The article presents an overview of studies of agrivoltaic systems based on various types of photovoltaic modules, which have significant potential for the production and use of green hydrogen. The prerequisites for the active and effective implementation of agrivoltaics and green hydrogen in the modern world are considered, successful examples of the use of photovoltaic converters in agriculture and the production of green hydrogen are described, a classification of agrivoltaic systems is presented. The main advantages and disadvantages of using photovoltaic modules in agriculture are shown using examples of open, greenhouse and closed agrivoltaic systems. Modern agricultural machines and autonomous robots that are used in agrivoltaic systems are presented, and the feasibility of using green hydrogen in such devices is substantiated.

The paper considers heat exchange at supercritical pressures of n-heptane in different positions of the pipe. Comparisons of the data obtained in experiments with the calculated ones are given. It is revealed that somewhat significant discrepancies between the experimental and calculated values of the Nusselt criterion are observed in the region of the secondary improved heat transfer mode, where with an insignificant increase in the heat flux density as a result of the influence of the combined actions of various factors, a decrease in the wall temperature of about 150 °C and more occurs. At the same time, the calculated values of the Nusselt criterion in a number of cases are approximately 25% less than the experimental ones.
As a result of the analysis of experimental data, it was established that, regardless of the direction of fluid flow and the position of the pipe under conditions tc ≈ tm and tc ˃ tm, the temperature of the cooled surface along the length of the pipe The pipe is distributed nonlinearly – in the middle part of it x/d ≈ 60 there are pronounced temperature maxima of the walls.

The task of the study was to determine the maximum possible efficiency of thermal hybrid solar collectors when used in the south of Siberia. To do this, the nodal points and the efficiency of the organic Rankine cycle were calculated at the temperatures of the photovoltaic panel equal to 25 °C, 50 °C, 75 °C and 100 °C, plots of the dependence of the efficiency of the photovoltaic panel, the efficiency of the organic Rankine cycle and the efficiency of the thermal hybrid solar collector on temperature of the photovoltaic panel. The efficiency of the organic Rankine cycle at PV panel temperatures of 25 °C, 50 °C, 75 °C and 100 °C is 5,3%, 11,5%, 16,8% and 21,3%, respectively. The efficiency of a photovoltaic panel at its temperatures of 25 °C, 50 °C, 75 °C and 100 °C is 17%, 14,9%, 12,8% and 10,6%, respectively. The efficiency of a thermal hybrid solar collector at PV panel temperatures of 25 °C, 50 °C, 75 °C and 100 °C is 22,3%, 26,4%, 29,6% and 31,9%, respectively. The article substantiates the choice of ammonia (R717) as a low-boiling working fluid in the organic Rankine cycle. It is shown that the maximum possible efficiency of a thermal hybrid solar collector, equal to 31,9%, is achieved at a photovoltaic panel temperature of 100 °C. Based on the results of the work, it was concluded that the maximum possible amount of energy that can be obtained per year in Novosibirsk from 1 m² of a thermal hybrid solar collector following the sun is 856,5 kW·h; the maximum possible amount of energy that can be obtained per year in Novosibirsk from 1 m² of a stationary thermal hybrid solar collector is 585,4 kW·h.

The paper studies various parameters of films of amorphous and nanocrystalline silicon-carbon alloy (a-nc-Si_1-xC_x:H (x = 0-1)) doped with phosphorus (PH₃) and boron (B₂H₆). The properties of these films obtained on various substrates of quartz, glass and silicon with a coating of Fe, Al, Pd, Ni, Ti, Ag, are studied. The morphology of the obtained nanotubes is studied using transmission electron microscopy (TEM). The structural properties of the films were also studied using infrared spectroscopy and X-ray diffraction. Cascade solar cells with an area of S = 1,0 cm² and an efficiency of 14,09% were created.

The synthesis of a ZnO metal oxide film on the surface of KDB-20 silicon was carried out. It was determined that the crystallographic direction of the used silicon has the (100) orientation. The optimal conditions for obtaining thin ZnO films have been determined by the method of spray pyrolysis of the sol-gel technology. It was found that ZnO metal oxide films have a hexagonal system and a wurtzite crystal structure with the parameters a = 0,4989 nm and c = 0,8342 nm, with the nanocrystallite size of 67 nm. Investigation of the current-voltage characteristics (CVC) of n-ZnO/p-Si heterostructures at illumination E = 0 Lx and E = 1000 Lx and it was determined that the forward branch of the I-V characteristic has an exponential interval of current versus voltage. The effect of the concentration of deep impurities on the exponential section of the current-voltage characteristic has been studied. The results obtained are interpreted within the framework of the theory of the effect of injection depletion of carriers of the p-n junction. The photoluminescence spectrum of the n-ZnO/p-Si heterojunction has a maximum at λ_max = 377 nm and covers a wide band in the optical range. This makes it possible to determine the most optimal regime for growing the ordered structure of the ZnO film on the silicon surface, which ensures growth with practically no defect structure. Experimentally synthesized heterostructures can be used in solar energy and optoelectronics as photodetectors. New possibilities of using the n-ZnO metal oxide film in photovoltaic converters are indicated. The technology for producing films is environmentally friendly, affordable and economically viable, and seem promising for their application in the detection of visible and ultraviolet light.

In the modern conditions of increasing requirements for energy efficiency and environmental sustainability of energy systems, special attention is paid to the integration of renewable energy sources. This article examines the optimization of hydroelectric power plants (HPPs) and reservoirs using wind energy using the example of the Chortok district of the Namangan region. Methods for increasing the stability of energy supplies through the combined use of water and wind resources, as well as compensating for fluctuations in electricity generation are considered.

The study showed that one of the key problems of operating HPPs in this region is the need to give significant volumes of water for irrigation in the summer. This limits the ability of HPPs to stabilize energy production, since water resources become insufficient to maintain the required level of electricity generation. In this regard, wind energy, as an additional source, plays an important role in compensating for seasonal fluctuations and maintaining stability of energy supply throughout the year. However, wind stability is also subject to seasonal factors, which requires a special approach to management.

On the contrary, the operation of HPPs in winter is stabilized due to lower requirements for water consumption, which allows maintaining a relatively constant level of energy generation. The article analyzes the possibility of efficient use of wind energy in winter, when hydro resources are most accessible for stabilizing the overall power supply system.The presented results demonstrate that the integration of wind energy with water resources allows to minimize the negative effects of seasonal fluctuations, providing a more reliable and environmentally sustainable energy system.

Computational fluid dynamics (CFD) methods were used to analyze the flow around two sequentially arranged bodies. A comparative assessment was conducted to determine the conditions under which hydrodynamic instability may occur in low-concentration gas-dispersed flows. Variations in the physical properties of particles, typical of those found in industrial biomass and fossil fuel energy installations, were considered in this assessment. The numerical model for laminar flow around individual particles was validated using the experimental data of Rowe and Henwood for dimensionless intersphere distance of 5, 11, 17, and 23. It was demonstrated that the velocity profile upstream of the first sphere influences the ratio of forces acting on each sphere. The critical dimensionless center-to-center distance (x/d)_кр was calculated, at which the ratio of the force acting on the second particle (F₂) to that on the first particle (F₁) equals 0,95 (indicating the onset of convergence), under steady uniform gas flow conditions in an elemental streamtube of an ideal entrained-flow reactor for particles of spherical and plate-like shapes. Within the Reynolds number range 2,0·10^-1…3,2·10³, the influence of particle density, size, and shape on the corresponding critical volume concentration φ_кр and (x/d)_кр was determined. Additionally, for spheres, the force ratio F₂/F₁ = 0,90 was considered, which allowed to establish the transition zone between entrained-flow systems and circulating fluidized bed (CFB) boilers. Simulations of gas flow around two plates with three different orientations relative to the incoming flow were conducted. The results demonstrate that the mutual orientation of plate-like particles in the flow affects their hydrodynamic interaction. Specifically, compared to the scenario of flow around two spheres of equivalent diameter, the risk of convergence increases when the particles are oriented with their largest face perpendicular to the incoming flow, and decreases when they are oriented with their smallest face perpendicular to the incoming flow. The effectiveness of the proposed method was verified by analyzing a range of systems, including power boilers, industrial gasifiers, and large-scale test installations.

The article discusses the prospects of using Sosnovsky’s burshevik in the production of bioethanol as a method of disposal of an invasive culture. The article explains the benefits of hogweed based on its biological characteristics and the possibility of using food alcohol production technologies to process raw materials into various types of useful substances.

Alternative applications of hogweed are given not only in the field of energy, but also in pharmacology, the pulp and paper industry, the perfume industry and agriculture.

Microalgae have long attracted the attention of researchers due to their ability to capture carbon from the atmosphere and convert it into organic compounds. Understanding how microalgae species respond to different conditions is important for the development of efficient biotechnological carbon dioxide capture systems that can be a sustainable solution in the context of global climate change. The study determined the effect of temperature, nutrient medium composition and aeration on the process of carbon dioxide absorption by Chlorella kessleri microalgae, and compared the carbon dioxide absorption rate with Chlamydomonas sp., Chloromonas typhlos. The optimal conditions for carbon dioxide absorption by Chlorella kessleri microalgae are: temperature –30 °С, illumination – 3000 lx, aeration, the presence of nitrogen compounds in the nutrient medium. Under such external conditions, the maximum carbon dioxide absorption rate (0,187 g · L^-1 · day^-1) is achieved by this type of microalgae. Lack of aeration and nitrogen deficiency negatively affect the process of CO₂ absorption and reduce its absorption rate to 0,042 g · L^-1 · day ^-1.

This work is dedicated to an analytical review of various aspects related to carbon dioxide utilization. The study examines different methods of carbon dioxide capture currently available. The most promising method of carbon dioxide utilization is the use of microalgae. This is primarily due to the cultivation conditions of microalgae, particularly their ability to grow in various environments that do not compete with agricultural crops. Additionally, the following advantages of microalgae in the context of carbon dioxide utilization are highlighted: rapid biomass accumulation, species diversity, oxygen release during photosynthesis, and high absorption capacity. It has been established that certain factors influence the carbon dioxide utilization process, including photoperiod, light intensity, cultivation temperature, medium acidity, concentration of supplied carbon dioxide, and various additives to the nutrient medium. As a result, optimal conditions were determined for most types of microalgae, under which the carbon dioxide capture process is most efficient. The optimal conditions for effective CO₂ capture by microalgae are as follows: maintaining a photoperiod of 16 hours of light/8 hours of darkness, light intensity of approximately 5405 lux, temperature range of 20 °C-25 °C, medium acidity between 6 and 8,3, carbon dioxide concentrations up to 5%, and the addition of urea and sodium bicarbonate to the nutrient medium. The practical significance of this work lies in the potential for implementing this technology in various industries across all energy sectors in the Russian Federation. It is proposed to use the absorption capacity of microalgae to reduce the environmental impact of thermal energy carriers. Further research in this area will enable the development of an efficient carbon dioxide capture system that produces a value-added product (microalgal biomass), making this research economically attractive for continued investigation.

This paper discusses the optimization of the Sieverts-type apparatus with the goal of achieving precise measurements of the interaction between hydrogen and materials using volumetric methods. In order to obtain accurate and reliable measurements of sorption and desorption kinetics in hydrogen storage materials, it is important to reduce the effects of temperature gradients within the Sieverts-type apparatus. Two methods were developed to minimize the impact of temperature gradients on hydrogen measurements. The first method involved segmenting the gas path and measuring the temperature in each section. The second method utilized the total volume of the gas path, divided into two dynamic volumes for hot and cold sections. Experimental equations were derived to calculate the hydrogen content, taking into account the effects of temperature gradient, for both methods. These methods were then implemented, and the results were compared. The most successful result was obtained using the second method, with the maximum deviation of 0,1% of the initial gas volume.

The article presents an experimental and theoretical study of the optical properties of tin oxide thin films. It is in thin films that the adsorption of gas molecules has a greater effect on the conductivity of the layers. The method of measurement using a spectrophotometer and further processing of experimental optical transmission spectra is presented. Transmission spectra were measured, from which the band gap width was determined.

Tin oxide films made by spray pyrolysis from a sol-gel solution were studied, and the structural properties of tin oxide were also considered. The experiment was conducted as follows. Two-aqueous tin chloride (SnCl₂ = 2H₂O) (0,5 M) is used as a precursor, isopropyl alcohol was used as a solvent. The solution was stirred for 1 hour, followed by 24 hours of exposure. The application of spray pyrolysis of SnO₂ was carried out on the basis of a solution for the sol-gel method (SPGZ). To do this, the solution was filled into the tank of the automated spray pyrolysis unit USP-3. Optical properties were studied using a spectrophotometer SPECKS SSP-715-M spectrophotometer manufactured by JSC LOMO. It was revealed that the films have a transparency of T = 60-80% in the visible range of the spectrum. The optical properties of tin oxide films at temperatures of 200, 300, 400 °C are presented. The width of the forbidden zone, which is the value at a temperature of 200 °C – 3,96 eV, 300 °C – 3,98 eV, 400 °C – 3,98 eV.

The paper provides an in-depth exploration of the theoretical framework underpinning the enhancement of sorption capacity in materials derived from agricultural waste through the revolutionary technique of 3D treatment within a lowpressure radio frequency discharge plasma environment. It undertakes a rigorous examination, offering a comprehensive exposition of the intricate physical and mathematical models governing the multifaceted interaction dynamics between low-pressure radio frequency (LP-RF) plasma and capillary porous biopolymers. By employing sophisticated mathematical modeling methodologies, the study meticulously dissects and elucidates the complex processes involved in orchestrating structural modifications across the supramolecular landscape of these materials throughout their entire volume during plasma treatment. This exhaustive theoretical inquiry not only enables the discernment and elucidation of pivotal mechanisms responsible for inducing structural transformations but also unveils the intricate interplay of various factors influencing the ultimate enhancement of sorption properties in agricultural waste-based materials.

This article discusses the ventilation mode of underground buildings, and comparatively analyzes the thermal insulation performance of above ground and underground buildings in different seasons. At the same time, the article proposes three kinds of heating solutions applicable to underground buildings, and analyzes their advantages and disadvantages in detail, providing a more ideal choice for the energy-saving design of underground buildings.