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Abstract: The paper considers small solar installations, which are developed and created at the Institute of Materials Science of the Academy of Sciences of the Republic of Uzbekistan. The authors of the article operate a Large Solar Furnace with a thermal power of 1000 kW and have extensive experience in operating and building solar high-temperature furnaces. Small solar installations are simple, cheap and easy to operate.

This paper reports the distribution of impurities in polycrystalline silicon obtained through fivefold remelting in a solar furnace and shows that in practically all impurities (iron, calcium, aluminum, selenium, silver, etc.) it is of a periodic character according to the sample length. Such a material was found to have rather interesting properties, i.e., in the structures made of it with simple ohmic contacts, even during a small temperature effect and a rise in the current and voltage. Currently, one of the promising methods of the purification of metallurgical silicon is its purification in open air by means of beaming solar energy.

This paper considers the digitalization of electrical networks, the organization of remote control of the values and parameters of electrical energy, the creation of digital elements, devices and complexes for monitoring and managing power quality indicators based on Cloud Computing technology, the conversion of primary currents into signals in the form of secondary voltages, and also discusses management issues symmetrical quantities and parameters of these converters. In addition, a model of a three-phase AC converter with specific loads and analytical expressions for determining the output voltage of a three-phase AC converter with a specific load based on the configuration of this model are presented, a cloud computing algorithm for studying a three-phase AC converter, the characteristics of electrical loads are given, the dynamic characteristics of electromagnetic three-phase load current converters, graphs of magnetic fluxes and a three-phase current converter of specific loads, stabilization mode in the conversion system of electromagnetic converters of three-phase current in 0.02-0.03 seconds after being connected to the network under a special load, an algorithm for constructing dynamic characteristics and generating analytical expressions. Based on this information, conclusions were drawn about the cost and parameters of three-phase current electromagnetic converters.

The efficiency of a combined solar photothermal plant for electric and thermal energy generation has been evaluated with account for the daily variation of solar radiation and atmospheric temperature. It is shown that in the summer with the heat removal temperature 40°C it is possible to utilize additionally up to 50% of the solar radiation energy even in the absence of thermal insulation of receiver bottom.

Abstract The amount of household solid waste (HSW) has been significantly increasing due to a rapid population growth and economic development. HSW management is immensely sensitive and complicated problem not only in rapidly developing countries like Uzbekistan but also in developed countries with advanced economies.The accumulated waste has been causing a number of serious environmental problems such as release of the most dangerous greenhouse gases (CO2, N2O, CH4) in the atmosphere which misbalance radiation in a planet’s atmosphere causing a global warming. However, this waste can be friendly in terms of its potential to be used as energy source. HSW into energy conversion technologies has been playing a vital rolein order to successfully address global challenges suchas fossil fuel dependency, emission control and waste management issues.The most promising technology for conversions can be performed using thermochemical processes (e.g., pyrolysis or gasification).These thermochemical technologies can be used to convert solid waste into liquid and gaseous fuels, and this has already been studied sufficiently by other researchers. This article recommends a novel concept for intensification of value-added solid and liquid products recovery from HSW using hydrothermal carbonization and plasma treatment.

Optimal planning of short-term modes of power systems is a complex nonlinear programming problem with many simple, functional and integral constraints in the form of equalities and inequalities. Especially, the presence of integral constraints causes significant difficulties in solving of such problem. Since, under such constraints, the modes of power system in separate time intervals of the considered planning period become dependent on the values of the parameters in other intervals. Accordingly, it becomes impossible to obtain the optimal mode plan as the results of separate optimization for individual time intervals of the period under consideration. And the simultaneous solution of the problem for all time intervals of the planning period in the conditions of large power systems is associated with additional difficulties in ensuring the reliability of convergence of the iterative computational process. In this regard, the issues of improving the methods and algorithms for optimization of short-term modes of power systems containing thermal and large hydroelectric power plants with reservoirs, in which water consumption is regulated in the short-term planning period, remains as an important task. In this paper, we propose the effective algorithm for solving the problem under consideration, which makes it possible to quickly and reliably determine the optimal operating modes of the power system for the planned period. The results of research of effectiveness of this algorithm are presented on the example of optimal planning of daily mode of the power system, which contains two thermal and three hydraulic power plants..

The effect the linear dependence of recombination center density along the coordinate on photovoltaic cell parameters is analyzed. It is shown that an increase of the recombination centers’ density from an interface with a p-n junction in the direction of the rear contact causes the saturation current and reduces the open-circuit voltage, while a reduction of the recombination center density along the length of the base in the direction of the rear contact causes the open-circuit voltage.

Powder with grain size about 1 μm has been prepared from a mullite alloy (2SiO2 · 3Al2O3) containing 4.0 wt % of a ceramic, which converts the initial energy to pulsed infrared (IR) radiation. Photo-photon converters have been fabricated on the base of iron sheet of thickness 0.6 mm and the functional ceramic. It is shown that the use of the metal-ceramic photo-thermo-photon converter accelerates significantly the drying process and the energy transfer rate.

Since turning carbon neutral is regarded as a major macroeconomic agenda worldwide, this study examines whether financial globalization and good governance can help Brazil, Russia, India, China, South Africa, and Turkey in achieving carbon neutrality. Considering the period of analysis from 2000 to 2020 and utilizing robust econometric methods, it is observed that the environmental consequences vary across different components of financial globalization. In particular, the results validate the pollution haven hypothesis by confirming the carbon emission-boosting effect of de facto financial globalization indicators. In contrast, the pollution halo effect hypothesis is verified by the finding of the carbon emission-abating effect of de jure financial globalization indicators. Besides, promoting good governance is evidenced to impose carbon emission-mitigating impact in the long-run. The findings also authenticate the existence of the Environmental Kuznets Curve (EKC) hypothesis for the emerging countries of concern. Finally, for both the short and long runs, it is found that the non-renewable to renewable energy transition contributes to lower discharges of carbon dioxide, while urbanization results in the amplification of the carbon emission figures. Considering these critically important findings, it is necessary for these countries to impose restrictions on the influx of unclean foreign direct investment, facilitate and ease the investment process for foreign investors for investing in environment-friendly projects, promote good governance, and adopt green economic growth and sustainable urbanization policies by developing their respective renewable energy sectors.