Citation: Al-Quraan, A.; Al-Mahmodi, M.; Alzaareer, K.; El-Bayeh, C.; Eicker, U. Minimizing the Utilized Area of PV Systems by Generating the Optimal Inter-Row Spacing Factor. Sustainability 2022, 14, 6077. https://doi.org/10.3390/ su14106077 Academic Editors: Francesco Calise, Maria Vicidomini and Francesco Liberato Cappiello Received: 27 February 2022 Accepted: 11 May 2022 Published: 17 May 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). sustainability Article Minimizing the Utilized Area of PV Systems by Generating the Optimal Inter-Row Spacing Factor Ayman Al-Quraan 1, * , Mohammed Al-Mahmodi 2 , Khaled Alzaareer 3 , Claude El-Bayeh 4 and Ursula Eicker 4 1 Electrical Power Engineering Department, Hijjawi Faculty for Engineering Technology, Yarmouk University, Irbid 21163, Jordan 2 Mechanical Engineering Department, Renewable Energy, The University of Jordan, Amman 11942, Jordan; mhm8210520@ju.edu.jo 3 Department of Electrical Engineering, Faculty of engineering, Philadelphia University, Amman 19392, Jordan; kalzaareer@philadelphia.edu 4 Canada Excellent Research Chair Team, Concordia University, Montreal, QC H3H 2L9, Canada; c.bayeh@hotmail.com (C.E.-B.); ursula.eicker@concordia.ca (U.E.) * Correspondence: aymanqran@yu.edu.jo Abstract: In mounted photovoltaic (PV) facilities, energy output losses due to inter-row shading are unavoidable. In order to limit the shadow cast by one module row on another, sufficient inter- row space must be planned. However, it is not uncommon to see PV plants with such close row spacing that energy losses occur owing to row-to-row shading effects. Low module prices and high ground costs lead to such configurations, so the maximum energy output per available surface area is prioritized over optimum energy production per peak power. For any applications where the plant power output needs to be calculated, an exact analysis of the influence of inter-row shading on power generation is required. In this paper, an effective methodology is proposed and discussed in detail, ultimately, to enable PV system designers to identify the optimal inter-row spacing between arrays by generating a multiplier factor. The spacing multiplier factor is mathematically formulated and is generated to be a general formula for any geographical location including flat and non-flat terrains. The developed model is implemented using two case studies with two different terrains, to provide a wider context. The first one is in the Kingdome of Saudi Arabia (KSA) provinces, giving a flat terrain case study; the inter-row spacing multiplier factor is estimated for the direct use of a systems designer. The second one is the water pump for agricultural watering using renewable energy sources, giving a non-flat terrain case study in Dhamar, Al-Hada, Yemen. In this case study, the optimal inter-row spacing factor is estimated for limited-area applications. Therefore, the effective area using the proposed formula is minimized so that the shading of PV arrays on each other is avoided, with a simple design using the spacing factor methodology. Keywords: photovoltaic system; inter-row spacing; tilt angle; effective area; sun path; sun angles 1. Introduction The penetration level of small-scale renewable energy resources, particularly photo- voltaic (PV) systems, has rapidly evolved over recent years. Their low installation and operational costs make these resources competitive in the energy market in those countries that have high solar radiation, such as those located in the Middle East and South Africa (MENA). Several studies have been conducted to investigate the possibilities of maximizing the yield of energy production from renewable power generation, taking the MENA region as a case study, using intensive surveys and theories of theoretical and practical optimiza- tion [1–3]. With more focus on PV systems, roof-top solar energy projects are incentivized due to the simplicity of grid integration and the possibility of trade and exchange within the grid via certain policies [4]. Furthermore, prompt implementation with scalable ca- pacity and a low maintenance cost encouraged communities, households, and companies Sustainability 2022, 14, 6077. https://doi.org/10.3390/su14106077 https://www.mdpi.com/journal/sustainability