• Energy Research

Landfill gas recovery and utilisation is a solution which reduces the adverse environmental impact of the landfill. Combined heat and power (CHP) generation improves the energy balance of the facility and enables the optimal management of energy generated from a renewable source. This article aims to analyse the operation of the CHP unit in two aspects, that is, in terms of energy generation efficiency and operational availability. Energy ratios were calculated and the analysis was based on the Weibull distribution in order to assess the CHP unit’s operational reliability to minimise costs and maximise energy production. The results of the investigations and analyses demonstrated an increase of the gas yield by 29.5%, an increase of energy production by approx. 42%, and the reduction of downtime by 28.2% from 2018 to 2022. Studies related to the efficiency and reliability of operation of the cogeneration unit showed an increase in all the main parameters analysed, which resulted in greater energy and operational efficiency. The research which has been conducted is a significant scientific contribution to the optimisation of the “waste-to-energy” process for cogeneration units with the capacity of up to 0.5 MW.

The energy transition currently defines the economic development of all market sectors, driven by technological progress and increasing environmental awareness. The requirements of a sustainable economy and green energy are evolving dynamically to address environmental challenges, emphasizing the reduction of CO2 emissions as well as energy efficiency and renewable energy sources. It is essential to study consumer attitudes toward products manufactured using green energy, including FMCG (fast-moving consumer goods) products. The aim of this article is to examine the impact of the energy transformation, and consequently rising energy costs, on the decision-making process of consumers of FMCG products produced in accordance with the principles of sustainable development (including green energy). It explores the factors influencing their purchasing decisions and the role that generation plays in this process. Understanding how different generations respond to the energy aspects of economic functioning is crucial for the future development of the energy sector and the implementation of sustainable economic models. Therefore, it is essential to conduct research that demonstrates the extent of the influence of increasing consumer awareness of energy transformation within the framework of sustainable development.

The sewage treatment plant, as a producer of renewable energy, should make every effort to ensure that the biogas used as a fuel meets the quality requirements, including those of the manufacturers of cogeneration units. Such measures necessitate the application of a conditioning process of biogas in order to remove harmful compounds, so that its parameters ensure failure-free operation of engines. The aim of the research was to evaluate the effectiveness of biogas treatment in the A-type installation using the "wet biogas treatment" technology, and in the B-type installation, which is a comprehensive solution comprising sulfur removal as a result of a simultaneous regeneration of the bed with oxygen, removal of siloxanes on activated carbon, cooling and heating of biogas along with its filtration. The analysis of the results of biogas testing for these two installations demonstrated fundamental qualitative differences for the benefit of the installation B, in which the biogas was characterized by a much lower content, mainly of sulfur, hydrogen sulfide, siloxanes and humidity. The introduced pollution indicator of a megawatt hour produced in cogeneration one has confirmed much higher pollution load from the A-type installation. The hybrid solution applied in the work with simultaneous regeneration of the bed has confirmed the efficiency of biogas conditioning. Such a solution contributes to a safe and reliable operation of the cogeneration system for generating energy from a renewable source, which in turn contributes to the optimization of energy.

Removing impurities that occur in landfill gas, from sulphur and silicon compounds, is crucial for the energetic use of biogas in a cogeneration unit for energy purposes. The aim of this study was to analyse the shaped activated carbon, examining its structure and elemental composition as part of the biogas purification. The qualitative study of the purified landfill gas performed in this study showed a significant overshoot of hydrogen sulphide at 304.1 ppm with respect to the gas engine manufacturer’s requirements, while the calculated hydrogen sulphide reduction efficiency was 24.58%. Examination of the surface of the spent carbon and its pores with a scanning microscope revealed a high level of clotting by sulphur compounds, which prevents proper reduction of this compound and reduces the efficiency of the treatment plant. Replacement of the activated carbon bed with a new one showed a hydrogen sulphide value of 7.5 ppm in the purified gas and a calculated reduction efficiency of 97.9%. The results of the study confirmed that continuous monitoring of the quality of the purified gas is necessary to control the adsorption properties of the activated carbon and can be used for the operation of gas engines in cogeneration units. The landfill gas treatment method described in this paper constitutes an environmentally sustainable project within the meaning of the EU regulation on the establishment of a framework to promote and facilitate this type of investment in terms of its financing and operation. The topic of the work fits into three key areas of broad research and implementation activities. The first, technological, is the transition to a low-carbon, sustainable and resource-efficient closed-loop economy; the second, environmental, pollution prevention and control. The third area is economics and finance in terms of making financial products available designed to reduce climate change and reporting on these activities.

Combined heat and power generation is the simultaneous conversion of primary energy (in the form of fuel) in a technical system into useful thermal and mechanical energy (as the basis for the generation of electricity). This method of energy conversion offers a high degree of efficiency (i.e., very efficient conversion of fuel to useful energy). In the context of energy system transformation, combined heat and power (CHP) is a fundamental pillar and link between the volatile electricity market and the heat market, which enables better planning. This article presents an advanced model for the production of fuel mixtures based on landfill biogas in the context of energy use in CHP units. The search for optimal technological solutions in energy management requires specialized domain-specific knowledge which, using advanced algorithmic models, has the potential to become an essential element in real-time intelligent ICT systems. Numerical modeling makes it possible to build systems based on the knowledge of complex systems, processes, and equipment in a relatively short time. The focus was on analyzing the applicability of algorithmic models based on artificial intelligence implemented in the supervisory control systems (SCADA-type systems including Virtual SCADA) of technological processes in waste management systems. The novelty of the presented solution is the application of predictive diagnostic tools based on multithreaded polymorphic models, supporting making decisions that control complex technological processes and objects and solving the problem of optimal control for intelligent dynamic objects with a logical representation of knowledge about the process, the control object, and the control, for which the learning process consists of successive validation and updating of knowledge and using the results of this updating to determine control decisions.

This work focused on the verification of the electrical parameters and the durability of side connectors installed in glass–glass photovoltaic modules. Ensuring the safe use of photovoltaic modules is achieved, among others, by using electrical connectors connecting the PV cell circuit inside the laminate with an external electric cable. In most of the cases for standard PV modules, the electrical connector in the form of a junction box is attached from the back side of the PV module. The junction box is glued to the module surface with silicone where the busbars were previously brought out of the laminate through specially prepared holes. An alternative method is to place connectors on the edge of the module, laminating part of it. In such a case, the specially prepared “wings” of the connector are tightly and permanently connected using laminating foil, between two glass panes protecting against an electrical breakdown. Additionally, this approach eliminates the process of preparing holes on the back side of the module, which is especially complicated and time-consuming in the case of glass–glass modules. Moreover, side connectors are desirable in BIPV applications because they allow for a more flexible design of installations on façades and walls of buildings. A series of samples were prepared in the form of PV G-G modules with side connectors, which were then subjected to testing the connectors for the influence of environmental conditions. All samples were characterized before and after the effect of environmental conditions according to PN-EN-61215-2 standards. Insulation resistance tests were performed in dry and wet conditions, ensuring full contact of the tested sample with water. For all modules, before being placed in the climatic chamber, the resistance values were far above the minimum value required by the standards, allowing the module to be safely used. For the dry tests, the resistance values were in the range of GΩ, while for the wet tests, the obtained values were in the range of MΩ. In further work, the modules were subjected to environmental influences in accordance with MQT-11, MQT-12, and MQT-13 and then subjected to electrical measurements again. A simulation of the impact of changing climatic conditions on the module test showed that the insulation resistance value is reduced by an order of magnitude for both the dry and wet tests. Additionally, one can observe visual changes where the lamination foil is in contact with the connector. The measurements carried out in this work show the potential of side connectors and their advantage over rear junction boxes, but also the technological challenges that need to be overcome.

An attempt was made to estimate the annual production of CH4 at a municipal waste landfill site in Poland. As a matter of fact, the extent of the unorganized emission of CH4 from the landfill surface was approached based on the adopted mathematical model. The Ward agglomeration method for cluster analysis and the Pearson coefficient were employed to evaluate the distance-based similarity measure and to optimize methods for estimating methane emissions from a landfill as well as to verify the input parameters for the model. In order to calculate the content of biodegradable organic parts in the waste, morphological tests of the landfilled waste were performed. Physical quantities, measurements and the actual amount of the landfilled waste as well as the volume of CH4 neutralized in a collective flare were implemented in the model, respectively. The model-based findings and experimental outcome demonstrated stable gas production in the landfill with a high CH4 content. On the other hand, a rather low efficiency of the landfill passive degassing installation indicated the necessity to design and develop its active counterpart with the prospective application of the generated biogas for energy production in a cogeneration system.