• Energy Research

This study aimed at determining the survivability of probiotic bacteria cultures in model non-dairy beverages subjected or not to the fermentation and storage processes, representing milk substitutes. The experimental material included milks produced from desiccated coconut and non-dehulled seeds of hemp (Cannabis sativa L.). The plant milks were subjected to chemical and microbiological evaluation immediately after preparation as well as on day 7, 14, and 21 of their cold storage. Study results proved that the produced and modified plant non-dairy beverages could be the matrix for probiotic bacteria. The fermentation process contributed to increased survivability of Lactobacillus casei subsp. rhamnosus in both coconut and hemp milk. During 21-day storage of inoculated milk substitutes, the best survivability of Lactobacillus casei was determined in the fermented coconut milk. On day 21 of cold storage, the number of viable Lactobacillus casei cells in the fermented coconut and hemp milks ensured meeting the therapeutic criterion. Due to their nutritional composition and cell count of bacteria having a beneficial effect on the human body, the analyzed groceries—offering an alternative to milk—represent a category of novel food products and their manufacture will contribute to the sustainable development of food production and to food security assurance.

Optimization of plant fertilization is an important element of all quality systems in primary production, such as Integrated Production, GLOBAL G.A.P. (Good Agriculture Practice) or SAI (Sustainable Agriculture Initiative). Fertilization is the most important element of agricultural treatments, affecting the quantity and quality of crops. The aim of the study was to assess greenhouse gas (GHG) emissions in the cultivation of Chinese cabbage, depending on the technological variant. The factor modifying the production technology was the use of fertilizers with a slow release of nutrients. One tonne of marketable Chinese cabbage crop was selected as the functional unit. To achieve the research goal, a strict field experiment was carried out. Calculation of the total amount of GHG emitted from the crop was made in accordance with ISO 14040 and ISO 14044. The system boundaries included the production and use of fertilizers and pesticides, energy consumption for agricultural practices and the emission of gases from soil resources and harvesting residue. The use of slow-release fertilizers resulted in a greater marketable yield of cabbage compared to conventional fertilizers. The results of the research indicate a significant potential for the use of slow-release fertilizers in reducing agricultural emissions. From the environmental and production point of view, the most favourable variant is the one with 108 kg N·ha−1 slow-release fertilizers. At a higher dose of this element, no increase in crop yield was observed. At this nitrogen dose, a 30% reduction in total GHG emissions and a 50% reduction in fertilizer emissions from the use of per product functional unit were observed. The reference object was fertilization in accordance with production practice in the test area.

Globalization of the food market is associated with the possibility of selling products into newer markets. However, it is also associated with the necessity to ensure proper quality products. Quality defined by the ISO 9001:2015 standard consists of factors that are part of customers’ expectations concerning the safety of products and the technology of their manufacture. Currently, consumers are looking for products with defined and reproducible sensory properties, in which the content of harmful substances is below the critical values specified by legislation. This is observable particularly in developed countries. The second quality factor is the use of a production technology where negative environmental impacts are reduced. Recently, issues associated with protecting workers’ rights and social needs have also become very important. In successive versions of quality management systems, such as GLOBAL G.A.P. or SAI Platform, social issues are becoming more and more important. The aim of this study was to assess the role of risk analysis for social practices in small farms in building a quality management system. Surveys were conducted in 2018. The surveys covered 62 vegetables or fruit farms with a cultivated area of up to 20 ha. Their lack of staff was due to the character of production. Where mechanic production is possible in small farms, family members can secure workforce demand. To achieve the research objective, a risk analysis was carried out for the implementation of social practices according to the guidelines of the ISO 31000:2018 standard. The criteria and inventory of identified risks were carried out, based on the guidelines of GLOBAL G.A.P. Risk Assessments on Social Practice (GRASP). Based on the identified risks, the areas relating to social practices, which require improvement in order to satisfy compliance with the GLOBAL G.A.P. standard, were indicated. The results of the conducted research pointed to a high risk of good social practices not being carried out and not meeting compliance with the requirements of the GLOBAL G.A.P. standard. The most important identified problems are associated with the deficiency of competent workers as well as the lack of facilities where workers can rest, eat and drink. A considerable problem is the conformity of employment contracts with local legislation and ensuring that work time and rest time are consistent with the law. In conditions of small farms in Poland, the problem with ensuring compliance with the standard in question is often the small number of workers. Creating an organized quality management system in the area of social practices is difficult in these cases, and sometimes even impossible.

In Poland, the development of photovoltaic (PV) installations is an important element in the development of the Renewable Energy Sources (RES) sector and supports the prosumer power industry. The purpose of the article is to present a case study of the PROSUMENT program. It analyzes the data available to date on the development of the PV market in Poland. Apart from the costs of installing the PV systems, the article analyzes the profitability of investment for different micro-power installation capacities. A calculation for micro-power installations subsidized under the PROSUMENT program for various PV capacities is presented, along with the actual amount of the subsidy. The adopted calculation methodology is a comparative verification analysis of the investment cost estimate for a for the two studied PV facilities, i.e., Micro-power installation 1 and Micro-power installation 2. The building’s annual energy demand was adopted at the same level for both examples, with fixed active energy and distribution fees. The study includes a cost estimate for installing the PV systems and the profitability of the investments for various micro-power installation capacities. The analysis of the subsidy under the PROSUMENT program demonstrated that, in the analyzed period of 2016–2020, the best results were achieved by investments with a capacity of 10 kWp. In terms of the net subsidy value, the best results ranged between 27.20 and 19.10% of the total investment costs. Development of the Polish prosumer power market requires building public awareness of prosumer power production as an opportunity for the growth of the Polish economy.

Abstract The objective of the paper was to present straw pellets production technology and to determine their production costs. The paper presents also the cost structure and economic effectiveness of pellets production. Tests were carried out in EKO-BIOMASA company which produces pellets. It is located in Biechów in Świętokrzyskie Voivodeship. Unit costs of pellets production were: 310.20 PLN ∙ t-1 for option 1, 285.40 PLN ∙ t-1 for option 2 and 278.90 PLN ∙ t-1 for option 3. The most favourable was option 3 when the pellet production was carried out on the technology line in the 3-shift system day and night. In all three variants of pellet production, the highest costs were in case of electric energy. Its participation in the cost structure in relation to the option was within 42% (option 3) and 38% (option 1). The obtained indicator of economic effectiveness for all the investigated options was higher than one.

The modern education process requires introduction of modern information and communication technologies (ICT) in order to make classes more attractive, to properly implement curricular content and, as a consequence, to provide students with education compliant with applicable standards. Some didactic classes are more predisposed to the use of ICT, and others to a lesser extent. The Faculty of Production and Power Engineering of the University of Agriculture in Krakow has been using modern IT solutions to support the teaching process for many years. The mentioned ICT tools include the e-learning platform Moodle, office packages (Microsoft Office, Open Office), groupware tools, Internet platform Google Apps, Microsoft IT Academy and many specialized software. This study presents a case study of the use of ICT tools during selected subjects at the faculty.

Adequate management of biomass residues generated by agricultural and food industry can reduce their negative impacts on the environment. The alternative use for agricultural waste is production of biogas. Biomass feedstock intended as a substrate for the agricultural biogas plants may include energy crops, bio-waste, products of animal and plant origin and organic residues from food production. This study reviews the potential of selected biomass residues from the agri-food industry in terms of use for agricultural biogas production in Poland. The most common agri-food residues used as substrates for biogas plants in Poland are maize silage, slurry, and distillery waste. It is important that the input for the agricultural biogas installations can be based on local wastes and co-products that require appropriate disposal or storage conditions and might be burdensome for the environment. The study also discusses several limitations that might have an unfavourable impact regarding biogas plants development in Poland. Given the estimated biomass potential, the assumptions defining the scope of use of agricultural biogas and the undeniable benefits provided by biogas production, agricultural biogas plants should be considered as a promising branch of sustainable electricity and thermal energy production in Poland, especially in rural areas.

Agricultural biogas plant operations are energy sources that fit well with rural land use. The continuous increase in cattle and pigs creates the need to manage animal waste, especially slurry. Using it for energy production in biogas plants offers the possibility of obtaining electricity, heat, and highly efficient manure. The thermal energy generated in an agricultural biogas plant is used to heat the substrate in the fermentation process and can also be used to heat buildings, dry fodder, or wood. Electricity can be used to cover the farm’s needs and sold to an energy company. However, the energy generated in the biogas plant must be of the right quality. One of the main factors describing the quality of electricity is the voltage distortion from the sinusoidal waveform. This paper presents the results of a study of the impact of biogas plant operation on the course of voltage and current in the grid. The theoretical analysis of the voltage distortion mechanism at the point of connection of an agricultural biogas plant was based on a simplified power system model consisting of a voltage source and the equivalent impedance of the power system. According to the theoretical analyses, agricultural biogas plant operation should reduce the voltage distortion factor. In order to confirm this statement, field tests were carried out at three agricultural biogas plants, based on which an analysis was made of the impact of the power generated in the biogas plants on the value of voltage distortion occurring at the point of their connection. However, the field tests did not confirm the conclusion of the theoretical analysis. Only in one case (where the biogas plant was connected near a substation and there was the highest short-circuit power) could it be seen that an increase in generation affected the voltage distortion factor. In the other two cases, generation did not significantly affect the shape of the voltage waveform. However, in each of the biogas plants studied, as the generation power increased, the current distortion factor decreased, suggesting that agricultural biogas plants should operate as close to the rated power as possible.