The main parameter to ensure the optimal operation of the photovoltaic system is to determine its position of this system in accordance with the available solar radiation in the location. Nevertheless, in order to predict the performance of a photovoltaic system, it is important to know the ambient temperature, since the temperature of solar cells affects the output parameters of the system, which is expressed in temperature coefficients. Thus, it is possible to optimize the operation of the photovoltaic system by varying the temperature of the elements using design solutions such as a heat sink or photothermal conversion system.

The article demonstrates the operation of own development installation for measuring the parameters of solar cells. The results of measurements to determine the temperature coefficients of thin-film elements using this installation are presented. For comparison, we have measured the output parameters of a monocrystalline modules and thin-film photovoltaic modules (PM) based on amorphous silicon, CdTe, and CIGS at various temperatures from 20 to 80 °C.

The changes in the output power of PMs at various operating temperatures are calculated in comparison with the values under standard testing conditions (STC). The parameters measured at various temperatures are normalized to STC. The temperature dependences of the normalized values of the maximum output power, fill factor, short circuit current, and open circuit voltage are presented. Decrease in the open circuit voltage is observed with an increase in temperature in all modules. The sharpest decrease in the fill factor with increasing temperature is observed in the monocrystalline module, in combination with a decrease in open-circuit voltage, it showed the biggest decrease in output power, 15.9%, 20.4% and 25.1% at temperatures of 60 °C, 70 °C and 80 °C, respectively. It is proved that all PMs based on thin-film technologies have smaller values of the temperature coefficient of the output power in comparison with a monocrystalline modules, the smallest of which is for CdTe.

The further tasks are set to develop hardware and software for improvement of the installation to provide the dynamic changes in the intensity of illumination, temperature and wind speed defined by a program.

The article deals with the problem of energy supply to remote northern territories on the example of the Solovetsky Archipelago. In the Russian Arctic, there are a large number of remote settlements that are not connected to the centralized power supply system. The power supply of these areas is most often carried out by low-capacity power plants on diesel fuel. Electricity generation from diesel is very expensive because the fuel needs to be shipped over long distances. In addition, there is a risk of spills and fuel leaks during transportation. The article considers the possibility of using own energy resources of the island, in particular wind energy, as one of the solutions to these problems. Wood fuel cannot be used on the islands, as deforestation is prohibited in the archipelago.

The wind power potential of the Solovetsky Archipelago is investigated to confirm the possibility of using wind energy. Weather data on wind speed and wind direction is analyzed for the period from 2000 to 2017 for a height of 50 m. NASA Langley Research Center data are used. As a result of data analysis for 18 years, a wind rose is built. During the study, modeling of the operation of the wind park and calculation of the annual energy production are carried out with WindSim software. WindSim uses computational fluid dynamics to optimize the placement of wind power plants on shore and offshore power plants.

As a result of the study, the annual energy production of wind parks located in different parts of the island is calculated. Three wake models are tested to understand the effect of the location of the wind turbines relative to each other on the annual energy production. The loss for the selected location is found to reach 9.9%. As a result of comparing the annual energy production of the wind park in summer and winter, in winter the productivity is found to be higher than in summer, which is important when the wind park is operated in northern conditions. This case study will encourage the implementation of renewable wind energy technologies in remote islands in the Arctic region.

Despite the dominance of hydrocarbon fuel in the fuel and energy complex of the world and particularly in Russia, there is a research interest in the field of biofuels from various types of biomass. These works are relevant both from the point of view of obtaining fundamental knowledge and the development of technologies, as well as the search for conditions for cost-effective production of biofuels using various biomass processing technologies. In the article, microalgae are considered as a source of biomass for producing fuel.

Nowadays a number of methods for the conversion of microalgae to biofuels (biodiesel, bioethanol, biobutanol, bio-oil, biochar, biomethane, biohydrogen, etc.) have been developed and tested. One of the problems of these technologies is the high humidity of the microalgae biomass, which requires a significant expenditure of energy for drying before processing the biomass into fuel. In addition, in the case of the production of biofuels (for example, biodiesel) only the lipid part of the biomass is converted, while the remaining raw materials, including proteins and carbohydrates, are not involved in the production of biofuels. Due to this fact, in recent years, the technology of hydrothermal liquefaction (HTL) has been applied to microalgae, which does not require drying of biomass, and, therefore, provides lower production costs.

In order to increase the economic attractiveness of biofuels, great importance is given for obtaining associated target products that provide additional profit. For the same purposes, they conduct a territorial analysis and search for sites for production facilities, where the cultivation and processing of microalgae requires minimal costs. In this work, we have analyzed the influence of regional, climatic and infrastructural factors on the production and integrated use of microalgae biomass. The microalgae Arthrospira platensis and Dunaliella salina are chosen as the object of research, and the Republic of Dagestan is chosen as the research region due to favourable climatic conditions and the availability of resources for the cultivation of microalgae (sea water as a source of macro- and microelements, geothermal deposits as a low-temperature heat source, cement plants and thermal power plants as a source of CO2). As a result the article presents a map of the areas that are potentially suitable for the production of biofuel and associated target products from microalgae and their estimated productivity.

The article substantiates the actuality of providing NPPs with basic electric load in the conditions of increasing their share in the structure of power systems. In this regard, as an alternative way to using the pumped storage power plant (PSPP), on the basis of the scientific base of the authors of the article, schemes for combining the hydrogen facility with nuclear power plants with justification for their effectiveness are given. These are combination schemes in which the steam obtained from burning hydrogen with oxygen is mixed with the steam of the steam turbine cycle of a nuclear power plant and overheats it. At the same time, peak power generation at NPPs when combined with the hydrogen facility is efficiently possible when using steam-hydrogen overheating of fresh steam through the use of a two-stage hydrogen-oxygen combustion chamber installed in front of the high pressure cylinder of the steam turbine. A variant is possible with the installation of a constantly operating low capacity additional steam turbine, which, along with obtaining additional peak power, can improve the reliability of power supply for the needs of nuclear power plants in conditions of major system emergency with disconnect due to the use of steam obtained from residual heat in reactors. A new combination scheme based on a closed hydrogen cycle has been developed in which the steam initially obtained from hydrogen combustion additionally heats the feed water before entering the steam generator and then overheats the steam of the steam turbine cycle of the nuclear power plant in front of the turbine without mixing due to the use of heat-exchange heating surfaces. In the scheme provides a catalytic afterburner of unreacted hydrogen. The systemic efficiency of the newly developed scheme is investigated. Initial data and a methodology for provide equal supply of peak electricity at compared with the PSPP are given. The results of evaluating the effectiveness of additional heating of feed water and overheating of fresh steam in front of the turbine are presented. It is shown that the use of most of the heat from the combustion of hydrogen for the initial overheating of fresh steam is thermodynamically more effectively, since it reduces the cost of replacement power at compared with the PSPP. The results of the net present value evaluation in the compared variants are presented. The variant of the hydrogen facility with the lowest cost of replacement power is shown to compete with the PSPP at its specific investment of $ 660 / kW. PSPP options with a specific investment of more than $ 660 / kW are not competitive with the hydrogen facility.

The article discusses the issues of technical and economic efficiency of combustion hydrogen with excess oxidizer when combining NPPs with a hydrogen energy complex based on a closed hydrogen cycle. Combustion hydrogen fuel with an excess of oxidizer allows minimizing the underburning of hydrogen fuel and increasing the efficiency of the hydrogen cycle. Using this approach, a safe and effective increase in the efficiency and power of NPPs is ensured by increasing the temperature of the steam in the cycle of the steam turbine unit by combustion hydrogen fuel in oxygen. Increasing the efficiency of hydrogen cycles at NPPs ensures the further development of environmentally friendly energy based on nuclear-hydrogen technologies and the possibility of efficient loading of NPPs in condition of an uneven schedule of power consumption in the country's energy systems. The authors of the article have conducted a study of the technical and economic efficiency of combustion hydrogen with an excess of oxidizer based on a closed hydrogen cycle.

The effectiveness of the scheme for combining NPPs with a hydrogen cycle using a closed system for combustion hydrogen with an excess of oxidizer has been evaluated. This approach allows the safe use of the heat of hydrogen fuel to increase the parameters of fresh steam of steam turbine unit. It is shown that the implementation of the scheme with an excess of oxidizer makes it possible to exclude the preliminary cooling system of the comb ustion products, which makes it possible to more efficiently use the heat of hydrogen fuel due to a more significant increase in the temperature of fresh steam and the corresponding increase in the power of steam turbine unit.

We have obtained the main indicators of comparative technical and economic efficiency of the proposed scheme for combining NPPs with a hydrogen energy complex based on a closed cycle of hydrogen combustion with an excess of oxidizer. It is shown that the cost of production of additional electricity is competitive in comparison with the scheme of pre-cooling of combustion products. At the same time, the calculation of the accumulated net present value shows the effectiveness of the proposed scheme for hydrogen overheating of steam at NP Ps, taking into account the possible savings of natural gas in the power system. The results can be used in the development of systems for increasing the maneuverability of NPPs.

In Russia, the developing new safe and non-waste technologies for processing waste is an complex issue, in particular for development of the Arctic. This problem can be solved with the help of hydrogen electric power technologies. The article analyzes the structure and method of waste-free technologies of waste processing. The waste is divided into: the most common solid waste industry and life, including natural and man-made factors (landfills); liquid waste including sewage sludge household and rainwater, oil and other industrial waste; leachate landfills, including landfill gases; waste during transportation and transshipment of oil products, etc. The methods of purification and industrial shipping equipment and their characteristics for the application at facilities of the Arctic are described. These installations include: incinerators, installations for treatment of sewage and filtrate of sewage of MSW, desalination plants of reverse osmosis and with use of snow and ice melting installations, cleaning and filtration of flue gases with an emphasis on methods of electric cleaning, standers for loading and unloading of oil products and hazardous waste. The article shows the advantages of the use of hydrogen sources and energy storage using LNG in the Arctic both in terms of energy efficiency and ecology, the possibility of their use in conjunction with the above waste treatment plants. The characteristics of solid oxide and solid polymer fuel cells and their applications are presented. For the most dynamically developing solid oxide cells, the article gives their characteristics in simple and cogeneration cycles and presents the scope of their application in small and distributed energy at power up to 10 kW. The characteristics of traditional sources of electricity on the basis of ship and aircraft gas turbine units operating on LNG, which can be used in Autonomous power supply networks of Arctic facilities. Their advantages in terms of specific power in comparison with diesel power plants and storage devices are shown, but high LNG consumption and environmental indicators limit their use in the Arctic, taking into account the difficult logistics.

Comparison of the energy efficiency of traditional sources and hydrogen storage shows significant advantages of the latter, and if the efficiency of traditional sources increases with their power, the efficiency of storage devices does not change in the entire range of capacities. This circumstance makes the use of hydrogen sources and accumulators in the field of small capacities typical for Arctic consumers uncontested, especially taking into account the possibilities for safe and waste-free technology for processing industrial and life waste.

The paper carries out the analysis of the experimental results on the metals property changes under vacancy-cluster structure effects. We have considered two technological approaches of such structures obtaining. The first one is a nanopowders compaction under high (up to 5 GPa) hydrostatic compression, on example of a Ni nanopowder (70 nm). The second one is the Al and Pb crystallization under the high-intensity plastic deformation [ε′ = (10²–10⁴) sec^–1] (НIPD) conditions on the  solid and liquid  boundary in the centrifugal casting machine with rotary speed up to 2000 rpm. Using the method of atomic force microscopy, vacancy cluster tubes (VCT) with average diameters of 39 nm for Al and 25 nm for Pb have been detected in the crystallized volume of Al and Pb metals. The paper discusses the physical model of a new substructure formation within the metals in the form of vacancy cluster tubes obtained in the process of HIPD during the process of mass crystallization of Al and Pb and the changes in the mechanical, magnetic, and superconducting properties of the above metals, which followed this process. During Al and Pb crystallization under  HIPD range about [ε′ = (10²–10⁴) sec^–1] with specially selected modes of metals crystallization in high-speed centrifugal casting machine, the special conditions are being created to achieve the dimensional effect of dynamic (shifting) recrystallization. Shifting deformation during centrifugal crystallization caused primarily by a large incline of the temperature field from the periphery (relative to the cold wall of the rotor) to the molten central part of the rotor. The difference in the angular velocities of the already frozen part of the metal (adjacent to the outer surface of the rotor wall) and the central part where the metal still remains in the molten state leads to a high-intensity deformation [ε′ = (10²–10⁴) sec^–1] of the crystallized metal melt solidified phase. Since the grain sizes at the crystallized phase initially comprise around tens of nanometers (approximately crystal nucleation size), it becomes possible to achieve the dimensional effect of the dynamic re-crystallization of a “nanocrystalline” solidified metal at high shift of strain velocities. The “non-equilibrium vacancies” formed this way condense into vacancy clusters, which are formed in the centrifugal force field in the form of vacancy-shaped cluster tubes stretched out to the center of rotation of the rotor. The process proceeds under conditions far from the equilibrium in comparison with the usual crystallization of the metal from the melt. Such processes can lead to the formation of highly ordered non-equilibrium states characteristic of non-equilibrium open systems.

The problem of energy efficiency and energy saving is one of the central for the development of modern civilization. In the Russian Federation and all over the world, scientists develop technologies for transition to environmentally friendly and resource-saving energy, search for new sources and ways of transporting and storing energy that will eventually reduce the use of electricity and reduce economic burden on the consumer. Low economic competitiveness and efficiency in comparison with traditional heat sources is the main problem of heat storage systems application in Russia. This problem can be solved by means of new short-term and long-term composite heat storage materials with different operating temperatures, heat transfer time, different heat storage density, etc., depending on the climatic conditions of the Russia regions. Despite a significant number of studies on the characteristics of heat-accumulating materials and attempts to systematize them, there are still no quantitatively reliable data, at the same time recommendations for selection are the basis for the development of optimal heat storage materials for specific applications. Thus the effective heat accumulators for storage of thermal energy for heating and hot water supply of buildings in difficult climatic conditions have not been created. The paper considers the basic principles of heat accumulation, the main types and properties of heat-accumulating materials, and also the criteria for their use in thermal energy storage systems for heating and hot water supply. We have preliminary carried out the selection of hydrated salts as potential materials for heating systems. On the basis of the factor analysis of the quantitative information systematized from available literary sources, we have carried out the data processing and proposed the scheme of the choice of the heat-accumulating materials for heating systems in difficult climatic conditions of Russia.