Information-measuring technologies (IMT) are an important instrument for solving problems of energy informatics. They allow to form primary information based on the interaction of energy facilities with IMT sensors that form information signals. In many practical applications, the constructive model of information signals is the model of narrowband signals. The article summarizes the features of the discrete Hilbert transform and its application to obtain the primary characteristics of information signals – bypass and phase as functions of time. The main advantages of using the discrete Hilbert transform in signal processing for energy informatics are considered, including the consistency of obtaining frequency and time characteristics, high information content, the ability to analyze the dynamics of changes in signal characteristics, the possibility of obtaining samples of characteristics of information signals of significant volumes, etc. It is proposed to use a phase characteristic to select the time interval that limits the signal sample and sets it to a multiple of the signal period, and the sampling rate of information signals to reduce the errors in estimating their spectrum. The possibility of obtaining on their basis secondary deterministic (voltage level, voltage deviations from the nominal level, attenuation coefficient, signal period, signal phase shift, oscillation frequency, etc.) and statistical (sample characteristic, sample variance, sample median, sample circular variance, sample circular median, sample circular kurtosis, etc.) of signal information characteristics, which allows more complete to use their information resource. These characteristics can be used both for assessing power quality characteristics and for monitoring and diagnosing of energy facilities. Keywords: energy informatics, information signals, signal processing, discrete Hilbert transform, amplitude signal characteristics, phase signal characteristics

A mathematical model is proposed for optimizing the modes of using the generating capacities of the national energy system in the conditions of competition and interstate agreements and requirements, which has the advantages of adequately modeling the modes of using hydroelectric units and power units, for the mode of synchronous operation of the power systems of Ukraine and Poland for characteristic days, using the example of actual values of installed capacity and load schedules. The model belongs to the class of optimization problems with the criterion of minimizing the costs of production and import of electricity. It is implemented in the SolverStudio optimization package in the MathProg algebraic modeling language using the COIN-OR PuLP modeling language. The use of the model made it possible to explore the possibilities of optimized dispatching of generating capacities, as well as reserve capacities of large-capacity storages, the limits of permissible values for the parameters of generating and storage capacities, and cross-border flows, in which stable balanced operation of the unified energy system is possible. Model calculations of the parameters that provide optimized coverage of load curves for a typical day are performed using the example of actual values of installed capacity and load curves in 2018. The specific features accounting of the operation of generating, reserve and storage capacities of power systems in the model made it possible to determine and explore the possibilities of optimized dispatching of the components, the boundaries of permissible values of the parameters of generating and storage capacities, under which stable balanced operation of energy systems in synchronous operation modes is possible. The simulation results can be applied in the tasks of forming predictive balances for covering daily schedules of electrical loads to study the prospects for short- and long-term development of storage and generating capacities, the optimal achievable volumes of cross-border electricity flows between the energy systems of Ukraine and neighboring countries included in ENTSO-E, which is relevant in conditions of connection to these power systems. Keywords: load schedules, modes of synchronous operation of power systems of Ukraine and Poland

There is a deficit in united energy system of Ukraine of installed capacity of flexible generation units which are able to quickly reach the operating mode, change the power generation levels in a wide range. To model additional measures increasing the flexibility of the power system, it is necessary to know the technical and economic indicators of thermal power technologies and its specific operating modes. The purpose of the article is to determine: efficiency factors depending on the power unit load; start-up costs depending on downtime duration and different fuel prices; the influence of maneuvering modes on lifetime resource indicators; as well as comparison of indicators for various technologies of thermal energy. The following thermal power technologies: natural gas, hard or bituminous coal fired steam turbine supercritical pressure, steam-gas, gas turbine open cycle and gas piston engines. The calculation formulas allowing estimate the influence of the power plant operation mode on the efficiency is obtained. The results of calculation of the start-up specific costs depending from the type of the unit and the idle time is presented. The different values of thermal power unit start-up cost are presented depending on idle time. As an example, the balancing of 660 MW electric power with different equipment composition are considered. The analysis of the results shows that the highest start-up cost is for coal-fired steam turbine plants, and the composition of the equipment with the lowest start-up cost varies depending on the downtime: up to 2 hours, 2 – 5 hours, more than 5 hours. Formulas for recalculating the cost of starting at different fuel prices are obtained. The influence of maneuvering modes on the lifetime resource indicators of thermal power plants is also presented. The conventional thermal power generators of the united energy system of Ukraine have actually overcome their physical capabilities to ensure effective load following, therefore, it is necessary to introduce new highly flexible capacities, and the proposed formulas and results could be helpful to determine the volumes and characteristics of new thermal power plants needed to implement into power system. Keywords: thermal power, maneuverable mode, efficiency, downtime, start-up cost, service life

One of the important tasks in the short-term forecasting of the work of the united energy system (UES) of Ukraine is to ensure grid balance reliability, one of the key elements of which is the reliability of fuel supply. Today in Ukraine to solve this task the forecast of the electricity balance (FBE) is developed, within which balance of fuel for TPPs is formed, but the methodology of its development has certain shortcomings which are analyzed in article. The article proposes an approach to improving the development of FBE by the introduction into practice a specialized optimization mathematical model to calculate the required total change in fuel stocks at TPP. The developed mathematical model takes into account the modes of TPPs operation, requirements for limiting emissions to the air according to National Emission Reduction Plan, restrictions on the possibility of fuel supply. The article provides a detailed description of the developed mathematical model, and also presents the results of test calculations and comparison with the official data of the Ministry of Energy of Ukraine on the need for total fuel reserves for TPPs. The results show: 1. It is expedient that the methodology of FBE formation should be improved taking into account a number of factors, in particular, to take into account the restrictions on air pollutant emissions volumes while determining electricity generation capacity at different groups of power units, the opportunities for general fuel supply for all TPPs, more reliable forecast of electricity production at individual TPPs provided by FBE than according to retrospective data. Improving the methodology of FBE formation can be based on the developed mathematical model of optimal monthly national electricity balances calculation which operates with separate groups of TPP power units with similar technical and economic parameters. 2. Comparisons of the obtained results with the Ministry of Energy of Ukraine’s actual forecasted data about accumulation of fuel stock indicated significant difference. The latest forecast is unrealistic in terms of its feasibility - the need to ensure a sharp increase in fuel stocks in the short term against the background of growing electricity production at TPPs, while the previous forecast had an underestimation of the need for fuel reserves. 3. The results of calculations for FBE 2021 showed that the accumulation of fuel reserves should be carried out in April - June. 4. The introduction of the proposed mathematical model will ensure taking into account the number of important factors in the context of providing TPPs with fuel, which are not taken into account by the existing Procedure for its development. This will increase the reliability of electricity supply to consumers by minimizing the risks of lack of necessary fuel stocks at TPPs. Keywords: electric power system, thermal power plants, fuel balance, forecast electricity balance, fuel reserves

Ukraine is obligated to adopt Nationally Determined Contribution to the Paris Agreement (NDC2) in 2021 for a period up to 2030 as a percent of 1990, requiring correct projection of green-houses gases (GHG) emissions first of all in key categories, one of that is heat and electricity production by thermal power plants (TPP) and combined heat and electricity production (CHP) which are burning organic fuel. The Ministry of environment protection and natural resources of Ukraine (MEP) proposed GHG reduction of 65% compared to 1990 which is about 3.2% lower compared to 2018, and there is a very ambitious goal taking into account desired rapid Ukrainian economic growth. To assess the reliability of this proposal the appropriate modeling GHG emission reduction from TPP and CHP was made and presented in the article. The modelling was made taking into account methodological approaches of TIMES-Ukraine modeling system, which is the basic tool for assessment of GHG reduction potential in Ukraine for MEP, and also alternative one used in BACS-RVE modeling tool, which was used for calculations for "Generation Adequacy report" which was developed by Ukrainian transmission system operator "Ukrenergo". The analysis of the modeling results showed that neglecting in the methodology used in TIMES-Ukraine the operation modes of generation and required levels of power grid balance reliability indicators does not allow fully adequately project power system development. The modeling results using BACS-RVE modeling tool showed that the reference case scenario of generation development (according to the TIMES-Ukraine) could be feasible under the condition that GHG emission tax should not be less than 100 EUR per tonne of CO2eqv, and potentially will cause the increase of electricity price. Another important result obtained using BACS-RVE is that GHG emission level for 2030 is higher compared to the reference case scenario, hence additional modeling and discussion of results are required to ensure well-grounded GHG emission projection which will allow reviewing NDC obligation for the power sector of Ukraine. Keywords: power system, greenhouse gases, modeling, load profiles, grid balance reliability

Науковий збірник «Проблеми загальної енергетики», засновником якого є Інститут загальної енергетики Національної академії наук України, включено до переліку наукових фахових видань України, в яких можуть публікуватися результати дисертаційних робіт на здобуття наукових ступенів доктора і кандидата технічних наук

The purpose of this paper is to explore the influence of the new Ukrainian and European regulatory framework for 2019-2020 concerning the decarburization of economy of the functioning of Ukrainian gas industry. The paper provides an overview of the Ukrainian regulatory framework of 2019–2020 on the implementation of the system of monitoring, reporting, and verification of greenhouse gas emissions in our country. We also provide an overview of new European documents on the decarbonisation of economy, in particular, the European Green Deal, the EU Strategy for Reducing Methane Emissions, and the Hydrogen Strategy for Climate-Neutral Europe. We showed that these EU documents will exert a significant influence on the functioning of both the energy sector of our country as a whole and its part – gas industry. The paper shows that, under the existing plans of the development of energy sector in European countries in order to reach the state where there are no net emissions of greenhouse gases by 2050 and under conditions of fierce competition for sources and routes of gas supply to the European market, the most pressing problem confronting the gas transportation system of Ukraine is to optimize its structure with simultaneous replacement of outdated compressor equipment by modern one with lower carbon dioxide emissions, which will require a significant amount of investment. Under such conditions, it is necessary to study carefully the feasibility of introducing activities for the main transportation of gas under the action of Greenhouse Gas Trading System. We also showed that the reduction of methane emissions along the natural gas chain supply in accordance with the EU Strategy for the reduction of methane emissions is extremely important for Ukraine. In addition to the implementation of measures for reducing these emissions, it is necessary to attract attention to the development of national methods for estimating methane emissions and the use of national coefficients in the formation of the National Greenhouse gas emissions inventory for estimating volatile emissions from natural gas activities. Keywords: monitoring, reporting and verification of greenhouse gas emissions, Greenhouse Gas Trading System, decarbonisation, European Green Deal, gas transportation system

The peculiarity of the operation of solar photovoltaic power plants is the dependence of the generation power on weather conditions, which leads to the maximum production of electrical energy at noon hours of the day. Due to a decrease in electricity consumption, insufficient unloading capacity of pumped storage power plants in the integrated energy system of Ukraine and the specifics of electricity production at solar photovoltaic power plants, dispatching restrictions on the level of generation power are already taking place. To transfer volumes of electrical energy in the world, electrical energy storage systems are used, which operate based on lithium-ion storage batteries. Such systems have a number of advantages over other battery energy systems, which allows their implementation in almost any power generation facility. With the help of energy storage systems, it is possible to make a profit through the purchase of electric energy during a period of low prices and its release during a period of high prices, allowing consumers to save money on its payment. In this paper, we simulate the use of a battery energy storage system for storing electrical energy to transfer excess electrical energy from a solar photovoltaic power plant. To conduct a study and identify excess capacity of a solar photovoltaic power plant, the daily schedule of electrical load is equalized to the capacity of a separate power plant Because of the study, the optimal time for charging and discharging the battery was determined, from which it can be seen that the need to transfer excess electricity to a solar photovoltaic power plant occurs at lunchtime, and their discharge at the peak is the graph of the electrical load of the power system. The aggregate operation of a solar power plant with a total installed capacity of photovoltaic power at the level of 10 MW (DC) and a battery energy storage system for accumulating electric energy with a capacity of 3.75 MWh was simulated. For the study day, the required capacity of a battery system for accumulating electric energy at the level of 1.58 MW was determined. Using the methodology of the levelized cost of electricity and storage, a technical and economic assessment of the transfer of excess capacity of a solar photovoltaic power plant using a battery system for storing electrical energy was carried out. When calculating the cost of storage, the cost of the transferred electrical energy from the solar power plant was taken into account. From the results of technical and economic calculations, it can be seen that, in terms of the cost of equipment, as of 2020, the cost of supplying excess electrical energy from the battery energy storage system is growing when compared with the supply from a solar photovoltaic power plant. Taking into account some forecast assumptions, the cost of electricity supply from the battery energy storage system was calculated for the mode of transferring excess capacity of a solar photovoltaic power plant for 2025 and 2030 years. Keywords: modeling, power system, load demand curve, solar photovoltaic power plant, electric energy storage system, cost

To ensure the balance reliability of regimes of UES functioning, it was necessary to apply restrictions on generation from renewable energy sources (RES). In this regard, a number of amendments was made in 2020 to the Law of Ukraine "On the Electricity Market" dated April 13, 2017 No. 2019-VIII, which provide for reduction of the rates of the "green" tariff for renewable energy projects. CJSC NEC "Ukrenergo" predicts limitation of electricity production from renewable sources against the background of their growing capacity and falling consumption – up to 1 billion kW∙h. The total volume of electricity production from renewable energy sources in 2019 was about 4.5 billion kW∙h. One of the most efficient ways to use excessive electricity is producing hydrogen. Hydrogen has been successfully used as a raw material for many years. The total estimated value of the hydrogen feedstock market is $ 115 billion, and it is expected only to grow, reaching $ 155 billion by 2022. Hydrogen is widely used at present in various industries and sectors. It should be noted separately that the use of hydrogen instead of natural gas does not lead to increasing greenhouse gas emissions and favors the decarbonization of economy. In addition, the by-product of electrolysis is purified oxygen, which is currently relevant. The cost of hydrogen generated with the use of renewable electricity is typically $ 2.5–6.6 / kg of hydrogen. The most well-known technological options for producing hydrogen from RES are water electrolysis and steam reforming of biomethane / biogas with or without carbon capture and use / storage. The purpose of this paper was to estimate the weighted average cost of hydrogen in Ukraine at the expense of RES electricity, in particular, produced by a wind power plant with using water electrolysis. We developed an algorithm for calculating the weighted average cost of hydrogen production using wind power plants for the conditions of Ukraine, taking into account the determination of installed capacities of the battery, electrolyzer, and distiller. According to the calculation results, the weighted average cost of hydrogen production was about US $ 5.1 / kg of hydrogen. Keywords: hydrogen production, renewable energy sources, wind farm, weighted average cost. mathematical model, storage, electrolyzer