The high standards for the power supply leads to the fact that the task of saving energy resources becomes the state priority. In order to increase the efficiency and sustainability of modern cities and various industrial centers, people use of renewable energy sources, which have the required capabilities, in particular solar power engineering. The researches of various types of solar units have to solve the task of maximum solar energy conversion efficiency in the necessary form. The authors of this paper develop the scheme of complex energy delivery to isolated objects from a solar collector. The peculiarity is the use of heating pumps which increase year-round efficiency of combine solar collector usage.

This paper describes the ice protection system using the ultrasonic radiation for automatic removal of ice from the wind power plant blade surface. Operating components inside the blade are arranged for maximum reduction of energy consumption and increase of the system efficiency. The authors proposed the usage of devices on the base of renewable energy sources such as solar panels, for electric power supply of operating components ice protection  system. The paper also gives the examples of other ice protection alternatives for wind turbine blades in low temperature conditions, including publications of colleagues in this area. The authors compared similar systems and discussed the advantages of the proposed ultrasonic radiation based system; and presented a method for the system component calculation and partially the functional modules showing the simplicity of the discussed system both in montage and practical usage.

The paper analyzes the influence mechanisms of a number of design parameters, in particular wind rotor (WR) diameter, the number of blades and their air dynamic characteristics, etc. on economic and power curves of wind units (WU) of small, medium and high output. It is considered the impact of the average annual wind speed on cost price of WPU production and the cost of produced power. The paper researches the influence of the application of a packet type multiplier on power and economic curves of WPU and the influence mechanisms of a number of aerodynamic coefficients of the blades, in particular of the coefficients of lift, drag, ram pressure, lateral force and braking on numerical values of WR output coefficient and high-speed running factor. The authors also consider the nature of the changes of these parameters depending on different angles of the blades attack, located between the direction of the wind flow and the blade chord; the tangent of the angle defined by the ratio of the lift coefficient by a factor of ram pressure and characterizing the quality and profile of the blade; as well as on the scope of the blades determined from the ratio of the length of the blades to the length of its chords.

The article deals with the monoblocked trigeneration experimental plant for power supply of autonomic objects. The power plant consists of power unit in the form of a diesel generator, geothermal heat pumps as sources of heat and cold supply, heat recovery boiler of exhaust heat. The heat pump compressors are driven from the shaft of the diesel engine through a V-belt transmission. On the proposed installation, the energy supply of autonomic consumers can be organized in monogeneric, simple and complex cogeneration and trigeneration modes. The article also demonstrates the results of experimental study of power plant characteristics, confirming its performance in complex cogeneration mode.  The values of the energy conversion factor, obtained during testing of heat pumps in the composition of trigeneration plants, show the energy efficiency of their work for the heating mode. The author experimentally identifies the components of the energy balance, and then the composition of the exhaust gases at different levels of the load.

The paper considers methane fermentation technology of bio waste fermentation with heat recovery of waste effluent heat. In order to improve the energy efficiency of a biogas plant the authors propose technological scheme of waste heat recovery effluent, which allows using biogas plants in regions with low average annual temperature. Based on the technique of thermal and thermodynamic analysis it is comparatively assessed the energy efficiency of two biogas plants:  the traditional and the recovery of waste heat of the effluent. The paper presents a detailed calculation of digester thermal and energetic efficiency, because it is a key unit of the scheme of the apparatus. The use of heat pump in biogas plant heating system will increase the thermal efficiency of the scheme from 39% to 46%, and the exergy efficiency from 6% to 31%.

The article analyses the qualitative and quantitative content of impurities in the Freon 113 and illustrates the sorption purification from impurities of different chemical nature using sorption methods. This approach is characterized by high indicators from the standpoint of resource saving and ecology. The authors of this article use active carbon and zeolites with different structures as adsorbents. Studies have shown that the impurities content reducing in the target product to the standards of the relevant commodity one is possible, and that the greatest effect of integrated treatment of the Freon from impurities, when using microporous sorbent material, is achieved by the use of zeolite NaX, which has the largest size of the entrances to the pores of the commercially available zeolites.

The paper carries out the research on the bulk ceramic high-temperature superconductors in resistive state and analyses two physical situations: dissipative motion of magnetic flux vortices throughout the whole sample, and localised in a thin near-surface layer. Hysteresis character of granular superconductor resistance in resistive state in case of change of external magnetic field has been detected. It is shown that a small alternating magnetic field ambiguously influences the resistance of HTSC in resistive state dependıng on the frequency due to the redistribution of magnetic flux vortices from weak pinning centres (from intergranular medium) to stronger centres (to granules).