The aim of the paper is to draw attention to risks and challenges faced by the national grid infrastructure both in the area of transmission and distribution. The study presents the characteristics of the network grid in the area of transmission and distribution. The threats concerning the transmission and distribution infrastructure were also discussed. Both the national transmission and the distribution grids are adapted to presently occurring typical conditions of the demand on electricity and to the execution of internal tasks in normal states, but they may pose a potential threat to the security of the energy supplies. In the context of the forecasted future growth of the electricity demand, the insufficient capacity of the National Power System in domestic sources and sources available through interconnections, the uneven distribution of sources and customers with the lack of adequate grid transmission capacity, the necessity to improve the quality and reliability of energy supply to end users and to intensively develop renewable energy sources, the current grid infrastructure in the area of transmission and distribution will be insufficient. It will be necessary to expand and modernize the 400 and 220 kV transmission grid, the 110 kV distribution grid, in large urban agglomerations in particular, the MV distribution grid in rural areas in particular, and to implement investments aimed at increasing the export and import capacities of the National Power System. The paper presents challenges faced by transmission and distribution system operators. They mainly concern the field of investments and the area related to the preparation and implementation of investments in the grid. These challenges result from national legislation which is inappropriate and imposes many legal and administrative barriers substantially limiting the speed and effectiveness of the investment process.

The article analyses selected aspects of the technology and logistics used to modernise a coal-fired heating plant to switch to woodchips, which is illustrated with a specific investment. The study presents characteristics of the investment’s heat economy before the modernisation, as well as the assumptions and program of the project. Finally, selected effects of the modernisation have been described

The new efficient method of modeling and thermodynamic analysis of power engineering systems has been presented. With its help a comparison of different structures and investigation of the influence of a particular constituent process onto the whole system efficiency is possible. The shaft work or the exergy is the main thermodynamic quantity taken into account in analyses, and the appropriate dimensionless modeling parameter has been introduced.

ln laboratory electrically heated entrained flow reactor with quasi one-dimensional laminar flow the influence of fuel properties on the nitrogen oxide emission for 23 coals of various rank from brown coal, bituminous coal to anthracites has been examined. For one brown coal type twofold increase of nitrogen content resulted in NO, emissions increase of about 30%. Increasing rank from brown coal to bituminous coal increases NO emissions and next a fall in the anthracites range. With nitrogen content increase NO - emission grows a~d the ratio of fuel nitrogen conversion to nitrogen oxide decreases. Experiments results and their statistical analysis were used to determine relationships describing NO, emissions and conversion ratio of fuel nitrogen to nitrogen oxide as functions of two variables. describing coal properties, i.e. nitrogen content and fuel ratio (fixed carbon to volatile matter ratio).

Is the world’s power engineering at a crossroads? Will ongoing climate changes and rise of new technologies such as the Internet of Things (IoT), Smart City or e-mobility give us a completely different perspective on the world’s future energy? What are our actual visions and development forecasts in this matter? Who is right concerning this matter, large energy companies and some politicians, environmentalists, climate researchers and all kinds of visionaries? Is transformation based on solar energy and hydrogen a holy grail for the energy sector? The author of this article tries to find answers to these and many other questions. Today we can already accept as a proven thesis that rapid and dangerous climate changes for our civilisation can also be attributed to high carbon and low-efficient power engineering. Power engineering and climate neutrality are no longer just problems for politicians, companies, and scientists, but have become a challenge for our civilisation. If we are to save the Earth, our civilisation has to change its mentality and develop ideas that will not prioritise economic growth and high consumption but sustainable growth in harmony with nature. For this to happen, the way people think about energy and global transformation must also change. The foregoing general remarks, but also the fact that a gradual transition from traditional large-scale fossil fuel-based energy generation to distributed energy generation based on renewable resources is inevitable, constitute the main message of this article. The article also aims to discuss the role of the Institute of Fluid-Flow Machinery of the Polish Academy of Sciences (IMP PAN) in Gdańsk in the process of energy transformation in our country. The institute, as the coordinating entity of over a dozen of high-budgeted national and European projects in the field of environmentally-friendly power engineering, has contributed to some extent to the creation of conditions required for the development of prosumer power engineering (or more broadly: civic power engineering) in our country.

The paper presents a brief outline of the European Union Climate and Energy Package in early 2020, as well as the EU’s plans in this respect until 2030 (Winter Package and Green Deal) and even further until 2050 (EU’s climate neutral target). Also the current condition of power generation in Poland and challenges for Polish energy sector in the nearest future are discussed. The Energy Policy of Poland until 2040 (EPP 2040) is analysed in relation to possible risks and dangers. Some improvements are proposed in regard to the implementation of the document. In addition, the current volume and perspectives of hard coal and lignite mining in Poland until 2040 are discussed and compared with an expected demand for coal in Polish power plants and combined heat and power stations. On the basis of the prognosis of energy consumption in the period 2031-2040, there seems to appear a serious risk of energy shortage due to a possible delay in a nuclear power project and lack of lignite mining at the level defined in EPP 2040 policy. Therefore, some variants of providing the security of energy supplies are taken into account and thoroughly analysed in the paper.

This paper describes the use of new methods of detecting faults in medium-voltage overhead lines built of covered conductors. The methods mainly address such faults as falling of a conductor, contacting a conductor with a tree branch, or falling a tree branch across three phases of a medium-voltage conductor. These faults cannot be detected by current digital relay protection systems. Therefore, a new system that can detect the above mentioned faults was developed. After having tested its operation, the system has already been implemented to protect mediumvoltage overhead lines built of covered conductors.

This paper focuses on the analysis of selected risks as part of investments in the power

engineering at the initial (tender) stage of the life cycle in the context of the method of

project management by the Contractor. The study was carried out on the basis of an

analysis of over 500 tenders in the power engineering, from the last 5 years, taking into

account future forecast data. The analysis carried out in this article was aimed at achieving

specific and unique goals and results aimed at creating a useful product, which is the

Contractor’s offer in the power engineering, taking into account the most significant risks.

The result of this article is to support the project team in implementing risk management

in the project at the tender stage. For this purpose, the risks with their basic parameters

were defined, which allowed for the development of a risk matrix taking into account the

data obtained in the tender procedures of leading electric power distributors. Based on

the proposed risk quantification criteria, a list of remedial actions was prepared for all risk

types listed in this article. In addition, the aspects of possible elimination/reduction of the

impact of the most significant risks that occur at the analyzed stage of the investment life

cycle were developed.

Blockchain is a technology, which could revolutionize many industries in the future. A system like that is based on a chain of blocks that is used for storing and transferring various data, forming a decentralized ledger. Although various fundamental projects based on the blockchain system in the energy industry are in their early stage of development, as well as other solutions, applications of blockchain technology in the broadly understood power engineering sector are considered to have a very large potential. This paper presents a brief description of the blockchain technology, its general operating principle and the possibilities it brings. The next section of the article contains a characterization of two exemplary and possible blockchain technology applications, which in the perspective of time may have a significant impact on the power engineering sector. The first solution is related to carrying out energy transactions, which could be conducted in an easy way directly between energy producers and consumers. Thanks to blockchain technology, this could lead to a partial decentralization in that area. The second proposed example concerns energy resources origin tracking, which would allow fixed origin attributes and parameters affecting the environment to be assigned to the generated energy. By implementing that solution, it would be possible to construct a fuel footprint of individual generating units. The article also mentions examples of other potential applications of blockchain technology in the power engineering sector.

Hydrogen-based power engineering has great potential for upgrading present and future structures of heat and electricity generation and for decarbonizing industrial technologies. The production of hydrogen and its optimal utilization in the economy and transport for the achievement of ecological and economic goals requires a wide discussion of many technological and operational – related issues as well as intensive scientific research. The introductory section of the paper indicates the main functions of hydrogen in the decarbonization of power energy generation and industrial processes, and discusses selected assumptions and conditions for the implementation of development scenarios outlined by the Hydrogen Council, 2017 and IEA, 2019. The first scenario assumes an 18% share of hydrogen in final energy consumption in 2050 and the elimination 6 Gt of carbon dioxide emissions per year. The second document was prepared in connection with the G20 summit in Japan. It presents the current state of hydrogen technology development and outlines the scenario of their development and significance, in particular until 2030. The second part of the paper presents a description of main hybrid Power-to-Power, Power-to-Gas and Power-to-Liquid technological structures with the electrolytic production of hydrogen from renewable sources. General technological diagrams of the use of water and carbon dioxide coelectrolysis in the production of fuels using F-T synthesis and the methanol production scheme are presented. Methods of integration of renewable energy with electrolytic hydrogen production technologies are indicated, and reliability indicators used in the selection of the principal modules of hybrid systems are discussed. A more detailed description is presented of the optimal method of obtaining a direct coupling of photovoltaic (PV) panels with electrolyzers.

The national power industry is based primarily on its own energy mineral resources such as hard and brown coal. Approximately 80% of electrical energy production from these minerals gives us complete energy independence and the cost of its production from coal is the lowest in comparison to other sources. Poland has, for many decades had vast resources of these minerals, the experience of their extraction and processing, the scientific-design facilities and technical factories manufacturing machines and equipment for own needs, as well as for export. Nowadays coal is and should be an important source of electrical energy and heat for the next 25–50 years, because it is one of the most reliable and price acceptable energy sources. This policy may be disturbed over the coming decades due to the depletion of active resources of hard and brown coal. The conditions for new mines development as well as for all coal mining sector development in Poland are very complicated in terms of legislation, environment, economy and image. The authors propose a set of strategic changes in the formal conditions for acquiring mining licenses. The article gives a signal to institutions responsible for national security that without proposed changes implementation in the legal and formal process it, will probably not be possible to build next brown coal, hard coal, zinc and lead ore or other minerals new mines.