerges from its innovative approach to analyzing wind power engineering, its incorporation of cultural factors, its quantitative assessment of correlations, and its actionable policy recommendations. These elements collectively contribute to a comprehensive and impactful study that advances our understanding of wind energy adoption in the European Union.

In order to promote the construction of a clean, low-carbon, and diversified modern rural new energy system, this study examines the development, utilization, connection, and system construction of rural new energy in China. This is done through the classification, integration, and systematic analysis of official statistical data and materials from recent years. Utilizing descriptive statistical analysis, the study holds great theoretical and practical significance. The findings indicate the following: 1) overall, the development of new energy in China’s rural areas is progressing well. However, there is an increasing contradiction between supply and consumption. 2) The new energy industry is experiencing overall growth, accompanied by increasing policy support. Despite this, the industry’s driving effect is not substantial. 3) The development of new energy production equipment in rural areas is lagging, resulting in insufficient cleanliness of energy consumption. There is still a significant gap compared to the goal requirements of agricultural and rural modernization. 4) During the process of rural new energy connection and development, there exists a lack of strong connections between the various subjects of interest. The interest relationship is consequently unstable, necessitating the improvement of a closely-knit interest community. Taking the issue of rural new energy development as its starting point, this paper thoroughly explores the mechanisms driving rural new energy connection. It delves into the interest relationship between the different stakeholders and provides guidelines for optimizing rural new energy system construction. Ultimately, this research aims to contribute to rural revitalization, facilitate the realization of the “double carbon” goal, and establish a modern rural new energy system.

The transformation of the European energy sector is becoming a priority for the European Union. This is indicated, for instance, in the European Union strategy known as the European Green Deal. According to the Green Deal, the area of ‘research and innovation’ is one which can counteract climate change. Universities can play a significant role in this by adopting a pedagogical approach aimed at mobilizing the spirit of innovation and entrepreneurship in young professionals. In addition to modifying curricula related to mining, energy, and environmental engineering, i.e., activities in recognized, traditional schemes, one prospective tool may be the involvement of students and PhD candidates in European initiatives such as the InnoEnergy PhD School (which is funded by the European Institute of Innovation and Technology). This paper aims to discuss the InnoEnergy PhD School programme as a possible instrument for mitigating the negative effects of energy transformation. The article analyzes the programme using a case study method, including surveys and open interviews. The paper draws attention to and highlights the role of human resources in the field of education and the stimulation of innovation, as well as the need to strengthen the business component in the education of PhD candidates.

The article, meant as the first in a series, tries to answer some questions around the future desired shape of the new Polish electro-energy mix in relation to the one described in the national energy policy document PEP 2040 (Energy Policy of Poland till 2040) and as compared with the targets set up in the newest UE legislative package, ‘Fit-for-55’. In this article, I first present the rich overview of literature as well as economic theory behind the analysis of the energy transformation and energy-mix decarbonisation, in order to show how the energy mix should evolve in a way that will guarantee the biggest net gain to the society. Second, some comparable cost calculations on selected electro-energy sources, both LCOE (levelized cost of energy) and external costs are presented; these are modifications of my previous work as a co-author. Finally, the comparison of the 2040 electro-energy mix, as designed in the official governmental programme PEP 2040, with the two alternative scenarios, both of which exclude coal, and one also neglects the possibilities for nuclear energy to be included in the mix are presented. The alternative scenarios built into the paper are based on European Union (EU) plans to decarbonise Europe quickly. Recent geopolitical considerations related to the war in Ukraine, however, make it necessary to consider energy security as an important part of the plan. That would mean that nuclear energy would be a necessary component of the future mix in Poland. Security considerations are left to be analysed in the coming months, after a series of articles on lessons learnt by other developed countries in the process of making their energy-mix transformations and will complete the final recommendations for the future of the Polish energy mix.

The main aim of this paper was to determine changes in renewable energy production in the countries of Central and Eastern Europe. The specific objectives were to assess the degree of concentration of renewable energy and the pace of changes in the volume of production of this energy from individual sources in the countries of Central and Eastern Europe, as well as to determine the structure according to renewable energy sources to show the directions of changes. Central and Eastern Europe countries were covered in the research, meaning that a total of 23 countries were included in the analysis. The data used in the study was obtained from the IRENA and World Bank databases. The research period covered the years from 2011 to 2019. For data analysis, the following methods were used: Index methods, Gini coefficient, Lorenz curve, and Grade Data Analysis. The development of the renewable energy sector and modernisation of the energy structure are of great importance for countries to meet their climate obligations. Large-scale energy production from renewable sources could reduce a 60% reduction in the temperature rise. Additionally, such activities will contribute to an increase in energy efficiency by 90%. The energy transition would also bring more comprehensive social and environmental benefits. Thus far, researchers have dealt with energy consumption-related problems in Central and Eastern Europe countries. This article focuses on the production of renewable energy in countries of Central and Eastern Europe. The article fills the research gap in this area. It refers to the situation in the countries of Central and Eastern Europe at a time when developing renewable energy has become very important. In our analysis, we examine renewable energy production in countries located in one region but are and are not EU members. Thanks to this, it will be possible to observe differences in terms of belonging to economic groups. In the case of the pace of changes and the structure of renewable energy produced, a difference can be found between the EU member countries of Central and Eastern Europe and the group of countries outside the EU. The fastest renewable energy production growth was achieved in EU member countries of Central and Eastern Europe. In the case of the mentioned countries, the production of solar, wind, and bioenergy was developed. In other countries, hydropower production was set and treated as a traditional energy source. Generally, in countries of Central and Eastern Europe, the development of energy based on renewable energy sources was not dependent on the pace of economic development of the country. Decision-makers in the countries of Central and Eastern Europe should develop the production of renewable energy from sources that are the easiest and cheapest to use. This is the only way to increase the production of renewable energy in developing countries.

The Wulingtou tunnel in Xuancheng City is faced with complex geological conditions in the construction process, and the construction is difficult. The research team of Anhui University of Science and Technology applied the new sprayed engineered cementitious composites (NS-ECC) to the initial support structure of K43 + 546.3-K43 + 556.7 section of the tunnel. The mechanical properties of NS-ECC were significantly improved compared with that of single fiber (1% volume content), and the compressive strength is ‘positive hybrid effect’. In this paper, the ordinary C25 sprayed concrete (SC-C25) was compared with NS-ECC to precisely evaluate their performance. Slump and rebound rate tests and uniaxial compression tests under four water-containing states and five loading rates were carried out, and the differences in performance were studied in detail via scanning electron microscope and nuclear magnetic resonance tests and based on energy evolution and transformation characteristics. Results show that the real water absorption and rebound rate of SC-C25 were significantly higher than those of NS-ECC. Increasing the water content reduced the compressive strength, peak strain and energy storage density of both cements yet increased their elastic modulus. In the saturated water state, increasing the loading rate also increased the compressive strength, elastic modulus and energy storage density limit values of both cements yet decreased their peak strain. NS-ECC reported higher strength, peak strain, energy storage density and sensitivity to the ‘Strain rate effect’, under the saturated state, its peak stress is 32.92 MPa, peak strain is 0.65%, the energy storage density limit is 0.01MJ/m3, and the elastic energy conversion rate reaches 95.9%, which are better than SC-C25.

Currently, hydrogen and electric drives used in various means of transport is a leading topic in many respects. This article discusses the most important aspects of the operation of vehicles with electric drives (passenger cars) and hydrogen drives. In both cases, the official reason for using both drives is the possibility of independence from fossil fuel supplies, especially oil. The desire for independence is mainly dictated by political considerations. This article discusses the acquisition of basic raw materials for the construction of lithium-ion batteries in electric cars, as well as methods for obtaining hydrogen as a fuel. The widespread use of electric passenger cars requires the construction of a network of charging stations. This article shows that, taking into account the entire production process of electric cars, including lithium-ion batteries, the argument that they are ecological cannot be used. Additionally, it was indicated that there is no concept for the use of used accumulator batteries. If hydrogen drives are used in trains, there is no need to build the traction network infrastructure and then continuously monitor its technical condition and perform the necessary repairs. Of course, the necessary hydrogen tanks must be built, but there must be similar tanks to store oil for diesel locomotives. This paper also deals with other possibilities of hydrogen application for transformational usage, e.g., the use of combustion engines driven with liquid hydrogen. Unfortunately, an optimistic approach to this issue does not allow for a critical view of the whole matter. In public discussion, there is no room for scientific arguments and emotions to dominate.

Algeria heavily relies on fossil fuels, particularly oil and gas, leading to inadequate energy supply in rural areas. However, the country possesses vast agricultural land and abundant renewable energy resources like solar and wind. Due to the insufficient national electricity grid, rural farmers must resort to expensive and environmentally unfriendly diesel generators to meet their energy needs. To address this issue, decentralised energy systems are proposed as a solution to enhance energy resilience on Algerian farms. These systems can power irrigation pumps, lighting, and other electrical appliances on the farm. Furthermore, surplus energy generated by the PV systems can be sold back to the grid or used to offer paid energy services, creating a new revenue stream for farmers. This study evaluates the potential opportunities for implementing Decentralized and Distributed Renewable Energy Systems (DRES) on farms in Algeria. It will review current policies and regulations for microgrids in the country and present various scenarios for bottom-up energy transformation. This paper will identify the challenges and barriers Algerian farms face in energy, water, and agriculture practices. The findings will demonstrate how DRES can improve energy efficiency, reduce costs, increase the share of renewable energy, and enhance electricity supply reliability in Algeria. The study will provide practical guidance to policymakers and identify opportunities for integrating DRES on farms while suggesting future research directions in sustainable energy.

Hydrogen can be considered an innovative fuel that will revolutionize the energy sector and enable even more complete use of the potential of renewable sources. The aim of the paper is to present the challenges faced by companies and economies that will produce and use hydrogen. Thanks to the use of hydrogen in the energy, transport and construction sectors, it will be possible to achieve climate neutrality by 2050. By 2050, global demand for hydrogen will increase to 614 million metric tons a year, and thanks to the use of hydrogen in energy, transport and construction, it will be possible to achieve climate neutrality. Depending on the method of hydrogen production, the processes used and the final effects, several groups can be distinguished, marked with different colors. It is in this area of obtaining friendly hydrogen that innovative possibilities for its production open up. The costs of hydrogen production are also affected by network fees, national tax systems, availability and prices of carbon capture, utilization, and storage installations, energy consumption rates by electrolyzers and transport methods. It is planned that 1 kg of hydrogen will cost USD 1. The study used the desk research method, which made it possible to analyze a huge amount of descriptive data and numerical data.

One of the ways to improve the performance of centrifugal pumps, proposed and experimentally validated by our research, is the method of creating so-called coherent structures, vortices and turbulence in the peripheral area of the centrifugal stage by adding a vortex rim to the back side of centrifugal rotor. A new construction of the pump, so called centrifugal vortex pump (CV), combines the good sides of these two types of pumps: high head of the vortex pump and high efficiency of the centrifugal pump. In addition, centrifugal pumps deliver higher flow rates with lower pressures, vortex pumps deliver higher pressures but with lower flow rates. For centrifugal vortex pumps, the vortex blades are located at the rear of the centrifugal rotor. The outer diameter of the vortex rim (VR) is smaller than the outer diameter of the centrifugal rotor (CR). The vortex rim induces vorticity to a portion of the flow that has passed through the centrifugal rotor. This vortexed flow is then reunited with the rest of the flow that has not been pulled down by vortex rotor. The vortex energy of that additional stream transfers some of its kinetic energy to the main stream. This added kinetic energy is converted to a pressure that accumulates the pressure exerted by the centrifugal rotor, and thus the vortex rim improves the overall pump performance. An intense process of gas dispersion occurs in the vortex region, which increases the stability of the pump when pumping a mixture of liquids and gases. The process of energy conversion in a centrifugal vortex pump, i.e., flow visualisation of mixing streams from a centrifugal rotor and a vortex rotor, and the quantization and superpositions have been shown in this paper.

The paper deals with the peculiarities of thermodynamic analysis of technological systems of food production with generation of secondary steam. System analysis is based on information about production, equipment operation, modern scientific achievements and modeling methods in chemical, physical, mathematical and other sciences. The information about applied energy and thermodynamic criteria, criteria of optimization of systems, list of sequence of actions on improvement of systems is given. Secondary energy resources of food industries are often represented by thermal energy of liquid media or secondary steam. Regeneration of the secondary steam allows, during its subsequent condensation, to return the heat potential of the steam to the media. This means that in the systems where the increase in the thermodynamic parameters of steam due to its compression, there is the use of Carno's return cycle. Such use occurs both in closed and open cycles. The description of the physical processes accompanying the work of the thermocompressors is subject to mathematical modeling based on the laws of conservation of energy, mass conservation and conservation of impulses. The assessment of the suitability for using secondary energy resources is based on exergy methods in order to determine the directions for their further improvement. For identical pressures in the mixing chamber, the efficiency of the actual compressor is higher than the ratio of the ejection coefficients of the real and ideal compressors, since internal irreversible losses along with the reduction of the ejection rate result in the increase of the specific exergy of the compressed flow.

Employment and the competencies of employees in the energy sector are coming into particular prominence in economies around the world. It is one of the few sectors positively affected by the COVID-19 pandemic. As a result, a significant global change in the awareness of society occurred in favor of increasing pro-health and pro-environmental activities, which can be seen in the green transformation. Poland can also boast such changes in recent years, as evidenced by the dynamic development of renewable energy sources (boom for photovoltaics) and the increase in prosumption. Correlated with this is the increase in demand for employees with specific competencies, the so-called multi-competencies that are a compilation of technical, business, and soft and hard competencies, as well as interdisciplinary ones. The paper emphasizes the need to better adjust the education system to the real needs of the labor market in a turbulent environment with the use of the Sectoral Qualifications Framework in Energy, developed in cooperation with stakeholders from the industry. Therefore, the authors analyzed the employment structure in the energy sector in Poland, with particular emphasis on the factors and conditions of this structure and made an attempt to identify and create a competency profile of employees in this area. For the purposes of this article, two key research problems were formulated: What are the key competencies of employees in the energy sector? How is employment changing in this area? The following research hypothesis was also put forward: The transformation of the energy sector towards green energy affects the increase in employment in this area and the increase in the demand for soft competencies. The analysis was based on statistical data, reports, job advertisements, and a review of the results of empirical research to date.

Fully decarbonising global power supply is essential to meet the objectives of the Paris Agreement. A wide range of inter- and transnational governance institutions exist that work towards the transformation of the power sector. But are these governance efforts sufficient to address the challenges? To address this question the article first identifies governance needs on the basis of systemic sector-specific transformation challenges and discusses the potential for international governance to address them. Second, the paper surveys existing inter- and transnational institutions and assess to what extent they exploit the potential of international governance. The analysis shows that many of the governance needs are already being satisfied to some extent, particularly with respect to the deployment of renewable energy. It also shows that a significant blind spot remains: the phase-out of fossil fuels for electricity generation. The detailed analysis enables us to identify options for enhancing the governance landscape.

Like many other countries, Germany has defined goals to reduce its CO2-emissions following the Paris Agreement of the 21st Conference of the Parties (COP). The first successes in decarbonizing the electricity sector were already achieved under the German Energiewende. However, further steps in this direction, also concerning the heat and transport sectors, have stalled. This paper describes three possible pathways for the transformation of the German energy system until 2050. The scenarios take into account current climate politics on a global, European, and German level and also include different demand projections, technological trends and resource prices. The model includes the sectors power, heat, and transportation and works on a Federal State level. For the analysis, the linear cost-optimizing Global Energy System Model (GENeSYS-MOD) is used to calculate the cost-efficient paths and technology mixes. We find that a reduction of CO2 of more than 80% in the less ambitious scenario can be welfare enhancing compared to a scenario without any climate mitigating policies. Even higher decarbonization rates of 95% are feasible and needed to comply with international climate targets, yet related to high effort in transforming the subsector of process heat. The different pathways depicted in this paper render chances and risks of transforming the German energy system under various external influences.

The presented paper shows a hypothetical large solar farm that would be the only source of electricity for the entire country. The energy crisis in Europe raises the question of whether it is possible to supply an electrical system based only on renewable energy sources. What should the surface area of the solar panels be in a hypothetical large solar farm to power the entire country? In this work, we will show what requirements must be met to make this feasible. Very important differences between the installed power capacity in a coal-fired or nuclear power plant and a solar power plant are discussed. The article presents calculations of the surface area of photovoltaic panels in that solar farm for four exemplary countries in Central Europe: Poland, Germany, the Czech Republic and the Slovak Republic. These studies are particularly important for Poland, whose electrical system is still mainly based on coal-fired power plants. The hypothetical solar farm could, in practice, take the form of dozens of solar power plants located in different parts of the country. Most importantly, the proposed solution will counteract climate change.

With an increasing expected energy demand and current dominance of coal electrification, India plays a major role in global carbon policies and the future low-carbon transformation. This paper explores three energy pathways for India until 2050 by applying the linear, cost-minimizing, global energy system model (GENeSYS-MOD). The benchmark scenario “limited emissions only„ (LEO) is based on ambitious targets set out by the Paris Agreement. A more conservative “business as usual„ (BAU) scenario is sketched out along the lines of the New Policies scenario from the International Energy Agency (IEA). On the more ambitious side, we explore the potential implications of supplying the Indian economy entirely with renewable energies with the “100% renewable energy sources„ (100% RES) scenario. Overall, our results suggest that a transformation process towards a low-carbon energy system in the power, heat, and transportation sectors until 2050 is technically feasible. Solar power is likely to establish itself as the key energy source by 2050 in all scenarios, given the model’s underlying emission limits and technical parameters. The paper concludes with an analysis of potential social, economic and political barriers to be overcome for the needed Indian low-carbon transformation.

Establishing conditions that meet climate requirements should be one of the most important goals of the whole world in order to protect against the negative effects of climate change. Without cooperation and considerable commitment from everyone, it is possible that these negative effects will worsen. The implementation of the Energy Policy from now until 2050 should facilitate the transformation of the coal-based power system toward a more sustainable and diversified mix of energy sources. Financial investments in the countries analyzed in this paper create real opportunities and changes for the transition toward renewable energy sources (RES), but there is criticism concerning the insufficient speed of change and the costs of the transformation for society. The dominant emphasis on the optimum selection of energy sources creates conflicts, especially in democratic decision-making. Resource management is both incremental and participatory, and while decisions are strongly based on science, the decision-making process is rarely rational or comprehensive. It is difficult to estimate environmental costs, especially because there is no method for comparing the many criteria between the different energy sources since there are differences in the energy efficiency results obtained in different areas. Public opinion is of great importance and it has a huge influence on the development of the development strategies and policies that are undertaken. Therefore, as part of our analysis, we conducted research using a questionnaire to obtain opinions on fundamental issues regarding the climate and energy strategies that have been adopted in the EU. This was important for achieving the main goal of this article, which is a multidimensional analysis of activities aimed at adapting the national economy to the EU strategies that are responsible for reaching the energy and climate goals by 2050. The low-emission energy transformation is aimed at introducing significant changes for the entire economy while at the same time ensuring the implementation of the so-called European triad of goals (energy security, energy competitiveness and climate protection), which often contradict each other in practice.

Energy security has become the focus of common attention of all countries in the world. It is an effective way to promote the transformation of energy consumption structure from fossil energy consumption to renewable energy consumption at present. Based on the current development status of China, this paper mainly studies the spatial evolution process of the traditional energy and the renewable energy industry in Hebei province from the perspective of space and time, and analyzes the influencing factors in this process. The results are as follows: (1) Moran’s I of the traditional energy industry increased from 0.254515 in 2005 to 0.289301 in 2021. Moran’s I of the renewable energy industry increased from 0.31409 in 2005 to 0.426467 in 2021. This indicates the energy transition in Hebei is progressing. It is worth noting that the wind and solar energy industries are both higher than the national average; (2) the spatial diffusion effect of the energy industry in Hebei province becomes more and more significant with the transformation of regional energy industry, forming a spatial distribution trend of southwest to northeast axial diffusion; (3) from 2005 to 2018, the number of green productivity factors affecting the development of both traditional and renewable energy industries increased from 2 to 6. The transformation process of the energy industry in Hebei province is influenced by different factors in different temporal stages.

The present paper indicates that hydropower, including small hydropower plants (SHPs), may play a very important role in Poland’s energy transformation in the near future. The development of SHPs may also increase water resources in the steppe Poland. Additionally, the aim of the present research is to conduct the PEST analysis of SHPs in Poland, taking into account the SHP potential. For the first time, maps showing the power and location of potential SHPs on the existing dams in Poland are presented. SHPs should be an important element of energy transition in Poland, especially on a local scale—it is stable energy production. Our analysis shows that there are 16,185 such dams in Poland, while the total capacity of potential hydropower plants in Poland would be 523.6 MW, and the total number of new jobs is estimated at 524. It was calculated that the annual avoided carbon dioxide emissions will amount to 4.4 million tons, which will reduce Poland’s emissions by 1.4%. The construction of SHPs can bring significant environmental and economic benefits. As far as the PEST analysis is concerned, the political environment of SHPs in Poland can be described as unfavorable (2.86 points). The economical nature of PEST analysis (3.86 points) should be considered as friendly for the development of SHPs. The social nature of PEST analysis can be considered as neutral (3.36 points). The technological nature of the PEST analysis can be considered as neutral (3.21 points).

Due to the energy transformation in buildings, the proportions of energy consumption for heating, ventilation and domestic hot water preparation (DHW) have changed. The latter component can now play a significant role, not only in the context of the annual heat demand, but also in the context of selecting the peak power of the heat source. In this paper, the comparison of chosen methods for its calculation is presented. The results show that for contemporary residential buildings, the peak power for DHW preparation can achieve the same or higher value as the peak power for heating and ventilation. For this reason, nowadays the correct selection of the peak power of a heat source for DHW purposes becomes more important, especially if it uses renewable energy sources, because it affects its size and so the investment cost and economic efficiency. It is also indicated that in modern buildings, mainly accumulative systems with hot water storage tanks should be taken into account because they are less sensitive to design errors (wrongly selected peak value in the context of the uncertainty of hot water consumption) and because they result in acceptable value of peak power for DHW in comparison to heating and ventilation.

Resource usage and environmental consequences of most current energy systems exceed planetary boundaries. The transition to sustainable energy systems is accompanied by a multitude of research methods, as energy systems are complex structures of technical, economical, social and ecological interactions. The description of different discipline’s perspectives in this paper show that a more mutual understanding between disciplines of their respective focus is necessary as they partly create internally competitive views arising from differing emphasis of connected matters. The purpose of this paper is to present a framework for interdisciplinary proceeding in a complex energy system transition process. Resilience thinking is chosen as a core concept for a more holistic view on sustainable energy system development. It is shown that it is already widely used in different disciplines connected to energy system research and is especially suitable due to its wide application across disciplines. The seven principles of resilience thinking (maintain redundancy and diversity, manage connectivity, manage slow variables and feedback, foster complex adaptive systems thinking, encourage learning, broaden participation, and promote polycentric governance systems) are chosen as the basis for a procedure that can be utilized to increase the interdisciplinary perspectives of energy system transitions. For energy transition processes based on scenario development, backcasting and pathway definition, resilience thinking principles are used to assess the resilience of the target energy system, the pathway resilience and the design of the scenario process with respect to the probability of a resilient outcome. The described procedure consisting of questions and parameters can be applied as a first attempt for a resilience assessment of energy transition processes. The perspective of resilience in sustainable energy systems strengthens the importance of diversity, redundancy and flexibility, which reduces the current dominant focus on efficiency of the overall system.

Greenhouse gas emissions are the main cause of today's climate change. To address this problem, the world is in an era of new round energy transformation, and the existing energy structure is being reformed. In this paper, according to the Chinese government's action plan for coping with climate change, the China's wind energy sustainable development goals and development route are discussed, and the countermeasures and suggestions are put forward. Wind energy is currently a kind of important renewable energy with matured technology which can be scale-up developed and put into commercial application, and in this transformation, wind energy will play a key role with other non-fossil energy sources. The development and utilization of wind energy is a systematic project, which needs to be solved from the aspects of policy, technology and management. At present, China is in the stage of transferring from “large wind power country” to “strong wind power country”, opportunities and challenges coexist, and the advantages of China's socialist system could be fully used, which can concentrate power to do big things and make contribution in the process of realizing global energy transformation.

The energy transformation is changing the structure of the energy sector in Europe and Germany. In this paper the current structure of the energy sector is analysed both empirically as well as theoretically. Therefore, the authors have developed the business model framework for the energy transformation (BMFE). The framework is a synthesis of classical business model designs. An exhaustive survey of existing business models based on primary data collection and a literature review leads to 638 business models. Finally, 69 prototypical business models of the energy sector are the result of the classification of these business models. The information of the business models within the BMFE is applied to show the growing importance of value creation networks in energy industry. The work represents the current status of the business models in the energy sector.

This paper presents the results of research related to the transformation of electrical energy into potential and kinetic energy of waves generated on the water surface. The waves are generated to model the environmental conditions for the needs of the model tests. The model tests are performed on model-scale objects to predict the features of full-scale maritime objects. It is done to improve human safety and the survivability of constructions. Electrical energy is transformed into the energy of the water waves using a wave maker. The wave maker considered is a facility with an electrohydraulic drive and an actuator submerged into the water. The actuator movement results in the waves being mechanically-generated in accordance with the wave maker theory. The study aimed to investigate the advantage of the newly implemented fuzzy-logic controller over the hitherto cascading proportional-integral controllers of the wave maker actuator. The research was focused on experimental investigation of the transformation process outcomes harvested under the fuzzy-logic controller, versus the cascading proportional-integral controllers. The waves were generated and measured in the real towing tank, located in the Maritime Advanced Research Centre (CTO S.A.). The investigation confirmed the advantage of the fuzzy-logic controller. It provides more accurate transformation of energy into the desired form of the water waves of specified parameters—frequency and amplitude—and more flat amplitude-frequency characteristic of the transformation process.

Electric traction in Poland is supplied with dc voltage which is obtained from the power grid via traction substations equipped with transformers and rectifiers. The paper gives the results of the investigation of different designs of these transformer-rectfier sets – namely, 12- and 24-pulse systems. The comparison of electrical quantities such as ripple content, harmonic content of supply current and output voltage and utilisation of transformer secondary windings is provided.

Electric traction in Poland is supplied with dc voltage which is obtained from the power grid via traction substations equipped with transformers and rectifiers. The paper gives the results of the investigation of different designs of these transformerâ€rectfier sets †namely, 12†and 24â€pulse systems. The comparison of electrical quantities such as ripple content, harmonic content of supply current and output voltage and utilisation of transformer secondary windings is provided. First Published Online: 27 Oct 2010