**1. Introduction**

Energy is the most important ingredient in both developing and developed countries that contributes to the overall economic and social development [1–3]. There is a strong relationship between energy sources availability and economic growth and hence social development. Studies revealed that energy demand is rapidly increasing globally. It is expected to increase by about 65% in the developing countries and approximately about 34% on the global scale by 2040 [4]. This is due to several factors, including fast-paced prosperity, economic expansion, and continuous population growth. However, during the last 25 years, the reality and impact of environmental degradation have become visible as a result of a combination of factors such as increased energy demand and industrialization, which both imposed stress on energy production. Nowadays, conventional energy production systems—Namely fossil fuel-based systems—Are considered to be the primary cause of

the increased environmental degradation due to their carbon dioxide (CO2) emissions [5]. According to Timmerberg et al. [6], the estimated rate of CO2 emissions in the Middle East region is 0.396–0.682 kg CO2 kWh<sup>−</sup>1, which means a considerable amount of CO2 is released into the atmosphere. However, as they indicated, if the target for 2030 of the renewable energy share is met, the electricity-production CO2 emissions are expected to drop to 0.341–0.514 kg CO2 kWh−1. Attaining solutions to such environmental problems that we face today, long-term planning and actions become vital for sustainable development [1]. Also, a large portion of the industry's research is heavily focused on advancements that reduce operational [7,8] or mending energy [9,10]. Besides, more importantly, renewable energy sources play a significant role in mitigating environment-related problems as they are environmentally friendly with affordable and competitive costs relative to conventional energy systems [11–13].

Jordan is one of the developing countries in the Middle East, with more than 97% of its energy being imported. This has a significant impact on the country's economy [14]. Moreover, the energy security of the country is threatened by the fluctuations of fossil fuel prices as well as the disruption of fossil fuel supplies, which happened in 2011 [15]. The most affected zones are usually rural areas, where infrastructure is not quite robust, and the electrical service coverage is weak. According to the economic research service of the United States Department of Agriculture [16], the delineation introduced in 2000 defines countryside with 500 people per square miles or less as rural areas. Developing countries' poverty problem is aggravated by inadequate electrification of these remote sites. In Malaysia, for example, around 809 schools do not have a 24-hour electricity supply [17]. Modern energy forms are considered an economic good that can lift up the life of billions worldwide, predominantly in developing countries that lack service availability [18,19]. That said, from an economic standpoint, grid transmission through the impenetrable terrains and dense forests to supply a small village is not viable. Therefore, because of the high distribution cost and accompanying transmission losses, serving rural areas become unfeasible [17]. To avoid these high costs accompanying transmission via national grids, decentralized energy systems can be used [18]. Small-scale hydropower, wind, photovoltaic (PV), and diesel-engine generator are amongst the common off-grid electrification systems used in the developing regions; for instance in, Africa, the Caribbean, Latin America, and Asia [18]; nonetheless, most of the population in rural areas (>2.4 billion individuals worldwide), still rely on traditional fuels for cooking.

As discussed in [18], consideration of renewable energy systems (RES) as part of the remedy for rural electrification is of particular importance. This is because most of the previous attempts for conventional electrification of remote areas in developing countries were not successful. If the right policy is adopted, sustainable-development technology comprises an effective means for reducing energy poverty [17]. Solar, wind, and hydro technology are feasible and reliable energy sources. They can be used to generate off-grid electricity and assist in the rural-electrification capacity-expansion; nevertheless, the technical-, installation-, and social issues should be accounted for to ensure the project success [17]. Additionally, the importance of utilizing the Internet of Things (IoT) paradigm when integrating renewable energy sources into smart grids was discussed in the literature [20,21]. This provides a powerful tool for simultaneous monitoring and control of the resources. For instance, [22] provides a novel framework for state estimation in wind-turbine integrated grids.

Along with conventional Supervisory Control and Data Acquisition (SCADA) measurement methods, the IoT provides information about the resources in very short time frames, which can be utilized for control or monitoring purposes. Other literature investigated the use of IoT in energy-aware residential buildings [23]. Here, the IoT paradigm helps not only in appliance automation but also in monitoring household energy demand and remote control of appliances during peak and off-peak hours, which has tremendous economic value on the monthly rates of the household.

The shortcoming of remote areas being far from the capital cities can be utilized for our advantage, as it offers a large area of uninhabited land that can be used to build renewable systems. The government in Jordan should focus on maximizing the utilization of the available resources to decrease the dependency on fossil fuel. Jordan has a great potential of RES that can cover the country's energy needs

if implemented wisely, especially wind and solar resources [14,15,24–26]. However, solar and wind energies fluctuate with time. They do not match the demand profile, which forms a challenging issue related to energy security, power grid quality, and reliability of such systems [27]. The hybridization of solar and wind resources increases the reliability of the system and enhances the matching between demand and supply. Few studies investigated the potential of RES in Jordan. For instance, Essalaimeh et al. [28] found that the electricity generated by a combination of solar and wind energy grid-connected systems can be utilized for various types of applications, including space heating and cooling. Halasa and Asumadu [29] demonstrated the feasibility of having large scale wind and solar hybrid power systems in Jordan, where wind energy was placed in the mountains of Northern Jordan and Solar energy in the Eastern Desert. The installation costs were approximated to be US\$290 million for the 100 – 150 MW wind farm and US\$560 million for the 100 MW solar. Another study [30] proposed an off-grid hybrid solar PV and wind energy systems in two locations in Jordan, Alhasan industrial estate, and Alayn Albayda, taking economic, reliability, and sustainability measures into consideration.

Furthermore, a grid-connected hybrid system consisting of solar PV and wind turbines was proposed in [31]. The system was investigated at four different locations in Jordan, and results showed that it could power a small village in Jordan. However, in the latter study, no-optimization of the system's size or economic feasibility was performed. Also, the mismatch between the demand and supply was not considered. The kingdom is rich in solar and wind resources, and also has a considerable potential of hydropower in some regions that can be utilized to supply a significant part of the baseload demand [32]. As such, a tri-hybridization of solar PV, wind, and hydropower forms an effective and environmentally friendly solution that ensures energy security and, at the same time, contributes to the mitigation of greenhouse gases (GHGs) [33,34].

Al-Tafilah governorate, located about 112 miles to the southwest of Amman, the capital of Jordan, spans an area of 853 mi2. The population of the governorate is estimated to 106,000 people, which is about 1% of Jordan's population. This means a population density of 125 people/mi2 compared to 6827 people/mi<sup>2</sup> in the capital city, Amman [35,36], with a total annual electricity demand of 137 GWh. As presented in Kiwan et al. [37], the transition towards a 100% renewable energy grid in Jordan shall be gradual, and about 1/3 of the 2050 total capacity should be installed by 2030. This transition will help Jordan overcome its 94% energy-import dependency. Since Jordan is amongst the signatories to the Paris agreement, it will also help the country adhere to the set emissions limit by reducing its carbon dioxide production associated with electricity generation. In this work, the techno-economic feasibility of installing PV/wind-hydropower systems to supply and match 100% of the electrical demand in Al-Tafilah forecasted for the year 2030 was investigated. Multiple scenarios were considered, including the integration of an energy storage system. Sensitivity analysis was conducted to examine the effect of resources and demand variation, RES costs, and annual discount rate on the techno/economic performance of the system. It's also worth noting that the expansion of this work to other similar areas in Jordan is possible, as Kiwan et al. [37] showed other rural cities, like AlMafraq and Maan, represent sites of highest hybrid RES potential. Hence, Al-Tafilah signifies the more challenging case towards a 100% renewable energy grid and is therefore considered here. As such, the presented study will not only set forth a decentralized system that will suffice the city of its energy needs while mitigating the issues mentioned above of centralized grids. It will also open the doors for consideration of rural renewable decentralized systems as part of the 2030 projection for the 100% renewable transition presented by Kiwan et al.

#### **2. System Description and Methodology**

#### *2.1. RES Description*

#### 2.1.1. Solar Energy System

The ambient conditions of the location where the PV plant is installed affect the efficiency of the PV module and hence the energy production. As the module temperature increase, the PV efficiency decreases, and so does the amount of produced energy. By neglecting the effects of relative humidity and wind speeds and considering the effect of the ambient temperature, the efficiency of the PV module can be estimated using Equation (A1) shown in Appendix A.

The specifications of the PV modules are vital for the estimation of the energy output from the PV system. In this study, a Canadian Solar company type CS6K-285M modules were used. Obtaining the global insolation on the PV module in addition to the module efficiency is necessary for the estimation of the energy produced. The estimation of the global insolation was achieved using the methodology presented by Duffie and Beckman [38], which was not included here for brevity. The hourly energy generated from the PV power plant, Ep, can be calculated, as shown in A.2. The hourly solar resources, as well as the hourly ambient temperature for Al-Tafilah, were obtained using Meteonorm software, which provides the data based on Typical Metrological Year (TMY).
