The data of the International Expert Community on Renewable Energy REN21 and the Institute of Environmental Technologies AEE INTEC (Austria) are presented. In 2020, the leadership of hydropower was noted (1170 GW; 4370 TW.h/year); in second place is wind energy (743 GW; 1743 TW.h/year); then solar energy (708 GW; 901 TW.h/year); bioenergy (602 TW.h/year); geothermal energy (14 GW; 94.7 TW.h/year). In heat generation, biomass energy is in the first place (4323 TW·h/year); solar thermal plants (501 GW; 407 TW.h/year); geothermal heat supply stations (108 GW; 284 TW.h/year). In Russia, as of 01.01.2021, the installed capacity and generation of electricity for all power plants in the country were respectively: 245.3 GW (100%) and 1047 TW.h/year (100%); including HPPs - 50 GW (20.38%), SPPs - 1.7 GW (0.7%) and 1.98 TW.h/year (0.8%); WPP - 1.03 GW (0.42%) and 1.38 TW.h/year (0.5%). The total installed capacity of renewable energy in the Russian Federation amounted to 52.73 GW (21.50%), electricity generation - 210.76 TW.h/year (20.1%) with the generation in 2020 by all power plants in Russia of 1047 TW.h /year (100%). The state of the Russian renewable energy market, the role of the government in its formation and regulation are described. The results of activities in 2020 of small hydropower (1182 MW), solar heat supply (70 MW), geothermal energy (electricity generation - 84 MW, 428 thousand MW.h/year; heat generation - 110 MW, 280 thousand MW•) are presented. h/year), BioPP - 65200 MW.h/year, biothermal generation - 29836 GW•h/year.

In 2020, the world's total installed capacity of generation units based on renewable energy sources (not including hydropower) amounted to about 1437 GW: over 651 GW and 627 GW of wind and solar power plants was installed respectively. The growing of the installed capacity of these distributed generators is a response to the increasing the power consumption, global environmental issues and has also become possible due to the development of technology in field of power semiconductor devices. However, on the way of large-scale implementation of distributed generators based on renewable energy sources, traditional electric power system meets new challenges to ensure the reliability and sustainability of new electric power systems with renewable energy sources. In particular, distributed generators change processes in the electric power system, impact to the parameters and power balance, change the magnitude and direction of power flow and short-circuit current, which determines the need to update the settings of the relay protection and automation systems of traditional electric power system and to coordinate their operation with automatic control systems of installed distributed generators. The above mentioned tasks form a number of scientific research directions, one of which is a task of determining optimal size and location of distributed generators. The main purpose of this optimization task is to reduce power losses, operating and total electricity cost, improve the voltage profile, etc. In addition, the correct and reasonable placement of distributed generators defines an effective planning of the operating modes of electric power system and power plants (especially based on renewable energy sources, the operating modes of which depend on weather conditions and can be sharply variable). The paper highlighted the impacts of distributed generators on power losses, the voltage level, maintaining the power balance and the possibility of participating in the frequency regulation, and short circuit current in power system. The optimization criteria, the main limiting conditions, as well as methods for solving this optimization problem are considered. This review will help the System operators and investing companies, especially in Russia, to form the main aim, objective function and constraints that will aid to meet their load demand at minimum cost choose from the options available for optimization of location and capacity of distributed generators.

Recently, the theme of the "green transition", in which the economic and commercial prospects of the hydrogen industry play a leading role, in the global energy industry has attracted special attention from business, government and scientific circles in many countries, which is associated with its predicted impact, incl. due to the climate agenda, to the economic, technological and geopolitical redistribution of the energy map of the world at the global and regional levels. Some slowdown in the "green transition" is expected due to the need to overcome the global energy crisis in the next two or three years, which may turn out to be more serious than the crisis of the 1970s of the last century which will require eliminating the shortage of traditional non-renewable energy resources in the near future. Nevertheless, the "green transition", in which hydrogen accents are intensifying, continues to be implemented, which will have a serious impact on the system of international and international economic relations in the world. Thanks to the financial support of the state and business, modern technologies of the entire hydrogen energy chain are actively developing; hydrogen markets are being formed in the conditions of inter-fuel competition, as well as hydrogen energy command centers at the global, regional, country and corporate levels.

In this work, we studied the process of synthesis of gaseous hydrogen, as well as silicon and silica nanoparticles under the action of intensive ultrasonic cavitation in a plasma discharge in a tetraethoxysilane medium.
It is shown that a new form of plasma discharge arising in a liquid in an intensive ultrasonic field above the cavitation threshold, characterized by a volumetric glow in the entire space between the electrodes and an increasing voltampere characteristic can be effectively used to initiate various physical and chemical processes. It was shown that ultrasonic action in combination with an electric discharge is capable of decomposing tetraethoxysilane molecules with the formation of hydrogen, carbon oxides, and also solid-phase products - silicon and silica nanoparticles.
Experiments on the production of hydrogen and nanoparticles were carried out on a special experimental setup for the implementation of a plasma discharge in liquid-phase media. The setup consists of an ultrasonic generator, a piezoceramic transducer, a discharge power source, a reaction chamber, and discharge electrodes.
The results of the analysis of gaseous reaction products by gas chromatography show that during the pyrolysis of liquid tetraethoxysilane, hydrogen is formed with a content of about 90% and carbon oxides. The synthesized silicon and silica nanoparticles were isolated and studied using the methods of physicochemical analysis - infrared spectroscopy, X-ray phase analysis and transmission electron microscopy to determine the composition, shape and size of nanoparticles.
The study of nanoparticles by electron microscopy showed that particles of a corner shape are obtained during synthesis. The size of the synthesized nanoparticles is 50–100 nm. It was also shown by electron microscopy that, upon aggregation, the particles do not become larger in size, but form compound associates. It is also important to note that the advantage of this method for the synthesis of nanoparticles is their activated surface, which has a high reactivity as a result of exposure to intense ultrasound.
The resulting nanoparticles and their agglomerates can also be used as functional materials, fillers, and components of composite materials.