The expected demand for hard coal intended for the households will progressively be decreasing. This is directly related to the introduced anti-smog resolutions, as well as the growing level of environmental awareness. However, it should be noted, that the use of the modern home heating boilers will result in an increase in the demand for medium coal sizes. The shortfall of this type of coal is already observed on the market. Therefore, its import is necessary. One of the solutions to increase the supply of the medium coal sizes is the production of coal briquettes. Moreover, their use will consequently lead to reduced emissions.

The paper presents a comparison of emissions from the combustion of coal briquettes and hard coal in home heating boilers. The briquettes were characterized by significantly lower emissions than hard coal (by 52% on average). The particulate matter emissions were lower by 70%. This may significantly contribute to improving air quality in Poland and in addition, limit the occurrence of smog. The possibility of further emission reduction by using low-emission fuels as briquette components was presented. The average relative emission reduction compared to hard coal for the analyzed fuels was estimated as follows: 62% for coal char, 57% for coke, 51% for charcoal/biocarbon, 49% for anthracite, 45% for torrefied biomass, and 33% for peat.

Furthermore, the issue of the mercury content in the analyzed fuels was discussed. The lowest mercury content was found in biomass fuels, in particular biomass after thermal treatment (torrefied biomass, biocarbon, and charcoal). Fuels produced from hard coal in the pyrolysis process (coal char and coke) were characterized by very low mercury content as well.

Coal combustion processes are the main source of mercury emission to the environment in Poland. Mercury is emitted by both power and heating plants using hard and brown coals as well as in households. With an annual mercury emission in Poland at the level of 10 Mg, the households emit 0.6 Mg. In the paper, studies on the mercury release in the coal and biomass combustion process in household boilers were conducted. The mercury release factors were determined for that purpose. For the analyzed samples the mercury release factors ranged from 98.3 to 99.1% for hard coal and from 99.5% to 99.9% for biomass, respectively. Due to the high values of the determined factors, the amount of mercury released into the environment mainly depends on the mercury content in the combusted fuel. In light of the obtained results, the mercury content in the examined hard coals was 6 times higher than in the biomass (dry basis). Taking the calorific value of fuels into account, the difference in mercury content between coal and biomass decreased, but its content in coal was still 4 times higher. The mercury content determined in that way ranged from 0.7 to 1.7 μg/MJ for hard coal and from 0.1 to 0.5 μg/MJ for biomass, respectively. The main opportunity to decrease the mercury emissions from households is offered by the use of fuels with a mercury content that is as low as possible, as well as by a reduction of fuel consumption. The latter could be obtained by the use of modern boilers as well as by the thermo-modernization of buildings. It is also possible to partially reduce mercury emissions by using dust removal devices.

As recent studies showed, the post-communist countries have relatively the highest level of energy poverty in Europe. The poorest of them still are not explored. So, the authors decided to study this problem for Ukraine as one of the largest and poorest post-communist countries in Europe. This Eastern European country experienced a number of challenges before the pandemic, including a war with Russia in the east of the country, high external debt, high energy intensity and low added value of the economy. The purpose of this study is to measure how deep the energy poverty problem in Ukraine is and how it changed during the COVID-19 pandemic. Applying selected quantitative and financial indicators, the authors showed the problem of energy poverty in Ukraine remained acute at the beginning of 2020, especially in terms of heating. Moreover, its level in Ukraine was three times higher than the average level for the all the EU countries. Furthermore, in 2020, during the pandemic, there were drastic increasing arrears of households on utility bills that meant a new leap of energy poverty in Ukraine. This study did not search for the causes of the identified leap in energy poverty, which apparently connected with the global and local economic and social consequences of the pandemic. However, it revealed the depth of this problem and the lower impact of the nature factor (air temperature) on energy poverty during and after the COVID-19 pandemic. Further research is required to identify the underlying drivers and develop possible solutions to this problem in Ukraine and other European countries suffering from high energy poverty.

The coronavirus disease 2019 (COVID-19) pandemic has wreaked havoc especially in 2020 and the first half of 2021 and has left severe after-effects affecting not only the health sector but also all aspects of human life. The aim of this study is to inspect the current trends of the quantities of household waste produced during the first four waves of the pandemic. The study was carried out in Guelma city, northeastern of Algeria, where the first containment was registered on February 25, 2020, it concerns an Italian national (Mohamed et al. 2021). An increase in the production of household waste of approximately 14% during the first containment was recorded in the study area, with the interruption of recycling, which caused an enormous pressure on the technical landfill center of Guelma. The results showed that the trend of waste production decreased at the following averages: 205.80; 198.92; 196.69 and 192.43 tons, for the first four waves of COVID-19 respectively. Therefore, a return to the pre-pandemic state would be close, which dampens the impact and pressure on the landfill and the environment. This research allows for perceiving the waste management status in Algeria, between the pandemic and post-pandemic period.

The paper presents an analysis of hard coal prices offered at the coal depots in Poland. Coal depots are one of the most popular forms of purchasing coal by Polish households. Prices refer to price offers for cobble coal (grain size: 60–120 mm) and their analysis is performed based on the regions rather than on all Polish provinces. From January 2010 to May 2019, there were two regions that were distinguished in terms of price spread: the S-W region and the N-E region. In the case of the S-W region, the difference between the province with the minimum price (Śląskie Province) and with the maximum price (Dolnośląskie Province since September 2017) ranged from PLN 53–83/ton, and in the N-E region the difference ranged PLN 64–130/ton. In the case of the remaining two regions, prices varied from a few to approximately PLN 80/ton for the N-W region, and from a few to about PLN 40 /ton for the S-E region. In order to determine how the origin of the coal affects its prices (domestic coal, imported coal), the analysis also included cobble coal price offers that are part of the Author’s own database created for several years. In the case of cobble coal from domestic producers, price offers varied betwwen PLN 14–33/GJ, and price offers for imported cobble coal stood varied between PLN 12–32/GJ. The N-E region attracted particular attention as the price offers for imported cobble coal reached a level similar to the offers from the S-W region, i.e. the region closest to Silesian coal mines. Price differentials within provinces belonging to a given region were influenced by the geographical rent. The paper also analyses average selling prices offered by domestic producers for various size grades of steam coal as well as selling prices for imported coal (free-at-frontier price).

The smart household connected to the energy dispatch arises to overcome the environmental crisis, encourages the penetration of renewable energies and promotes consumer respond to intraday market prices. Aquaponic production results from the combination of fish farming and hydroponics (cultivating plants using fish waste as nutrients). The prototype was built based on the rule of the 3 Rs: reduce, reuse and recycle. The crop reduces the consumption of water and energy, reuses water in a recirculation process, which is filtered by: 1) gravity, 2) biofilters and 3) porosity. Recycling is expanded to plastic containers and food containers of polystyrene. The aquaponic production system is decorative, completely organic (without chemicals), promotes the growth of green areas for comfortable homes and allows the consumption of healthy food, as well as energy planning to save energy. The system is done with a digital level control connected to a water pump and an oxygen pump. A novel method allows the aggregator to optimize the recirculation programming of the aquaponic system for periods of 24 hours. The method maximizes the economic benefits with the help of an energy balance between hours.

The aim of this study was to determine the impact of the temperature of wastewater in a biological reactor with activated sludge and the BOD₅/N-NH₄ ratio in the influent to the treatment plant on nitrification efficiency and the concentration of ammonium nitrogen in treated wastewater. Tests were carried out in a household wastewater treatment plant which collects and treats sewage from a school building and a teacher’s house. During the 3-year study, large fluctuations in the sewage temperature in bioreactor were noted which was closely related to the ambient temperature. There were also large fluctuations in the concentration of organic matter and the concentration of ammonium nitrogen in inflowing sewage. The influence of wastewater temperature in the bioreactor and the BOD₅/N-NH₄ ratio on the concentration of ammonium nitrogen in treated wastewater was determined using Pearson’s linear correlation. A statistical analysis showed that a 1°C decrease in the temperature of wastewater in the bioreactor increased the concentration of ammonium nitrogen in treated wastewater by 2.64 mgN-NH₄·L^-1. Moreover, it was found that nitrification depended on the ratio of BOD₅ to the concentration of ammonium nitrogen in wastewater flowing into the bioreactor. An increase in the BOD₅/N-NH₄ ratio by 1 value led to a 5.41 mgN-NH₄·L^-1 decrease in the concentration of ammonium nitrogen.

This paper presents the use of multi-criteria analysis as a tool that helps choosing an adequate technology for a household wastewater treatment plant. In the process of selection the criteria of sustainable development were taken into account. Five municipal mechanical-biological treatment plants were chosen for the comparative multi-criteria analysis. Different treatment technologies, such as sand filter, activated sludge, trickling filter, a hybrid system - activated sludge/trickling filter and a hybrid constructed wetland system VF-HF type (vertical and horizontal fl ow) were taken into account. The plants’ capacities were 1 m3∙d-1 (PE=8) and they all meet the environmental regulations. Additionally, a solution with a drainage system was included into the analysis. On the basis of multi-criteria analysis it was found that the preferred wastewater treatment technologies, consistent with the principles of sustainable development, were a sand filter and a hybrid constructed wetland type VF-HF. A drainage system was chosen as the best solution due to the economic criteria, however, taking into consideration the primary (ecological) criterion, employment of such systems on a larger scale disagree with the principles of sustainable development. It was found that activated sludge is the least favourable technology. The analysis showed that this technology is not compatible with the principles of sustainable development, due to a lack of proper technological stability and low reliability.

We consider a monetary DSGE model featuring a borrowing constraint such that the amount of debt cannot be larger than a fraction - the debt-to-income (DTI) limit - of borrowers' labor income and the DTI limit is endogenous. The coexistence of financial amplification mechanisms warranted by this model provides a role for a specific macroprudential tool: a countercyclical DTI limit. Conditional on the pre-crisis sample and in a more recent out-of-sample period, our ex-post normative analysis shows that when this policy is implemented the cooperation between central bank and macroprudential authority in pursuing the “two instruments for two goals” strategy delivers an efficient performance in terms of macroeconomic stabilization, significantly outperforming the central bank's policy of “leaning against the wind”. This implies that a central bank should only be focused on its standard objectives (inflation and output stabilization) while financial stability be monitored by a macroprudential authority.

This article studies the implications of the Fourth Energy Package and relevant EU Directives for households and explores their potential benefits in Ukraine. Understanding the effects of energy policies on the residential sector is crucial for promoting sustainability amidst global energy and climate challenges. Methods of descriptive legal studies and investment analysis are used to examine the primary EU legislation on renewable energy communities and citizens’ groups, focusing on their applicability to homes and renewable energy cooperatives. The analysis of Ukraine’s experiences with the adoption of green power and incentives have revealed challenges for small solar home installations operating without the feed-in tariff. Introducing net-billing makes projects unfeasible without such a tariff, and even selling electricity through aggregators on the intraday market does not help. Consequently, the payback period for small installations with batteries becomes unreasonably long (exceeding twenty-five years), while larger facilities have shorter payback termsolytechnic Institute, Ukraine (fifteen to seventeen years). These findings highlight the need for careful consideration of household green-power policies. Implementing the Fourth Energy Package in Ukraine requires measures to address the financial feasibility of small solar installations, particularly those lacking feed-in tariff support. Expanding legislative provisions to include consumers of green power, especially those in multi-apartment buildings, can enhance their participation in the electricity producers’ market. Moreover, raising household electricity prices may be necessary to support sustainable energy practices. Overall, this study underscores the importance of evidence-based policymaking for successful power transitions in homes and the broader energy sector.

According to the European Environment Agency (EEA 2018), air quality in Poland is one of the worst in Europe. There are several sources of air pollution, but the condition of the air in Poland is primarily the result of the so-called low-stack emissions from the household sector. The main reason for the emission of pollutants is the combustion of low-quality fuels (mainly low-quality coal) and waste, and the use of obsolete heating boilers with low efficiency and without appropriate filters. The aim of the study was to evaluate the impact of measures aimed at reducing low-stack emissions from the household sector (boiler replacement, change of fuel type, and thermal insulation of buildings), resulting from environmental regulations, on the improvement of energy efficiency and the emission of pollutants from the household sector in Poland. Stochastic energy and mass balance models for a hypothetical household, which were used to assess the impact of remedial actions on the energy efficiency and emission of pollutants, have been developed. The annual energy consumption and emissions of pollutants were estimated for hypothetical households before and after the implementation of a given remedial action. The calculations, using the Monte Carlo simulation, were carried out for several thousand hypothetical households, for which the values of the technical parameters (type of residential building, residential building area, unitary energy demand for heating, type of heat source) were randomly drawn from probability distributions developed on the basis of the analysis of the domestic structure of households. The model takes the coefficients of correlation between the explanatory variables in the model into account. The obtained results were multiplied so that the number of hypothetical households was equal to 14.1 million, i.e. the real number of households in Poland. The obtained results allowed for identifying the potential for reducing the emission of pollutants such as carbon dioxide, carbon monoxide, dust, and nitrogen oxides, and improving the energy efficiency as a result of the proposed and implemented measures, aimed at reducing low-stack emission, resulting from the policy.

The potential for emissions of gaseous pollutants is 94% for CO, 49% for NOx, 90% for dust, and 87% for SO2. The potential for improving the energy efficiency in households is around 42%.

Rising carbon dioxide emissions are driving climate change and there is growing pressure to find alternative energy sources. Co-combustion of waste with fuels is still occurring in some regions of the world, and it is important to know the compounds emitted from such combustion. This study investigated the emissions from the combustion of wood pellets with waste. The wood pellet was combusted with different additions of polyethylene terephthalate plastic and medium-density fiberboard (10 and 50%), in a low-power boiler (18W). Phenols, alkylphenols, phthalates, biomass burning markers, and polycyclic aromatic hydrocarbon emissions were determined. Gas chromatography coupled with a mass spectrometry detector was used to analyze these compounds after extraction and derivatization in the particulate matter and gas phase. The emissions of biomass burning markers and phthalates were the highest among all the compounds determined for MDF addition. The total emission of these compounds was 685 mg/h and 408 mg/h for 10% addition and 2401 mg/h and 337 mg/h for 50% addition, respectively. For the co-combustion of biomass with PET, PAHs and phenols had the highest emission; the emission was 197 mg/h and 114.5 mg/h for 10% addition and 268 mg/h and 200 mg/h for 50% addition, respectively. In our opinion, the obtained results are insufficient for the identification of source apportionment from household heating. After further study, tested compounds could be treated as markers for the identification of the fuel type combusted in households.

Russia’s use of one of its energy resources as a tool of political pressure in 2021 destabilized the economies of many European countries. The energy crisis was exacerbated by the outbreak of Russia’s war with Ukraine in February 2022, when many countries, including those of the EU, responded by imposing sanctions on energy resources from Russia. The situation also affected Polish households. Until then, Russia had been Poland’s main supplier of coal and natural gas. It is estimated that 3.8 million households were threatened by the uncertainty of hard-coal supplies for the 2022/2023 heating season. The article presents an analysis of the supply and demand of the main fossil energy resources consumed by Polish households for heating purposes. Discussing the supply of a given raw material, both domestic production and imports are presented. The inability to increase domestic coal production for households in the short term (it is a long-term process) resulted in the introduction of intervention imports. In the case of imports, attention was paid to the need to change suppliers as well as import routes. The article also analyzes the prices of major energy carriers for domestic households from January 2018 to March 2023. Rapidly rising prices of hard coal at fuel depots in the third and fourth quarters of 2022 were higher than natural gas prices for households by PLN 13–16/GJ and amounted to PLN 81–101/GJ. By comparison, natural gas prices were then in the range of 65–88 PLN/GJ. In the first quarter of 2023, the prices of these two energy carriers had already reached a similar level (in the order of 80 PLN/GJ).

This article concerns the mutual expanding and enriching influence of the social history and historical demographics research issues, visible in popular historiography, at least since the end of the 20th century. The author uses selected achievements of international historiography as a backdrop for a presentation of the main achievements of Polish historical demographers, who conducted modern studies into the forms and living patterns in the territory of Poland ranging from the late mediaeval times up to the 20th century, on a larger scale than ever in the past. The article highlights the presence of new sociocultural and demographic issues such as areas of solitary females, location and significance of the elderly, occurrence of the life cycle servants phenomenon in the Old-Polish society.

We estimate the size of income underreporting in Poland by following and extending the consumption method of Pissarides and Weber (1989). Our study shows that underreporting of income occurs among households with income from self-employment. We do not find any significant underreporting activity by the employees working in the private sector. The main findings indicate that roughly one-fourth of the total income of self-employed households is not reported in Poland. This share varies between 20 to 30 percent from 2005 to 2017 with a decreasing trend.

The growing demand for fresh water and its scarcity are the major problems encountered in semi-arid cities. Two different techniques have been used to assess the main determinants of domestic water in the Sedrata City, North-East Algeria: prin-cipal component analysis (PCA) and artificial neural networks (ANNs). To create the ANNs models based on the PCA, twelve explanatory variables are initially investigated, of which nine are socio-economic parameters and three physical char-acteristics of building units. Two optimum ANNs models have been selected where correlation coefficients equal to 0.99 in training, testing and validation phases. In addition, results demonstrate that the combination of socio-economic parameters with physical characteristics of building units enhances the assessment of household water consumption.