The paper concerns technologies of alternative energy, in particular, solar energy. The research discusses the results change in optical parameters of silicon plates influences due to ultrasonic machining. For experiments, the crystalline con plates of p-type of the conductivity are used for solar cells manufacturing are chosen. We have made ultrasonic chining of a surface of silicon plates by means of the special device. The device consists of the mainframe of mechanl influence, the air compressor and the of ultrasonic frequency generator. The mainframe of mechanical influence is pplied by system of adjustment of air pressure, a vibrator, working cylinders of mechanical vibration transmission, a herical micro-probe from firm metal, the channel of pressure transfer upon the vibrator. The roughness of a surface and factor of  reflexing from a surface depending on length of a wave of an incident ht before and after machining are measured. On the basis of LSM-images received and an estimation of roughness d also measurements of light reflexing factor, the surface texturing mechanism which can be used for production of gh effective solar cells is offered. Moreover, we have researched the influence of ultrasonic machining of a surface silicon plates for life period of the minority charge carriers in silicon plates before processing by means of the spel device. For measurement of life time of minority charge carriers in silicon plates before machining, we have emoyed the method of quasi-stationary photoconductivity based on contactless measurement of conductivity of a plate influence of pulse radiation allowing to spend an estimation of sizes of effective life time of minority charge carri. The received experimental results, physical interpretation of processes of light absorption in the plates subjected ultrasonic machining and change of life time of the photo-generated carriers of a charge allow us to recommend a w way of increase of silicon solar cells efficiency.

The article is devoted to the tasks of forecasting the productivity of solar power plants (SPP) and PV-unit. A review of modern forecasting methods and the actual basis for its implementation is made. Accepted classifications of methods are presented, the basis of which is the “direct forecasts - indirect forecasts” approach. The basis of the second approach is the forecast of solar radiation with subsequent conversion to the productivity of solar power plants. Accordingly, in the first case, a series of data on plants productivity over long periods in the past are of great importance and mainly statistical and machine learning methods are used. The second approach is based on a numerical weather forecast, which provides, among other things, a solar radiation forecast. A significant influence on the choice of forecasting methods is provided by the required spatial and temporal horizon. The latter is determined by the electricity market rules in a particular country or region. The problem of spatial resolution is important for power plants occupying large areas, as well as in forecasting the productivity of a network of solar plants. The article presents the currently adopted forecast metrics which allow estimating errors, as well as comparing the effectiveness of various forecasting methods. The prospects of developing probabilistic forecasts as an alternative to deterministic approaches are shown. Probabilistic forecasts are more likely to meet network requirements. The requirements of grid operators in some countries for forecasting the productivity of SPP and the penalties in case of a high forecast error are considered in the article. Examples of financial losses from forecast errors are shown on the example of solar power plants in the USA and China. The requirements of the Russian Federation wholesale energy and capacity market are discussed. The market sets the maximum permissible deviations from the declared energy production by stations (including SPP) and fines for these deviations. The article presents the financial  losses estimates from errors in productivity forecasts for solar energy plants in the Russian Federation.

This article reflects the development of the project “Web Atlas of the Available Wave and Wind Energy of the Coastal Zone of the Russian Seas”. The Atlas includes the waters and coasts of the Black, Azov, Caspian, Baltic, White, Barents, Kara and Okhotsk seas. In order to compile the atlas, we have used the results of calculating the parameters of wind waves, including the magnitude and direction of the energy flow. Wind speed data is obtained from high-resolution reanalyses. The web atlas is based on the classic three-tier model, which includes a data storage subsystem (database server), a data analysis and publishing subsystem (GIS server), and a web-application subsystem that provides a user interface for interacting with data and map services (web server). The article presents the results of the web atlas development second stage. At this stage, we have solved the tasks of supplementing the databases and developing the cartographic web interface, which made it possible to access the information loaded into the database, visualize the wave and wind parameters, calculate the main statistical characteristics, and plot the time series of data in points.

The paper discusses the features of flows inside orthogonal turbines that determine their low efficiency. Proposals are formulated that increase the efficiency of turbines. It is noted that multilevel turbines with one or two fixed blades in each tier, as well as turbines with one spiral blade, are the most effective in unlimited flow. The paper suggests the results of calculations and laboratory tests for optimizing turbines and new proposals for the use of automated flaps on the blades.

The use of hydrogen as an energy carrier in the energy sector is associated with the possibility of increasing the efficiency of generating capacities, in particular nuclear power plants, through the overheating of the steam of a steam-turbine cycle. In this case, the high-temperature steam obtained from the combustion of hydrogen with oxygen is mixed with the steam of the steam turbine cycle. Taking into account the works of the other authors, this paper performs a wide range of studies to increase the efficiency and competitiveness of nuclear power plants due to steamhydrogen overheating of the steam of the steam-turbine cycle under conditions of hydrogen production by electrolysis of water due to inexpensive night-time electricity from the NPP. An important role is played by the efficient burning of hydrogen with oxygen. In this regard, the paper for the first time studies the composition of the resulting steam without using mixing with a cooling component. The paper presents experimental data on the unreacted hydrogen proportion during its combustion with oxygen without mixing the resulting steam with a cooling component – steam or water. Moreover, the paper presents the experimental setup developed together with the United Institute for High Temperatures of RAS and allowing the selection of steam for chemical analysis by means of a chromatograph. The results of experimental measurements of the main parameters of the process of burning hydrogen in oxygen with a stoichiometric flow of hydrogen and oxygen, as well as with an excess of oxygen equal to 2, are presented. The theoretical calculation method defines the temperature of the resulting steam along the length of the flame tube of the experimental setup, including at the ignition point. Due to chemical analysis of steam, the unreacted hydrogen proportion at the initial stage of hydrogen combustion is determined. The effect of an excess of oxidizing agent on the initial and final content of unreacted hydrogen in the vapor is shown. The methodology of determining the time of steam movement inside the flame tube of the experimental setup is presented. In this regard, the paper for the first time studies the composition of the resulting steam without using mixing with a cooling component.

This work carries out  the experimental studies on the hydrogen  production using intensive hydrodynamic cavitation in liquid hydrocarbons. The physical and chemical processes occurring in the cavitation bubble at the last stage of its compression are very similar to the processes occurring in the explosive chamber. The values of pressure and temperature achieved in this case provides the thermodynamic stability of the reaction products and the production of a gaseous mixture (aerosol) of hydrogen and carbon nanoclusters, which is confirmed by theoretical calculations. The controlled addition of hydrogen-containing liquids and the change in the compression conditions of cavitation bubbles make it possible to control the process of hydrogen synthesis, which is an important step in the development of modern high-tech alternative energy methods. The pulsation of a spherical cavity is described by the Kirkwood – Bethe equations, which are one of the most accurate mathematical models of pulsation processes at an arbitrary velocity of the cavity boundary. The model allows you to fully describe the process of pulsations of cavitation cavities, conduct comprehensive parametric studies and evaluate the effect of various process parameters on the collapse of cavities. This work continues the experiments on cavitation synthesis of carbon nanostructures. With the rapid movement of chemically pure benzene (С6H6) along the profiled channel in the form of a Venturi nozzle, cavitation bubbles form in the liquid, which are then compressed in the working chamber, in which a sharp pressure surge is created. The pressure in the shock wave, which reaches 80–90 MPa, ensures the collapse of cavitation bubbles close to adiabatic compression. As a result of the number of rapidly occurring physicochemical processes of evaporation, heating, and thermal dissociation of benzene vapors, a solid carbon phase and a gaseous hydrogen-containing phase are synthesized in the cavitation, which is then subjected to separation.

At present, hydrogen energy is gaining immense popularity in the world due to the problem of depletion of nonrenewable energy sources, hydrocarbons, and environmental pollution caused by their growing consumption. Compared with electro- or thermochemical processes, the biological production of hydrogen has a number of advantages associated with greater environmental friendliness and low cost. Of particular interest is the dark process of producing hydrogen-containing biogas in the processing of organic waste under anaerobic conditions which allows you to take advantage of both energy production and solving the problem of recycling organic waste. This paper considers the production of biohydrogen in a two-stage process of anaerobic bioconversion of organic matter of liquid organic waste. Moreover, experimental studies were carried out continuously in reactors with increased volume. The article describes an experimental setup for investigating a two-stage process of anaerobic bioconversion of organic matter of liquid organic waste and setting up an experiment to study the effect of recycling the effluent of methantenk into an anaerobic bioreactor for the production of biohydrogen. The obtained experimental data on the specific yield of biohydrogen are consistent with the data obtained by other authors. The average specific yield of biohydrogen (per kilogram of initial organic matter) during recycling of the methantenk effluent increased by 4 % (from 0.1046 to 0.1087 m3 / (day * kg of OMin)). In addition, recycling of the methantenk effluent to the biohydrogen production reactor during two-stage anaerobic bioconversion allows us to reduce fluctuations in the output of biohydrogen from the reactor. At the same time, there is no methanogenic activity in the anaerobic bioreactor for the production of biohydrogen. The self-stabilizing pH level in the anaerobic bioreactor for producing biohydrogen is less than 4.5 (3.94 without effluent recirculation and 3.88 with recirculation), however, there is no inhibition of hydrogen formation. Thus, the use of recirculation of the methantenk effluent into the anaerobic bioreactor for producing biohydrogen can enhance the efficiency of the two-stage anaerobic bioconversion of organic waste while maintaining the stability of the process.

The paper considers the various types of bipolar elements and materials which are used for their manufacture in fuel cell technology. They play an important role in switching individual fuel cells in a battery, and make up the largest fraction of its mass (up to 80%), which affects the specific mass power characteristics of the power system. Bipolar cells based on thin titanium foil and a corrugated duct have high mechanical strength with minimum weight, are important elements of a fuel cell battery, and their use can significantly improve the mass specific characteristics of a power system based on fuel cells with a solid polymer electrolyte and direct air supply. Protective coatings should provide low-resistance contact when switching individual fuel cells and prevent its change during prolonged operation of the fuel cell. Coating in a magnetron setup allows preliminary coatings on large surfaces to produce thin coatings with reproducible composition and properties. For research, we have used graphite and platinum targets, as well as composite graphite targets with platinum inserts in the spray zone. Using generally accepted procedures, we have studied the influence of the composition and conditions of applying composite coatings on the corrosion resistance and surface contact resistance of bipolar elements. The use of a graphite target and segments made of platinum is shown to allow obtaining protective coatings close to the requirements of technical targets for coatings in terms of corrosion resistance and surface contact resistance. Such titanium coatings have better conductive and protective properties than thin-film coatings based on platinum and thin films of gold. The production of protective coatings based on titanium carbides have a high surface resistance, and based on titanium nitride – lower protective properties. Thus, magnetron technology can be recommended as industrial for the production of bipolar elements.

In Azerbaijan, as in the whole world, the influence of global warming on the environment, including individual ecosystems, and various sectors of the economy is observed. It was emphasized that a comprehensive study of the nature of global and regional climate changes and their impact on ecosystems and habitats, the identification of appropriate diagnostic and prognostic relationships, the development of recommendations and proposals, and the conduct of fundamental and applied research in the field of bioclimatic and environmental processes are the subject of research by scientists and experts of many countries. Ecological systems and their components that are most susceptible to climatic anomalies include, in particular, forests. Forest ecosystems, being part of the biosphere, play an important role in its protection, development and selfregulation, in the formation of the habitat, in the production of various products, and in the prevention of environmental pollution. The article notes that global warming also leads to an increase in the probability of forest fires. The influence of climatic changes on forest ecosystems of the northeastern slope of the Lesser Caucasus was studied and, based on statistical data, the frequency of forest fires was assessed according to the degree of danger. For the first time, spatial and temporal patterns were identified with respect to the northeastern slope of the Lesser Caucasus, a geographical generalization of the horizontal and vertical distribution of climatic parameters was carried out, their features and quantitative variability, geographical vertical distribution of climatic parameters, regional climate change, and the risk of fires in forest ecosystems, the recurrence of periods of drought, the influence of the habitat on bioclimatic parameters. In addition, the trend of variability in the daily precipitation intensity index was estimated. We have determined the period of time during which the maximum values of the absolute maximum and minimum temperatures are observed, which are indicators of extreme weather conditions, as well as the number of days when the maximum temperature exceeds 30 °C.