Realistic assessment of wind farms natural instability is important for the proper organization of the grid. Correct modeling of joint work of energy system and wind farms requires consideration of the local wind behavior. Comparison of actual data for selected regions allows us to choose the most adequate mathematical model.

This article gives an analysis of the use of different methods of solving the problem of calculating the magnetic field in a variety of devices, widely spread in the area renewable energy and related industries, a feature of which is the use of extended magnetic systems. It is shown that the computational model of such systems in many cases reduced to an infinite plane magnetic layer in the specified sources, but the decision of this task by known methods have certain limitations. This article is designed to obtain for her a versatile method of compact solution in closed form, suitable for engineering calculations.

Survey, parametric, oil and gas wells, which are derived from the operation may be used for extraction of earth warmth. The depth of these wells in Ukraine reaches 4000-5000 m and more. Geothermal gradient in the territory of the Dnieper-Donets depression on averages 2.7 °С/100 m, and in the area of Prykarpathia and Transcarpathia - 3,6-4,0 °С/100 m. Defined the following problem of unsteady heat transfer counter flow of heat carrieri in geothermal well. Calculated the specific heat flow from the mountain massif in the well using the solutions of the linear source (drain) in an endless mountain range and compared with available experimental data. Specific heat flow from the mountain massif to the coolant in the well varies 3 times at the end of 560 hours at a temperature drop 10 °С and further change in temperature over time is linear. The maximum thermal performance of the well depth of 5000 m at a geothermal gradient of 2.7 is 1.3 MW at the end of 40·10³ hours it drops to 0.65 MW.

Presents guidelines for the development of a number of technological schemes of gas-powered plants for sub-standard small undeveloped gas fields and gas fields of geothermal waters.

Analyzed the construction project risks of small hydropower plants in view of regulations and mechanisms to encourage the development of small hydropower in Ukraine and Russia. Is considered the method risk management of accidents hydraulic structures during construction and operation of small hydropower plant.

In this article, using the finite element method analyzed the distribution of the temperature field of the photothermal composite module under various conditions of the heat sink.

In the article provides the synergetic analyses of the possible reasons of the formation of spatially heterogeneous pattern at solar drying moisture contain materials. Considered in process of complication variants of models temperature condition moisture contain mediums, in particular, the temperature condition model in a simple nonlinear heat variant and heat conductivity model with taking into account the heat transfer by convection the filtration through moisture contain mediums steam.

We justify the conditions of effective use of platforms for photovoltaic power plants and rational modes of operation the main equipment of stations.

In the current work the method of power distribution evaluation was developed, which takes into account not only the path of solar beams into inner area of concentrator, but beams intensity too. The mirror of the concentrator assumes as a set of small flat segments, and the issue is solving in quasi-classical Kirchhoff approximation. Current method can be used for radiation intensity maps creating for free shape concentrators and for optimization of the mirror-receiver system.

The article analyzes the general properties of entropy in a nonequilibrium steady state stability conditions for equilibrium and nonequilibrium states, issues of negative entropy production.

For development of high intensive burners it is necessary explore possibilities to intensify all stages of solid fuel combustion. The features of thermal decomposition (thermolysis) of wood pellets with volatile substances release in furnace of boiler or heat generator were regarded. Calculation of volatile release duration based on available dependencies, derived using slow heating of wood particles in an inert atmosphere, gives results that significantly exceed observed at combustion. Procedure of experimental investigation to determine duration of volatile release period at thermolysis of wood pellets, having 6 mm in diameter, in an oxidizing atmosphere in the muffle furnace is described. The influence of muffle temperature, humidity and length of pellets were investigated. Experimentally determined period of volatile release in oxidizing atmosphere is from 2 up to 4 times less than that estimated for inert atmosphere. Dependence of volatile release duration from temperature is exponential in nature, and that from the pellets length is close to hyperbolic tangent. Period of volatile release increases with the pellets length increasing up to 30 mm and at further increasing of pellet length remains constant. The period of volatile release for wood pellets with moisture content W = 10.1% is 20% more compared with that for dry pellets.

The combined usage of poultry manure and agricultural waste cellulose to produce biogas in the fermentation process are shown. The concentration of cellulose-containing raw material affects on the yield of biogas and its qualitative consists. The maximum yield of biogas and energy carrier concentration will occur with substrate components at a ratio of manure/corn waste -3:2. With such component ratio speed of cellulose raw material conversion will rise. The yield of biogas has a sinusoidal structure as a result of acidity changes in substrate.

The article identifies factors that increase the performance, the service life of structures buildings using energy active fencing and alternative sources of energy. Heat engineering and constructive features of energetically fence allow not only to reduce the risk of thermal deformation, but also to avoid the accumulation of moisture in the load-bearing structure construction. The application of energy active fencing prevents violation of the conditions exploitation of constructions due to stabilization of quality of heating. The result of energy active fencing and use of alternative sources of energy is a significant increase of the lifetime of structures. Implementation of integrated systems energy supply with energy active fences and using alternative sources of energy is a significant reduction in the consumption of organic fuels (gas, coal, etc.). Rational use of solar energy reduces the cost of heating buildings.