The article present results of economic efficiency evaluation of storage technology for electricity from coal power plants in large-scale chemical batteries. The benefits of using a chemical lithium-ion battery in a public power plant based on hard coal were determined on the basis of data for 2018 concerning the mining process. The analysis included the potential effects of using a 400 MWh battery to optimize the operation of 350 MW power units in a coal power plant. The research team estimated financial benefits resulting from the reduction of peak loads and the work of individual power units in the optimal load range. The calculations included benefits resulting from the reduction of fuel consumption (coal and heavy fuel oil – mazout) as well as from the reduction of expenses on CO2 emission allowances.

The evaluation of the economic efficiency was enabled by a model created to calculate the NPV and IRR ratios. The research also included a sensitivity analysis which took identified risk factors associated with changes in the calculation assumptions adopted in the analysis into account. The evaluation showed that the use of large-scale chemical batteries to optimize the operation of power units of the subject coal power plant is profitable. A conducted sensitivity analysis of the economic efficiency showed that the efficiency of the battery and the costs of its construction have the greatest impact on the economic efficiency of the technology of producing electricity in a coal power plant with the use of a chemical battery. Other variables affecting the result of economic efficiency are the factors related to battery durability and fuels: battery life cycle, prices of fuels, prices of CO2 emission allowances and decrease of the battery capacity during its lifetime.

The dynamics of economic development determines the need to develop technologies for waste recycling especially the acquisition of condensed fuels for the needs of the local diversification of energy sources. In a short time, Poland will probably lack its own produced electricity. To apply the process of diversification of energy sources, by developing methods of generating energy from waste, it becomes crucial to protect the environment. The use of cogeneration technology based on fuels derived from waste, in particular concentrated oil and gas fuels, is becoming more common and provides the basis for securing the energy supply in the preferred diversification process. Plastic waste processing in the controlled depolymerization process, which is the reverse of the polymerization process for hydrocarbon recovery – uses petroleum derivatives its production. At present, the greatest interest arises in the material recovery of plastics and rubber in the process of anaerobic thermal decomposition (thermolysis/pyrolysis), which is used on an industrial scale and consists in the degradation of polymer bonds into low molecular weight. The imperative of a modern economy is to obtain energy from fuels from waste treatment, including hazardous waste, preferably in the cogeneration process. The fuel obtained from waste may be used to obtain thermal or electric energy in order to diversify energy sources. The article presents innovative Polish technologies of obtaining fuel in processes of anaerobic thermal decomposition mainly of elastomeric and polymeric waste (including hazardous ones) for direct application in power generators of various power.

About 55% of over 14 million Polish households live in multi-family buildings. Cooperative or housing association buildings have a large share in this group. The heat is supplied from the district heating network or from local sources. With respect to facilities fed from gas boiler rooms, the signing and execution of fuel supply contracts is required. From October 1, 2017, the obligation to submit tariffs for gas trading set for all final customers (except for individual gas consumers in households) for approval to the President of the Energy Regulatory Office was lifted. Decisions regarding the choice of the supplier and the content of the concluded contract are made by the authorized bodies of the cooperative or housing association. The consequences of such decisions are borne by the owners and users of residential premises. Ensuring the continuity of a contract for the supply of gaseous fuel essentially comes down to establishing prices and rates in force for a given period. The right decision on the moment of signing the contract or the amendment, termination of the existing contract and signing a new one, or negotiation efficiency will result in financial profits for all users. The costs of heating and domestic hot water preparation are a significant component of the overall cost of the maintenance of flats in Poland. Therefore, it is even more important that the prices and rates agreed upon with the gas supplier are as favorable as possible to users. The high costs of heat are not only expenses for apartment owners. The attractiveness of flat on the rental market is also decreasing. The business activity carried out in facilities located in such buildings is also less competitive.

The authors of the article analyzed gas prices on the Polish market over the last 3 years and presented the results of simulations of the effects of specific prices and rates set in the contract for the supply of fuel at the cost of heating from the point of view of a single apartment. As these are not large amounts per year, they do not motivate to optimize the terms of the gas purchase contract in this respect. The dynamics of changes in gas prices in Poland, although slightly different from world trends, is high. This makes it difficult for those responsible to make the decisions, and for residential users, it often means spending differences in subsequent years. One of the consequences of setting prices and rates significantly higher than obtainable may also be the reluctance of local communities to take measures to increase the energy efficiency of the heat supply system. From the point of view of heating costs, such decisions may distort the economic effect of thermo-modernization.

The analysis of a solar installation operation was conducted on the example of a detached house in the Lesser Poland province in Poland. A gas boiler and three flat-plate collectors are located inside the house, which are used for heating water in the hot water tank with a volume of 220 dm3. The installation was established in 2012. The heat measured system (for solar gains) was added in 2014. In 2015–2019 solar heat gains measured per area of absorber were higher than 340 kWh/m2. During a two-week period in June 2015, the insolation on the horizontal plane and the temperature were measured in 4 different points of the hot water tank. On this basis, heat losses from the storage tank were determined, i.e. a decrease in temperature during periods with and without the consumption of hot water by the residents. During this period, a temperature higher than 80°C was observed several times in the hot water tank. In two parts of the hot water tank, rhe determined temperature decreases were used to obtain the heat loss amount. In the analyzed period (2 weeks), 9 days were observed with solar heat gains higher than 9 kWh/day. For these days, the value of heat loss from the solar hot water tank was estimated at over 6 kWh/day. This data corresponds to the actual heat demand for hot water preparation in the building at 7.3 kWh/day. The correlation between daily solar heat gains and solar hot water tank heat losses were also determined. In addition, based on the amount of heat losses, the value of the tank loss coefficient was estimated. The obtained value was compared with the manufacturer’s data and reference data.

The agrarian process includes many industrial phenomena and events. The goal of economics as a science is to precisely detect and describe the relationships between various market mechanisms. These phenomena can be presented as the desire “to describe reality in terms of systems, their components and relationships, both between components of the system and between different systems” (Jankowski 1997). The energy sector is a special field among many areas of the national economy, and the products of this sector have a major impact on the branches of the economy and the mechanisms of action occurring in them. The publication is devoted to the construction of a mathematical model used to support the energy policy of local government units. The aim of the study is to build a mathematical model of energy production, taking the development potential of renewable energy into account, as well as to propose the desired direction of energy policy development in the analyzed periods to the regional authorities and to offer a model for creating an energy policy in other local government units: poviats, communes. Until now, few authors have comprehensively dealt with this issue. To date, no detailed research has been published on issues related to renewable energy development and the use of mathematical methods in the construction of the energy production model in local government units. The undertaken research is a contribution to the development of knowledge about alternative energy sources in the energy margin.

The subject of this article concerns the growing issue of implementing the concept of social responsibility in the activities of integrated energy entities. This work includes the performance of a budgetary analysis of the national leading company, in terms of expenses associated with corporate social responsibility (CSR). The article presents the analysis of source literature, as well as identifies stakeholder activities. The introduction includes an explanation of the concept of CSR, its global approach along with the justification for the need to implement the concept of CSR in the strategy of industry entities. The following were used, among others, to perform the research: elements of financial and non-financial reporting, i.e. reports of a vertically integrated energy company – Capital Group Polska Grupa Energetyczna SA, over the years 2013–2017. The data obtained from distributed sources were used. The company’s activities in social and environmental directions were identified, and the stakeholder groups of these initiatives were determined. The main purpose of this article was to estimate the level of expenditure associated with CSR in the context of the company’s general budget. The article emphasizes the role of the PGE Foundation as a recognizable point of company activity in the scope of CSR (the participation of individual group companies in financing the foundation was presented). The analysis of CSR expenditure included: the amount of taxes paid, costs of employee benefits and assets of the social services fund, and environmental costs.

The constant increase in the popularity of renewable energy systems allows residential building users to apply solutions leading to the diversification of the energy supply. The use of RES systems in residential buildings not only contributes to a higher level of environmental care, but also significantly and measurably improves the energy efficiency of the facility. Using hybrid systems allows the supply to be reduced or eliminated from conventional energy sources. The article presents common layouts of renewable energy systems, which are successfully used in residential buildings. It also shows the impact of such systems on the amount of savings achieved in the use of energy from external or conventional sources. In residential buildings, the possibility of energy generation in the form of electricity and heat is dependent on many factors that determine the type and size of the systems used to obtain energy from renewable sources. We should assume the further and continuous development of RES, which will increase the share of electricity and heat produced in households. Technological development, decreasing prices of equipment and components used for the installation of green electricity generation systems will be a conducive factor for increasing the popularity of RES systems, not only for residential buildings but also for other types of buildings. The article also points out the economic aspect of the RES systems application. It presents the positive impact of RES installations on the environment and estimates the average time of financial reimbursement. The economic analysis concerns individual systems of renewable energy systems used in residential buildings.

The European Union aspires to pursue an ambitious climate policy. The energy sector is a key tool to ensure success in this area. At the same time, excessively ambitious targets can be a serious problem for individual member states. The aim of the article is to analyze the possibilities available to the Polish energy sector in the context of the assumed EU climate neutrality goals by 2050.

The analyzed research problem concerns, in particular, two areas of strategic importance for Poland: the coal sector and the renewable energy sources sector. The role of the former should be significantly reduced in the coming decades, while the position of the latter should be substantially strengthened. The juxtaposition of these challenges with the Polish economic, social and techno- logical realities is the main subject of analysis in this text. The method of system analysis with elements of a decision-making approach will be used. This will allow for an effective analysis and review at the research level of the most important problems and challenges faced by Poland in light of the necessary adjustments to be made in order to achieve the priorities assumed by the European Union.

The hypothesis of the article is that Poland is able to effectively meet European climate targets, although the implementation of this challenge requires decisive action on the part of the government, as well as an adequate response from investors and society. To this end, appropriate actions must be undertaken at both a strategic and operational level.

There are many financial ways to intensify the construction of new renewable energy sources installations, among others: feed in tariff, grants. An example of photovoltaic grant support in Poland is the “Mój Prąd” [My Electricity] program created in 2019. This program, with a budget of PLN 1 billion, is intended for households in which installations with a capacity range of 2–10 kWp have been installed. During its first edition 27,187 application were submitted. Over 98% of installations cost less than PLN 6,000/kWp. The total installed capacity is 151.3 MWp, which gives the average amount of co-funding per unit of power at the level of PLN 884.7/kWp. The average power of the installation on the national scale is 5.57 kWp, the indicator per 1000 inhabitants is 3.94 kWp, and per unit of area is 0.484 kWp/km2. These installations will produce around 143.5 GWh of electricity annually, contributing to the reduction of CO2 emissions by approximately 109,800 Mg per year. Most applications came from the Silesian Province (3855), which translated into the largest installed capacity of 21.82 MWp, as well as 4.81 kWp/1000 inhabitants and 1.77 kWp/km2 (over 3 times higher than the average in Poland). The installed capacity in the individual province was closely correlated with the population of the province (correlation coefficient – 0.95), while the installed capacity indicator per 1,000 inhabitants with insolation (0.80). The highest power ratio per 1000 inhabitants was achieved in the Podkarpackie Province and amounted to 5.05, and the lowest in the West Pomeranian Province (2.41).

Actinomycetes are considered to be the biggest producer of bioactive compounds which are expected to have antifungal activity for controlling many fungi such as Rhizoctonia solani. The objective of this study was to obtain potential soybean rhizosphere actinomycetes as a biocontrol agent for R. solani which cause damping-off disease both in vitro and in vivo, including their ability to produce siderophore, chitinase, and HCN. Out of 26 isolates, 18 (56%) showed diverse antifungal activities against R. solani with percentages of inhibition radial growth (PIRG) from 18.9 to 64.8%, as evaluated by a dual culture method. Ten isolates with the strongest antifungal activity were numbered for further characterization. All the tested isolates were not antagonistic towards Bradyrhizobium japonicum. These isolates were able to suppress damping-off disease caused by R. solani in the greenhouse experiment. Isolate ASR53 showed the highest disease suppression, 68% and 91% in sterile and non-sterile soil, respectively. Based on 16S rRNA sequence analysis this isolate belonged to Streptomyces violaceorubidus LMG 20319 (similarity 98.8%) according to GenBank data base available at www.ncbi.nlm.gov.nih. Furthermore, isolate ASR53 had significantly longer roots and shoots, as well as greater fresh and dry weights of seedlings than the control. Crude extract derived from ASR53 isolates contained 10 dominant compounds that were biologically active against fungal pathogens. Thus, this study suggests that the application of potential actinomycetes of the soybean rhizosphere can act as a promising biocontrol agent against damping-off disease caused by R. solani.

High temperature behavior of three compacted graphite iron (CGI) alloys on polycrystalline alumina substrates (99.7%, poro­sity <3%) were examined by the sessile drop method combined with classical contact heating procedure in flowing Ar. High-speed high-resolution CCD camera was used for continuous recording of the CGI/Al2O3 couples during melting alloy, heating to and holding the couples at the test temperature of 1450°C for 15 min and their subsequent cooling. The comparative studies were made with conventional CGI (in wt.%: 3.70 C, 2.30 Si, 0.44 Mn, 0.054 P, 0.017 Mg, 0.015 S) and two alloys additionally containing the same amounts of 0.25 Mo, 0.1 V, 0.045 Sn and 0.032 Sb with different concentrations of Mg + Cu additions, i.e. 0.01Mg + 0.33Cu and 0.02Mg + 0.83Cu. All three CGI alloys demonstrated non-wetting behavior on the Al2O3 substrates while the contact angle values slightly decreased with increase of the Mg + Cu content in the alloy, i.e. 131° (unalloyed CGI), 130° (0.01Mg + 0.33Cu) and 125° (0.02Mg + 0.83Cu). Structural characterization of solidified couples by light microscopy and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy revealed: 1) heterogeneous nucleation of discontinuous graphite layer at the drop-side interfaces and on the surface of the drops; 2) reactively formed Mg-rich oxide layer at the substrate-side interface; 3) the formation of satellite droplets on the surface of the drops during their solidification; 4) degeneration of initially compacted graphite to lamellar graphite after remelting and subsequent solidification of the drops, particularly in their surface layer.

In this paper, the kinetics of the platinum(IV) chloride complex ions reduction reaction was studied. It was shown that the mechanism exhibits autocatalytic character. The presence of metallic platinum in the system significantly increases the reaction rate. The influence of the initial concentration of precursor, reductant, ionic strength, initial concentration of the chloride ions as well as the temperature on the process rate was investigated. The activation energy was determined and is equal to 93.57 kJ/mol. Moreover, the obtained metallic phase was analyzed, and it was observed that it has a micrometric size.

Mg-1.6Gd binary alloy was subjected to uniaxial warm rolling at a unidirectional and cross-sectional with a reduction ratio of 95% in order to observe the relationship between its microstructural changes to the degradation behavior. The warm rolling was performed at a temperature range of its recrystallization temperature, which were 400°C and 560°C, and a feed rate of 10 mm/min. Degradation behaviors of Mg-1.6Gd binary alloy was evaluated by means of potentiodynamic polarization and hydrogen evolution test in modified Kokubo’s SBF solution at temperature of 37 ± 1ºC. The lowest corrosion rate of 0.126 mm/year derived from potentiodynamic polarization test was showed by unidirectional-rolled specimen at temperature of 560 °C. Hydrogen evolution test results showed the lowest hydrogen gas formed during 24 hours of immersion was found on unidirectional-rolled specimen at temperature of 560°C with a rate of 0.268 cc/cm2/hours. While cross rolled specimens showed a high corrosion and hydrogen evolution rate of 20 mm/year and 0.28 cc/cm2/hours.

Ice formed on radome surfaces causes communication disruption due to radio-frequency interference (RFI), which reveals the importance of de-icing systems for radomes. As a radome de-icing application, in this work, carbon nanotube (CNT) thin films were fabricated using a spray-coating method, and influence of process parameters on RF transmittance and electrothermal properties was investigated. With the increase of spraying time, sheet resistance of the fabricated film decreases, which results in a decrease of the RF transmittance and improvement of the heating performance. Also, the de-icing capability of the fabricated CNT film was evaluated at –20oC, and efficient removal of ice under cold conditions was demonstrated.

In this study, Fe-40wt% TiB2 nanocomposite powders were fabricated by two different methods: (1) conventional powder metallurgical process by simple high-energy ball-milling of Fe and TiB2 elemental powders (ex-situ method) and (2) high-energy ball-milling of the powder mixture of (FeB+TiH2) followed by reaction synthesis at high temperature (in-situ method). The ex-situ powder was prepared by planetary ball-milling at 700 rpm for 2 h under an Ar-gas atmosphere. The in-situ powder was prepared under the same milling condition and heat-treated at 900oC for 2 h under flowing argon gas in a tube furnace to form TiB2 particulates through a reaction between FeB and Ti. Both Fe-TiB2 composite powder compacts were sintered by a spark-plasma sintering (SPS) process. Sintering was performed at 1150℃ for the ex-situ powder compact and at 1080℃ for the in-situ powder for 10 minutes under 50 MPa of sintering pressure and 0.1 Pa vacuum for both processes. The heating rate was 50o/min to reach the sintering temperature. Results from analysis of shrinkage and microstructural observation showed that the in-situ composite powder compacts had a homogeneous and fine microstructure compared to the ex-situ preparation, even though the sintered densities were almost the same (99.6 and 99.8% relative density, respectively).

In the past few years, overhead copper transmission lines have been replaced by lightweight aluminum transmission lines to minimize the cost and prevent the sagging of heavier copper transmission lines. High strength aluminum alloys are used as the core of the overhead transmission lines because of the low strength of the conductor line. However, alloying copper with aluminum causes a reduction in electrical conductivity due to the solid solution of each component. Therefore, in this study, the authors attempt to study the effect of various Al/Cu ratios (9:1, 7:3, 5:5) to obtain a high strength Al-Cu alloy without a significant loss in its conductivity through powder metallurgy. Low-temperature extrusion of Al/Cu powder was done at 350ºC to minimize the alloying reactions. The as-extruded microstructure was analyzed and various phases (Cu9Al4, CuAl2) were determined. The tensile strength and electrical conductivity of different mixing ratios of Al and Cu powders were studied. The results suggest that the tensile strength of samples is improved considerably while the conductivity falls slightly but lies within the limits of applications.

With the recent advancement in technology for titanium metal powder injection molding and additive manufacturing, high yield and good flowability powder production is needed. In this study, titanium powder was produced through vacuum induction melting gas atomization with a cold crucible, which can yield various alloy compositions without the need for material pretreatment. The gas behavior in the injection section was simulated according to the orifice protrusion length for effective powder production, and powder was prepared based on the simulation results. The gas distribution changes with the orifice protrusion length, which changes the location of the recirculation zone and production yield of the powder. The produced powders had a spherical morphology, and the content of impurities (N, O) changed with the injected-gas purity.

In this study, we demonstrate a facile and cost-effective way to synthesize Nd-Fe-B of various shapes such as powders, rods and fibers using electrospinning, heat-treatment and washing procedures. Initially Nd-Fe-B fibers were fabricated using electrospinning. The as-spun Nd-Fe-B fibers had diameters ranging 489 to 630 nm depending on the PVP concentration in reaction solutions. The different morphologies of the Nd2Fe14B magnetic materials were related to the difference in thickness of the as-spun fibers. The relationships between the as-spun fiber thickness, the final morphology, and magnetic properties were briefly elucidated. The intrinsic coercivity of Nd2Fe14B changed with the change in morphology from powder (3908 Oe) to fiber (4622 Oe). This work demonstrates the effect of the Nd-Fe-B magnetic properties with morphology and can be extended to the experimental design of other magnetic materials.

In this study, a non-equiatomic high entropy alloy was fabricated using the spark plasma sintering method, and its microstructural features and mechanical properties were investigated. The chemical composition of FeMnCoCr was determined by using the entropy calculation related to the design of high entropy alloys. A bulk sample with the same composition was also prepared using the conventional metallurgical processes of casting and hot rolling. The microstructures of the samples fabricated by these different processes were compared by microscope observation, and a quantitative phase analysis was carried out using FE-SEM. Hardness measurement was used to evaluate mechanical properties. Particular attention was paid to microstructural changes due to heat treatment, which was analyzed by considering how austenite stability is affected by grain refinement.

We investigated the austenite stability and mechanical properties in FeMnNiC alloy fabricated by spark plasma sintering. The addition of Mn, Ni, and C, which are known austenite stabilizing elements, increases its stability to a stable phase existing above 910°C in pure iron; as a result, austenitic microstructure can be observed at room temperature, depending on the amounts of Mn, Ni, and C added. Depending on austenite stability and the volume fraction of austenite at a given temperature, strain-induced martensite transformation during plastic deformation may occur. Both stability and the volume fraction of austenite can be controlled by several factors, including chemical composition, grain size, dislocation density, and so on. The present study investigated the effect of carbon addition on austenite stability in FeMnNi alloys containing different Mn and Ni contents. Microstructural features and mechanical properties were analyzed with regard to austenite stability.

A paste containing Cu(II) formate rods was prepared, and characteristics of sinter bonding at 250°C under a pressure of 10 MPa were investigated to accomplish a high-speed die attachment for wide-bandgap power chips on Cu finish in air. Synthesis of the plate-type Cu formate particles from CuO was accomplished through a wet reaction for 180 min. Cu, formed in situ in the bondline by pyrolysis of the formate during heating for the attachment, was sufficiently active to lead high-speed sintering within a carbon dioxide-hydrogen atmosphere derived from the pyrolysis, and the oxide layer on the Cu finish was reduced by the hydrogen. As a result, sinter bonding for 10 min formed a robust bonding with a shear strength approaching 27 MPa.

CaO sorbent dissolved in chloride molten salts was investigated to identify its CO2 capture property. Various molten salt systems with different melting points (CaCl2, LiCl, LiCl-CaCl2, and LiCl-KCl) were used to control the operation temperature from 450 to 850ºC in order to determine the effect of the operation temperature on the chemical reaction between CaO and CO2. The CaO sorbent showed the best performance at 550ºC in the LiCl-CaCl2 molten salt (conversion ratio of 85.25%). This temperature is lower than typical operation temperature of the solid-state CaO sorbent (~700ºC).

Mortar feedstock is extruded to form bead and it is selectively placed line by line in the material extrusion additive manufacturing. With respects to part building process healthiness, load-supporting ability of overlaid beads is emphasized as buildability. Buildability is primarily dependent on thixotropic properties of feedstock and vertical overlapping schedule. In the present study, water-to-binder (w/b) ratio was chosen as material aspect to assess buildability. Uneven bead shape evolution and premature failure were highlighted owing to low yield stress of high w/b ratio feedstock. Feedstock with optimum w/b ratio showed good buildability even at the interval time of 19 sec.