sustainability Article Accessibility and Sustainability of Hybrid Energy Systems for a Cement Factory in Oman Wesam H. Beitelmal 1, * , Paul C. Okonkwo 1, *, Fadhil Al Housni 2 , Wael Alruqi 3 and Omar Alruwaythi 4   Citation: Beitelmal, W.H.; Okonkwo, P.C.; Al Housni, F.; Alruqi, W.; Alruwaythi, O. Accessibility and Sustainability of Hybrid Energy Systems for a Cement Factory in Oman. Sustainability 2021, 13, 93. https://dx.doi.org/10.3390/su13010093 Received: 12 November 2020 Accepted: 22 December 2020 Published: 24 December 2020 Publisher’s Note: MDPI stays neu- tral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2020 by the authors. Li- censee 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/). 1 Civil & Environmental Engineering Department, College of Engineering, Dhofar University, Salalah 211, Oman 2 Mechanical & Mechatronics Engineering Department, College of Engineering, Dhofar University, Salalah 211, Oman; falhousni@du.edu.om 3 Civil Engineering Department, College of Engineering, Jouf University, Sakaka 72388, Saudi Arabia; waelalruqi@ju.edu.sa 4 Civil Engineering Department, College of Engineering, Taibah University, Medina 42353, Saudi Arabia; oruwaythi@taibahu.edu.sa * Correspondence: wbeitelmal@du.edu.om (W.H.B.); pokonkwo@du.edu.om (P.C.O.) Abstract: Diesel generators are being used as a source of electricity in different parts of the world. Because of the significant expense in diesels cost and the requirement for a greener domain, such elec- tric generating systems appear not to be efficient and environmentally friendly and should be tended to. This paper explores the attainability of utilizing a sustainable power source based on a cross- breed electric system in the cement factory in Salalah, Oman. The HOMER software that breaks down the system setup was utilized to examine the application and functional limitations of each hybridized plan. The result showed that a renewable-energy (RE)-based system has a lower cost of energy (COE) and net present cost (NPC) compared to diesel generator-based hybrid electric and standalone systems. Although the two pure renewable hybrid energy systems considered in this study displayed evidence of no emissions, lower NPC and COE values are observed in the photo- voltaic/battery (PV/B) hybrid energy system compared with photovoltaic/wind turbine/battery (PV/WT/B). The PV/WT/B and PV/B systems have higher electricity production and low NPC and COE values. Moreover, the PV/B has the highest return on investment (ROI) and internal rate of return (IRR), making the system the most economically viable and adjudged to be a better candidate for rural community electrification demands. Keywords: hybrid electrical system; sustainability; renewable energy; HOMER software; commu- nity; electricity 1. Introduction The demand for fossil fuel is increasing and likely to be limited in supply in the com- ing years due to government policies, environmental pollution, production, and logistical challenges. Although Oman is a petroleum and natural gas exporting nation with estimated reserves of 4.7 billion barrels of oil and 25 trillion cu ft of natural gas, the reserve to pro- duction ratios (R/P) are only 15 and 18 years, respectively [1]. As such, an examination of renewable/hybrid energy is warranted. Recently, Oman has adopted the Vision 20–40 plan, including the ninth five-year plan covering the period 2016–2024 [2]. The arrangement is pointed toward decreasing the nation’s dependence on oil and gas creation by broadening the economy in the industrial and financial areas. Another agenda of the Oman Vision 20–40 plan in diversifying the economy is for Oman to invest in renewable energy [3]. Furthermore, due to the demand for a greener environment in the 21st century, there has been a growing demand for renewable energy sources both globally and within Oman [3–8]. The availability of renewable energy can not only provide a continuous power supply, but also supply an energy demand balance in the electrical power system [9]. The energy Sustainability 2021, 13, 93. https://dx.doi.org/10.3390/su13010093 https://www.mdpi.com/journal/sustainability