Fuel cells are a promising source of clean energy. To find optimal parameters for their operation, modeling is necessary, which is quite difficult to implement taking into account all the significant effects occurring in them. We aim to develop a previously unrealized model in COMSOL Multiphysics that, on one hand, will consider the influence of electrochemical heating and non-isothermal fluid flow on the temperature field and reaction rates, and on the other hand, will demonstrate the operating mode of the Solid Oxide Fuel Cell (SOFC) on carbonaceous fuel. This model incorporates a range of physical phenomena, including electron and ion transport, gas species diffusion, electrochemical reactions, and heat transfer, to simulate the performance of the SOFC. The findings provide a detailed view of reactant concentration, temperature, and current distribution, enabling the calculation of power output. The developed model was compared with a 1-kW industrial prototype operating on hydrogen and showed good agreement in the volt-ampere characteristic with a deviation not exceeding 5% for the majority of the operating range. The fuel cell exhibits enhanced performance on hydrogen, generating 1340 W/m² with a current density of 0.25 A/cm². When fueled by methane, it produces 1200 W/m² at the same current density. Using synthesis gas, it reaches its peak power of 1340 W/m² at a current density of 0.3 A/cm².

The article presents an overview of experimental layout design solutions and the general operation scheme of combined heat and power systems with a high-temperature solid oxide fuel cell (SOFC). This system is an environmentally friendly and energy-saving way to produce electricity and heat. The use of high-temperature SOFCs makes it possible to obtain an electrical efficiency of 45–55%. Combining the electrochemical and mechanical system can increase the total efficiency by up to 60–65% in a hybrid power plant. This article discusses the structure and relationship between the components of a hybrid power plant and various modification options for efficient power generation. The technological schemes for existing and tested hybrid power plants with an SOFC and gas turbine are presented and described in detail. When designing a hybrid power plant, the key factors are the choice of design, heat source, and fuel-reforming method; the design of a solid oxide fuel cell and the number of modules in a stack; selecting devices for generating electricity with the development of cogeneration or trigeneration cycles (for possible use in thermal power plants and for the energy supply of social facilities); the direction of material flows within the system; pressure and tightness; and the interconnection of the hybrid power system elements. Researchers have accumulated and described in scientific papers extensive experience in designing, theoretical research, and numerical modeling of hybrid power plants with high-temperature SOFCs. It is shown that experimental hybrid power plants based on SOFCs of the megawatt class are in operation. Hybrid systems with an SOFC are designed only for the kilowatt power class. Trigeneration systems with a steam turbine exist only in the form of theoretical calculations. Trigeneration systems show the highest electrical efficiency, but the highest construction and service costs. Systems based on high-temperature SOFCs can be used for autonomous systems, and in combination with gas and steam turbines only at thermal power plants. Experimental laboratory studies are limited by the high cost of installations and the difficulties of testing the possibility of using combined heat and power systems on an industrial scale. Therefore, a more detailed study of the relationship between the units of a combined heat and power system is recommended in order to achieve the high efficiency indicators obtained from theoretical studies.

In the context of increasing demands for the reliability and efficiency of electrical complexes and systems, the problem of assessing and monitoring the technical condition (TC) of electrical equipment is becoming particularly relevant. This review is devoted to a comprehensive analysis of the factors affecting the performance of electrical equipment and modern methods for diagnosing its TC. The review article examines in detail the impact of various operational factors, including climatic conditions (temperature fluctuations, humidity, contamination) and electrical equipment operating modes. Special attention is paid to modern methods of technical diagnostics, such as thermographic diagnostics, vibration diagnostics, and chromatographic analysis of dissolved gases, which make it possible to identify defects and predict failures at early stages of their development. A significant part of the review is devoted to modern approaches to predicting the durability indicators of electrical equipment using mathematical modeling and neural networks. The advantages of a condition-based maintenance (CBM) and repair strategy, based on assessing the actual TC of the equipment, are analyzed in detail and compared with the strategy of scheduled preventive maintenance. This review particularly emphasizes the importance of integrating digital technologies, including the internet of things (IoT), digital twins (DT), and intelligent diagnostic monitoring systems, to create effective systems for predicting and managing TC. The review demonstrates that a comprehensive consideration of the actual TC of electrical equipment and its operating conditions can significantly increase the reliability of power systems, optimize maintenance and repair costs, and extend the service life of electrical equipment under various intensities of impacting operational factors.

The power output of photovoltaic modules operating under certain field conditions decreases over the time. The photovoltaic module degradation factor depends not only by the physical properties of the material but also by the change of parameters of the environment where the PV panels operate. The change of the PV modules degradation factor over the time reflects on the power output which is in a close relation with revenues from the purchased electricity produced by the modules.The process of PV modules degradation is a normal process accompanying the operation of the panels. This process is a result of increased losses in linear connections; increased relative humidity of the ambient air, and the process of moisture evaporation; limitation of possibilities of the p-n junction; and destruction of protective coating. The first above mentioned of losses generally depends on the local atmospheric conditions where the panels operate. At higher local values of the average temperature and relative humidity of the air the rate of degradation increases. An analysis about the degradation rate of the PV modules operating under specific field conditions here is made.

A notable development in photovoltaic (PV) technology, quantum dot solar cells (QDSCs), provides viable answers to the drawbacks of conventional silicon-based solar cells. Quantum dots (QDs) are tiny semiconductor particles with unique optical and electrical properties due to their quantum confinement, which allows for programmable bandgaps and broad-spectrum light absorption. This review explores the integration of QDs into various solar cell architectures, such as quantum dot-sensitized solar cells (QDSSCs), quantum dot heterojunction solar cells (QD-HJSCs), colloidal quantum dot solar cells (CQDSCs), and quantum dot-polymer hybrid solar cells (QD-PHSCs). Innovations in these areas have improved power conversion efficiency (PCE), stability, and scalability. Additionally, the commercial applications and market potential of QDSCs are discussed, focusing on building-integrated photovoltaics (BIPV) and portable solar technologies. Despite these advancements, challenges such as material stability, cost-effectiveness, and scalability remain, necessitating further research and development. The future of QDSCs will likely involve exploring non-toxic materials, improved encapsulation techniques, and developing hybrid devices that combine the strengths of different PV materials.