Keywords: renewable energy sources, solar power station, wind power plant, energy balance, random process, optimization.


The purpose of the paper is to determine the optimal ratio of different sources of renewable energy in hybrid power systems, based on the estimation of the random component of power generation and electricity consumption. For this purpose short-term power fluctuations caused by natural changes in solar and wind energy in the time frame of less than an hour are considered. Such changes affect the performance of frequency and voltage regulation, as well as the stability of power supply systems. The subject of the study is the proportion of wind and solar generation with its overall level of electricity consumption and the point of optimization – the variability of the total generated power. The key feature of the work is the synchronous alignment of the levels of energy generation and consumption by different local consumers. Methods of research are a mathematical model of a combination of random processes and the direct use of experimental statistical data. The chosen method of optimization is the construction of the response surface, which provides the visualization of the results with satisfactory accuracy. If necessary, the result is specified by the method of dichotomy. The outputs of the study are compared with different weather factors, so the data of the different seasons were examines. The obtained dependencies also allow to estimate the influence of energy efficiency of wind and solar power engineering as a technological factor. Among the important results is when drawing up the schedules of the power system it is possible to estimate the influence of the prediction accuracy of generation and consumption capacities on the energy balance: the presence of a daily forecast allows to increase the power of RES in 1.5 times, while maintaining the level of variability. The existence of optimal ratios of the WPP and PV power with the minimum general variability of the energy balance is established. In Ukraine it is about one third of the rated power of the wind power and two thirds of the PV, but the results are significantly dependent on the season. The optimality criteria are considered, taking into account the random nature of the investigated processes, which gives the possibility of probabilistic estimation of the results. References 13, fig. 6.

Author Biographies

M. Kuznietsov, Institute of renewable energy, NAS of Ukraine, 02094, 20А Hnata Khotkevycha St., Kyiv.

kuznietsov.jpgAuthor information: Deputy Director of the Institute of Renewable Energy at the NASU, Doctor of technical sciences.
Education: Taras Shevchenko Kyiv State University, Faculty of Mechanics and Mathematics.
Research area: mathematics, renewable energy.
Publications: over 60, including 3 monographs.

O. Lysenko, Tavria State Agrotechnological University, 72310, 18 B.Khmelnitskoho Avenue, Melitopol

lysenko.jpgAuthor information: Associate Professor, Department of Energy and Automation Tavria State Agrotechnological University, Associate Professor, Candidate of Technical Sciences.
Education: Tavria State Agrotechnical Academy, Energy.
Research area: power supply, renewable energy.
Publications: over 40, including 4 patents.

O. Melnyk, National Technical University of Ukraine “Igor Sikorsky Kiev Polytechnic Institute", 03056, 37 Peremohy Av., Kyiv

melnyk1.jpgAuthor information: graduate student, research engineer.
Education: National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Faculty of Electric Power Engineering and Automatics.
Main research interests: electric power engineering, renewable energy.
Publications: 6.


1. Lezhniuk, P., Komar, V. i Sobchuk, D. Otsiniuvannia vplyvu dzherel vidnovliuvanoi enerhii na zabezpechennia balansovoi nadiinosti v elektrychnii merezhi. [Assessment of the impact of renewable energy sources on the reliability of the electri-cal network]. Visnyk of Vinnytsia Polytechnical Institute. 2013. No. 6 Pp. 45-47. Retrived from index.php/visnyk/article/view/1005. [in Ukrainian].
2. Bernal-Agustín J.L., Dufo-Lopez R. Simulation and optimization of stand-alone hybrid renewable energy systems. Renewable and Sustainable Energy Reviews. 2009. Vol. 13. No. 8. Pp. 2111-2118. doi:10.1016/j.rser.2009.01.010. [in English].
3. Bhandari B. et al. Optimization of hybrid renewable energy power systems: A review. International journal of precision engineering and manufacturing-green technology. 2015. Vol. 2. No. 1. Pp. 99-112. [in English].
4. Wang X., Palazoglu A., El-Farra N. Operational optimization and demand response of hybrid renewable energy systems. Applied Energy. 2015. Vol. 143. Pp. 324-335. doi:10.1016/j.apenergy.2015.01.004 [in English].
5. Siddaiah R., Saini R. A review on planning,configurations, modeling and optimization techniques of hybrid renewable energy systems for off grid applications. Renewable and Sustainable Energy Reviews. 2016. Vol. 58. Pp. 376-396. doi:10.1016/j.rser.2015.12.281 [in English].
6. Bahramara S., Moghaddam M., Haghifam M. Optimal planning of hybrid renewable energy systems using HOMER: A review. Renewable and Sustainable Energy Reviews. 2016. vol. 62. Pp. 609-620. doi:10.1016/j.rser.2016.05.039. [in English].
7. Pavlovskyi V.V., Lukianenko L.M., Goncharenko I.S., Zaharov A.M. Obmezhennya potuzhnosti vidnovlyuvanykh dzherel enerhiyi za umovamy pryyednannya do elektrychnoyi merezhi. [Limitation of res power under the terms of connection to electric network]. Works of the Institute of Electrodynamics of the National Academy of Sciences of Ukraine. 2016. No. 43. Pp.18-23. [in Ukrainian].
8. Kuznietsov M., Uzheyko S. Imovirni aspekty vykorystannya vidnovlyuvanykh dzherel enerhiyi v zoni vidchuttya Chornobylskoyi AES. [Probabilistic aspects of renewable energy using in the Chernobyl zone]. Vidnovluvana Energetika. 2016. No. 3(46). Pp. 6-12. Retrived from[in Ukrainian]
9. Kuznietsov M.P. Vplyv vitrovoi enerhetyky na statychnu stiikist enerhosystemy [Influence of wind energy on the static stability of the grid]. Vidnovliuvana enerhetyka. 2015. No.3. Pp. 5-9 [in Ukrainian].
10. Lysenko, O. Otsinka vypadkovykh vlastyvostei rivniv
spozhyvannia elektroenerhii. [Estimation of random properties of electricity consumptionlevels]. Vidnovluvana Energetika. 2018. No. 1(52). Pp.26-35. Retrieved from [in Ukrainian].
11. Kuznietsov M. Pobudova matematychnoi modeli rezhymu spozhyvannia elektroenerhii. [Construction of a mathematical model of electricity consumption mode]. Vidnovluvana Energetika. 2017. No. 4(51). Pp. 33-42. Retrieved from
[in Ukrainian].
12. Olsson M., Perninge M., Soder L. Modeling real-time balancing power demands in wind power systems using stochastic differential equations. Electric Power Systems Research. 2010. No. 80. Pp. 966-974. [in English].
13. Kuznietsov M.P., Lysenko O.V., Melnyk O.A. Osoblyvosti stokhastychnoi optymizatsii hibrydnykh enerhosystem na bazi VDE. [Features of stochastic optimization for hybrid power systems with the renewable sources]. Vidnovluvana Energetika. 2018. No.2. Pp. 6-15. [in Ukrainian].

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How to Cite
Kuznietsov, M., Lysenko, O., & Melnyk, O. (2019). TO OPTIMAL COMBINATION OF WIND AND SOLAR ELECTRICITY. Vidnovluvana Energetika, (1(56), 10-19.
Complex Problems of Power Systems Based on Renewable Energy Sources