POWER LOSS FACTOR OF PV MODULES DUE TO MUTUAL SHADING AND OPTIMIZATION OF TILT ANGLES AND DISTANCE BETWEEN ROWS OF MODULES

• Дата: 2019
• Автори та афіліації: D. Diomin — 1National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute», 03056, 37 Peremohy Av., Kyiv, Ukraine. 2Institute of Renewable Energy of the National Academy of Sciences of Ukraine, 02094, 20А Hnata Khotkevycha St., Kyiv, Ukraine.; A. Gaevskaya — NTUU «Ihor Sikorsky Kyiv Polytechnic Institute» 03056, 37, av. Peremogy, Kiev, Ukraine; O. Gaevskii — NTUU "Igor Sykorsky Kyiv Polytechnic Institute", Peremogy pr. 37, Kyiv 03056, Ukraine, tel/fax: [phone], Renewable Energy Institute, NAS of Ukraine, Gnat Khotkevich str. 20-а, Kyiv 02094, Ukraine, tel/fax: : [phone]
• Ключові слова: keywords
• Автори: Diomin, D., Gaevskaya, A., Gaevskii, O.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Institute of Renewable Energy National Academy of Sciences of Ukraine 2019
• Теми: PV plants; mutual shading of module rows; optimization of tilt angle; optimization of distance between module rows; PV power output.
• Онлайн доступ: https://ve.org.ua/index.php/journal/article/view/229
• Назва журналу: Vidnovluvana energetika

A significant factor affecting on the average daily electricity output by photovoltaic (PV) plants  is the mutual shading by adjacent rows of PV modules. To reduce the mutual shading influence on the PV plant output one have to solve the problem of optimization of the inter-row distances and the height of the PV module arrays, i.e. the modules tilt angles. Despite the geometric nature of this problem, its solution is not trivial, since it's necessary to account the changing of the sun’s height, the variations of the total irradiance on tilted surface and of the ratio of the direct and diffuse irradiance components during the daylight hours and during the entire calendar operation period of PV plant. In this paper, in order to describe the degree of influence of partial shading on the output power of PV rows the power attenuation factor due to shading has been introduced.  This factor is determined on the basis of experimental current-voltage characteristics (CVC), which were measured by the device developed in this work for testing of PV modules in field conditions with bottom shading in cases of horizontal and vertical arrangement of modules. The obtained dependences of the PV power attenuation factor on the shading degree are used to calculate the average daily PV energy output maps in the coordinates “row placement density – tilt angle”. As initial data, in addition to the power attenuation factor, are the hourly direct and diffuse insolation on a horizontal surface for each month of the PV plant operation. The developed method makes it possible to find the optimal configurations of the PV rows for two types of optimization problems: (1) ensuring maximum output at a given PV plant power and (2) obtaining maximum PV system output per unit area of the site. The method is applicable for any seasonal period of PV operation and for any region for which the above-mentioned insolation data are available. Ref. 22, fig. 9.