Techno-Economic Feasibility of Grid-Connected Solar PV System at Near East University Hospital, Northern Cyprus

Abstract

The growth of populations and economy in Northern Cyprus has led to continuing utilization of fossil fuels as the primary source of electricity, which will raise environmental pollution. Thus, utilizing renewable energy, particularly solar energy, might be a solution to minimize this issue. This paper presents the potential of grid-connected solar PV power generation at Near East University Hospital (NEU Hospital), one of the largest and leading medical facilities in Northern Cyprus, to meet the energy demand during the daytime to reduce energy bills. For this purpose, the first objective of the study is to evaluate the solar energy potential as a power source for the NEU Hospital based on four datasets (actual measurement, Satellite Application Facility on Climate Monitoring (CMSAF), Surface Radiation Data Set-Heliosat (SARAH), and ERA-5, produced by the European Centre for Medium-range Weather Forecast). The results showed that the solar resource of the selected location is categorized as excellent (class 5), that is, the global solar radiation is within the range of 1843.8–2035.9 kWH/m². The second objective is to investigate the impact of orientation angles on PV output, capacity factor, economic feasibility indicators, and CO₂ emissions by using different PV modules. The results are compared with optimum orientation angles found by Photovoltaic Geographical Information System (PVGIS) simulation software. This objective was achieved by using RETScreen Expert software. The results demonstrated that the highest performance of the proposed system was achieved for orientation angles of 180° (azimuth angle) and −35° (tilt angle). Consequently, it is recommended that orientation angles, PV modules, and market prices are considered to maximize energy production and reduce electricity production costs.

1. Introduction

Due to the growing population, the number of buildings has increased, leading to increased energy consumption and greenhouse emissions that rely mainly on fossil fuels. Therefore, many scientific researchers found that renewable energy, such as solar and wind energy, is a good solution to reduce greenhouse gas (GHG) emissions. For instance, Lazarous et al. [1] concluded that utilizing zero-emission energy production such as renewable energy will help achieve Paris Agreement requirements via substantial reduction of carbon emissions. Schnitzer et al. [2] concluded that utilizing solar thermal energy provided an essential step towards sustainable zero-emission production in the industry. Shahsavari and Akbari [3] found that renewable energies have high potential for reducing GHG emissions.

Thus, solar power has been considered as one of the main potential, economically viable, and environmentally friendly energy sources among renewable energy sources. Many studies have investigated the potential for generating electricity with photovoltaic (PV) systems in different locations worldwide. For example, Nassar and Alsadi [4] evaluated solar energy potential in Gaza Strip, Palestine, utilizing hourly solar radiation data. The results indicated that Gaza Strip has high potential for generating electricity from solar energy due to the high value of direct normal irradiance and global tilted irradiance. Martín–Pomares et al. [5] evaluated Qatar’s long-term solar energy potential as an electricity generation source. The results showed that Qatar’s large-scale PV grid-connected plant could be considered an alternative solution for electricity generation. Almarshoud [6] investigated the PV system performance in different locations in Saudi Arabia using measured solar irradiance data. It is found that the Najran has the highest solar energy among 32 locations, while the lowest solar energy potential was recorded in Qunfudhah. Lau et al. [7] evaluated the solar energy potential in Dares Salaam, Tanzania, based on the solar irradiance models. The results demonstrated that solar energy could help improve the living quality in the area by reducing fossil energy consumption from fossil fuel. Mardonova and Choi [8] investigated the solar energy potential in mining sites in Uzbekistan to install 1 MW PV systems. The results showed that the iron mine Tebinbuloq in Karakalpak has the highest solar potential compared to other sites. Al Ghaithi et al. [9] analyzed the viability of off-grid solar PV systems in Masirah Island, Oman. The results indicated that a hybrid energy system including wind, photovoltaic, and diesel generators were the most economically feasible option and improved the voltage profile at the connection point.

Moreover, numerous researchers have focused on solar PV systems’ solar energy potential and viability as power generation sources in buildings, like hospitals, departments, and more [10,11,12,13,14,15,16,17]. For instance, Al-Najideen and Alrwashdeh [10] designed a 56.7 kW grid-connected PV system to cover the demand for electricity in the Faculty of Engineering at Mu’tah University in Jordan. The results showed that the proposed PV system would reduce the electricity bill and cover the faculty’s energy demand. Manoj–Kumar et al. [11] investigated the feasibility of a 1 MW PV system at two different campuses of Universiti Malaysia Pahang based on simulation results collected from PVGIS and PVWatt software. They found that the proposed project would meet 50% of its energy requirements during the daytime, and the university could save around RM 700,699 annually. Alghamdi [12] investigated the feasibility of a grid-connected-diesel generator-PV system for a hospital building in Dammam, Saudi Arabia. The results demonstrated that utilizing the grid-connected PV system in the hospital was a feasible and lower solution than the conventional grid and standby diesel engine system. Imam et al. [13] explored the potential of a grid-connected PV system for typical residential buildings in Jeddah, Saudi Arabia. The results showed that the proposed PV system produced 87% of the electricity needs of the building. Carlos et al. [17] determined the practical potential for PV power generation in the Putumayo department of Colombia. They concluded that the PV system could cover the department’s consumption by producing self-generating electricity and distributed generation. In the end, the scientific researchers concluded that utilizing renewable energy as a powerful energy source can reduce the total energy consumption and potentially provide a promising solution for reducing the energy demand for the building [10,11,12,13,14,15,16,17].

1.1. Solar Energy Potential in Northern Cyprus

Northern Cyprus has an area of 3354 km² and a population of about 326,000, and it has a Mediterranean climate. The power in Northern Cyprus is heavily dependent on non-renewable energy resources, and the production of electrical energy is mainly generated from four power plants [18]. In Northern Cyprus, there are four solar PV plants at Middle East Technical University Northern Cyprus Campus with a capacity of 1 MW (2015), Cyprus International University with a capacity of 1.3 MW (2016), KKTCell Main Building with a capacity of 50 kW (2017), and Levent College with a capacity of 120 kW (2018) [19,20].

Northern Cyprus has vast solar energy potential. The highest and lowest annual values of global horizontal irradiation in Northern Cyprus are estimated at 2000 kWh/m² and 1800 kWh/m², respectively. These values indicate that the solar resource is classified as good (class 4) and excellent (class 5) according to Kassem et al. [21] and Prăvălie et al. [22]. Additionally, the maximum and minimum values of direct normal irradiation are about 2230 kWh/m² and 1710 kWh/m², respectively. Thus, solar energy potential for Northern Cyprus is classified as good, excellent, and outstanding based on DNI values [21,22]. In the end, it can conclude that all regions in Northern Cyprus have a vast resource energy potential for generating energy from flat-plate PV and concentrating PV systems. Additionally, it should be noted that the solar radiation intensity is varied in different regions. Besides, İlkan et al. [23] concluded that solar power systems could be alternative sources to fulfill the electrical power required and reduce the CO₂ emissions in the country. Pathirana and Muhtaroglu [24] concluded that utilizing solar energy in Northern Cyprus can help to produce power and become more independent from fossil fuels. Radmehr et al. [25] found that Northern Cyprus has a remarkable ability to utilize building-integrated PV systems as a power source in the house. Agboola and Egelioglu [26] concluded that solar energy could be considered an alternative solution to reduce the energy demand and water scarcity in Northern Cyprus.

Furthermore, several authors have studied the potential of solar energy and techno-economic feasibility of PV systems in different regions in Northern Cyprus, as shown in

Table 1. Summary of previous studies focusing on solar energy potential in Northern Cyprus.

Reference	Year	Description/Aim	Remarks and Key Findings
[27]	2011	Feasibility of a 1 MW grid-connected PV system in Nicosia (Lefkoşa), Morphou (Güzelyurt), and Rizokarpaso (Dipkarpaz)	The feasibility of a two-axis PV system was higher than a fixed-structure solar system
[28]	2012	Evaluate and compare the use of the solar thermal energy collectors (Parabolic Trough and Fresnel systems) over Northern Cyprus topography	Fresnel systems have an advantage over Parabolic Trough due to higher solar irradiation absorption, lower CO2 emissions, and lower operating cost.
[29]	2014	Installing a 30 MW hypothetical solar chimney power plant under Northern Cyprus conditions	The annual electrical energy from the proposed system was estimated to be 94.5 GWh. This amount of energy output would contribute significantly to meeting 22,128 residences household’s electrical energy demand.
[30,31]	2015	Build 1.275 GW PV plant in Serhatköy site	The plant will improve the electricity sector and will be able to reduce emissions to an acceptable level.
[32]	2016	Design and techno-economic analysis of a standalone PV system to meet the electricity of a house in the rural fringe of Famagusta	The electricity generation cost was 0.73 TL/kWh, and the developed system is a viable technology for the electrification of a house in Cyprus.
[33]	2016	The performance and economic viability of two different PV plants (Fixed-tilt and parabolic trough) with a capacity of 40 MW in Nicosia and Famagusta	The highest profitability was found in Nicosia, and utilizing solar power plants will help to reduce large amounts of CO2 emissions.
[34]	2017	Develop a hybrid system to generate electricity for a household in Nicosia	The hybrid system is considered an economical option for electricity generation in the selected location.
[35]	2018	Develop a 12 MW grid-connected wind farms and fixed-tilt PV power plants in Lefkoşa and Girne	The selection locations were found suitable to build a PV system for energy production and reduce fuel consumption.
[36]	2018	Propose a 1 MW grid-connected PV power plant with the various sun-tracking systems in Lefke town	The electricity cost was found within 0.109–0.150 $/kWh, and annual GHG emission reduction was varied from 1321 to 1829 tCO2.
[37]	2018	Investigate the utilizing of solar energy Famagusta (Gazimağusa) city	Famagusta City has huge potential for solar energy, but the city is not able to generate the required amount of solar energy because of its inappropriate urban design
[38]	2018	Find the best location for installing a PV power plant based on the highest profitability of the project.	Güzelyurt region has the highest solar energy potential and economic feasibility to install a PV power plant in the future.
[39]	2018	Propose a 4.85 kW grid-connected PV rooftop systems in Nicosia (Lefkoşa), Morphou (Güzelyurt) and Dipkarpaz	All selected locations have a higher potential for solar energy
[40]	2019	Develop a 6.4 kW grid-connected PV wind systems for household in Lefkoşa, Girne and Gazimağusa	The PV systems are an economical option for generating electricity in the selected location compared to wind systems.
[41]	2019	Propose a 45 kW rooftop-building grid-connected PV power system in Lefke town	The electricity cost of the proposed system was found to be 0.056 $/kWh, which is lower than the energy cost of traditional energy (0.15 $/kWh)
[42]	2019	Using of PV as a shading device for solving the heating problems in the residential sector in Famagusta	The developed system produced around 50% of the electricity needs of the building
[43]	2019	Present the performance assessment of 110 kW grid-connected solar system with various PV technologies	The CdTe PV system has a higher performance ratio than other PV technologies, and the proposed system can help reduce the green gas emissions and supply electricity to the Near East University.
[44]	2019	Present the performance assessment of 110 kW grid-connected solar system at a different location in Northern Cyprus	The annual average performance ratio was within the range of 75–80% for all PV technologies.
[45]	2019	Techno-economic feasibility evaluation for a solar-powered seawater desalination plant in Güzelyurt	The proposed system can be considered as a good solution for solving water scarcity and reducing greenhouse gas emissions.
[46]	2019	Technical, environmental and economic aspects for developing PV/wind hybrid system in Middle East Technical University Northern Cyprus Campus	The proposed system will reduce the annual fuel consumption of the island by 9920 barrels which will also reduce the annual CO2 emissions by 3622 tons.
[47]	2020	Develop a 30 kW grid-connected PV system for Near East University grand library with various types of PV systems used on building PV technologies	The performance of freestanding mounting position system with thin-film (CdTe) was found better than building-integrated PV.
[48]	2020	The feasibility of 100 MW grid-connected PV plant in Lefkoşa	The proposed system would help to reduce fuel consumption, electricity tariffs, and greenhouse gas emissions
[49]	2020	Develop a 6 kW PV-Wind hybrid system to meet a single household electricity demand in Güzelyurt	The proposed system helped to reduce the electricity bill of the household.

. Based on the previous studies (Table 1), it can be concluded that utilizing solar energy can be an alternative solution for reducing fuel consumption, water scarcity, and greenhouse gas emissions.

1.2. Importance of the Study and Research Gap

According to the Ref. [50], the Turkey–Northern Cyprus electricity project will be a similar Turkey–Northern Cyprus water project that aims to supply electricity from Turkey to Northern Cyprus. Therefore, utilizing renewable energy systems can be an alternative solution for generating electricity on the island and reducing gas emissions to an acceptable level.

The literature reveals an evident lack of forecasting energy and economic benefits of the grid-connected PV system to reduce energy consumption, which relies on fossil fuel and decreasing air pollutants for a hospital building in Northern Cyprus. Additionally, most works related to Northern Cyprus studied the techno-economic feasibility of standalone, grid-connected, and hybrid systems for different regions in Northern Cyprus. Moreover, in the available literature, the scientific researchers have focused on finding the optimum angles (tilt and azimuth angles) of fixed PV systems for different solar energy applications in certain areas around the world, for example, Saudi Arabia [51], Brisbane, Australia [52], Abu Dhabi, United Arab Emirates [53], and Palestine [54]. Besides, numerous researchers concluded that the optimum orientation angles (tilt and azimuth angles) of fixed solar modules help maximize the performance of fixed-tilted PV systems and reduce greenhouse gas emissions [55,56,57,58,59,60,61,62,63]. Additionally, various theoretical models and simulation tools have been utilized to estimate the optimum orientation angles for the fixed-tilt PV system [51,58]. Thus, according to the authors’ review, the available literature does not explicitly concentrate on the impact of the orientation angle accuracy of the PV system on energy production, capacity factor, economic feasibility indicators, and CO₂ emissions in Northern Cyprus.

As a continuation of authors’ studies on the performance, economic viability, and environmental sustainability of solar PV technology in Northern Cyprus, this study had the goal of putting forward the new investigation to achieve an economic and environmental feasibility study of using green and clean energy provided by solar photovoltaic (PV) modules for the Near East University Hospital located in Lefkoşa, Northern Cyprus. This study has been focused on two objectives. Due to the limitation of meteorological stations in Northern Cyprus, the first objective is to ensure that the meteorological data of Lefkoşa can be considered constant and used for forecasting the solar energy potential for Near East Hospital. In order to work on the first objective, four datasets (actual measurement, Satellite Application Facility on Climate Monitoring (CMSAF), Surface Radiation Data Set-Heliosat (SARAH), and ERA-5, produced by the European Centre for Medium-range Weather Forecast) are compared and analyzed regarding their accuracy and provide a comparative analysis for estimating the potential of solar energy in the selected location. The second objective is to investigate the impact of orientation angles (azimuth and tilt angles) on PV output, capacity factor, economic feasibility indicators, and GHG emissions. The results are compared with optimum orientation angles found by PVGIS (Photovoltaic Geographical Information System) simulation software. This objective was achieved by using RETScreen Expert software.

2. Materials and Methods

The solar energy potential in the Near East University Hospital is presented in this section. Furthermore, the techno-economic feasibility of grid-connected PV plants in the selected location is discussed. Figure 1 illustrates the analysis procedure of the current study.

2.1. Energy Situation at the Near East University Hospital

The proposed location is located in Near East University, a private university located in Lefkoşa, Northern Cyprus (Latitude: 35.229 and Longitude: 33.320). Near East University Hospital was open to public use in 2010 after construction in 2008 as the first and only private university hospital with 36 service departments equipped with high technology. The hospital building, which has an indoor space of 55,000 m², is situated within the Near East University Campus in Nicosia. The building consists of three blocks with three, four, and nine stores. There are 209 single-bed patient rooms, eight surgery rooms, 30 intensive care units, and 17 newborn intensive care units. Apart from that, it is the only hospital with a high-tech Radiotherapy center and only a PET/CT Scanner. Moreover, it has been fully equipped with laboratories to carry out all medical tests and RIS (Radiology Information System) and LIS (Laboratory Information System). The Faculty of Medicine also uses the hospital building to carry out lectures and practices. In addition to the hospital, the building also provides accommodation for students with 60 rooms. Figure 2 shows a panoramic view and architectural overview of Near East University Hospital.

The electricity consumption data are measured and recorded using a powerful automation system device with Azeotech DAQFactory HMI/SCADA Software installed at Near East University (NEU) hospital. The study involved collecting and analyzing the historical hourly electricity consumption data and electricity costs for January 2017 to December 2018 to evaluate the tendency of electricity demand.

Figure 3 illustrates the monthly electricity composition and costs during the investigated period. It was found that the highest electricity demand was recorded in the summer (June, July, and August) and autumn (September, October, and November) seasons, ranging from 6540.655–9978.682 kWh for 2017 and 6935.316–10,635.170 kWh for 2018. During this period (summer and autumn seasons), the average, minimum, and maximum temperatures are within the range of 15.57–38.72 °C, 11.69–28.41 °C, and 32.83–13.60 °C for 2017 and 18.27–35.15 °C, 14.40–28.11 °C and 331.28–16.30 °C for 2018, respectively, according to the National Aeronautics and Space Administration (NASA) database. Because of a higher temperature, the usage of air conditioners for cooling increased. Furthermore, it can be seen that the annual electricity bill in 2017 and 2018 for NEU hospital was 1.41 and 1.86 million TL in 2017 and 2018, respectively. As shown in Figure 3, the electricity bill increased by 31.91% due to new technologies with a high quality of care, and technically advanced facilities attracted patients. It can be concluded that NEU hospital suffers from high electricity bills exceeding 1.860 million TL/year.

2.2. Data

The accurate measurement of the solar resource at the selected location is not available due to the meteorological stations in Northern Cyprus. Additionally, the measurement data, such as solar radiation and air temperature, are essential factors to estimate the performance of PV systems [64]. According to Maammeur et al. [65] and Akinsipe et al. [66], the size of a PV plant can be determined based on the highest value of global solar radiation. Moreover, according to Bhatia [67], solar radiation can be assumed to be constant in large areas, neglecting cloud absorption’s effect on solar radiation. As mentioned previously, the actual measurement data (solar radiation, air temperature) are not available for the selected location; thus, it is considered one of the critical limitations of this present study.

Therefore, the meteorological data (global solar radiation, sunshine duration, relative humidity, and ambient temperature) of NEU hospital are assumed to be the meteorological data of the Lefkoşa. To achieve this:

• The hourly meteorological data of the Lefkoşa location are compared with three databases, namely, the Satellite Application Facility on Climate Monitoring (CMSAF), Surface Radiation Data Set-Heliosat (SARAH), and ECMWF ERA-5 produced by the European Centre for Medium-range Weather Forecast to show the accuracy of the database. In general, the accuracy of the satellite database is enough to decide on the design of the solar PV system [68].
• Based on the results of the first criteria, the satellite database of the Lefkoşa location and NEU hospital location are compared to verify that both values are closed to each other, and to verify that solar radiation can be considered constant in a wide area.

The meteorological data and satellite database were gathered from January 2014 to December 2016.

2.3. On-Grid Solar PV System

2.3.1. PV System Sizing

In this work, grid-connected PV plants were developed to cover the energy demand at NEU hospital during the daytime. Thus, the PV energy amount injected into the grid ($E_{inj}$) should be greater than the electricity amount purchased by the system from the grid ($E_{abs}$) as expressed in Equation (1) [69].

$$E_{inj}>E_{abs}$$

(1)

It should be known that the hospital is considered as a micro-grid, which can produce parts of its energy by solar energy and the remaining energy from the grid.

Generally, the grid-connected PV system consists of PV modules, an inverter, distribution controller, and load. According to the previous studies [70,71], utilizing the grid-connected PV systems helps to reduce the energy consumption, capacity losses in the utility distribution network and delays upgrades to the transmission and distribution (T&D) network. Furthermore, the developed system is not dependent on the battery type used and required capacity [72]. Thus, this system can be considered as an economic benefit for reducing system costs.

As mentioned previously, the maximum power ($P_{max}$) of the proposed plant using Equation (2) [65] is:

$$P_{max}=\frac{E_{AC}{P}_i}{G_{SR}{f}_{PV}{\eta }_{inv}}$$

(2)

where $P_i$ is the solar radiation at STC in kW/m², $G_{SR}$ is the global solar radiation (kWh/m²/d), $f_{PV}$ is the PV derating factor, $E_{AC}$ is the daily power consumption in kWh/d, and ${\eta }_{inv}$ is the inverter yield.

2.3.2. PV-Module Selection and Inverter

There are many different PV modules, such as mono-crystalline, poly-crystalline cells and amorphous silicon modules in the Turkey and Northern Cyprus market. Hence, cell type, system cost, the warranty, and the size and watts are required parameters to select the suitable PV module [73]. Besides, Balo and Şağbanşua [74] concluded that the PTC (PV USA Test Conditions) power rating and material type are essential factors for selecting solar panels. Rehman et al. [75] found a suitable PV panel based on the ratio of module capacity to its price and module area. Recently, El-Bayeh et al. [76] concluded that the characteristics of the PV module (module area, power rate, cost, and efficiency) are one of the essential categories for developing a PV system. Moreover, Sasikumar and Ayyappan [77] found that the power rate and weight of the panel are the most important criteria for selecting the best solar panel.

Consequently, Equation (3) was utilized to select the suitable PV-module for the proposed PV plant. It should be known that the efficiency of the PV modules, which are selected in this study, is above than 16%.

$$\mathrm{Panel}\mathrm{selection}=\frac{PV module capacity\times Module \mathrm{efficiency}}{ module price\times Frams area of the module}$$

(3)

Table 2. Selection criteria ratio for PV modules.

Manufacturer	Module Type	Maximum Power [W]	Efficiency [%]	Module Area [m2]	Module Price [$]	Selection Term
Jinko	JKM330M-60-V	330	19.78	1.668	115	34.03
Solar Fabrik	-	340	20.14	1.687	237	17.13
Panasonic	-	325	19.40	1.674	257	14.66
Ankara Solar	AS-M60-310W	310	19.00	1.630	77	46.93
AXITEC	AC-430MH/144V	430	19.33	2.174	120.4	31.76
Suntech	STP325-24/Vfw	335	17.20	1.944	81	36.59
SunLink	-	435	20	2.1073	105	39.32
AIONRISE	AE410HM6-72	410	20.66	1.674	115	44.00
Tide Solar	-	450	20.40	2.208	90	46.20
Regitec Solar	RMH60/380S1	380	20.9	1.853	110	38.96
Austa Energy	AU410-27V-MHB	410	20.97	1.955	99	44.42
Horay Solar	HS166-380-120M	380	20.50	1.823	84	51.11
München Energieprodukte GmbH	-	440	19.9	2.209	110	36.03
Fortunes Solar	FDS-M6M-60-355BK	355	19.26	1.868	82	44.64

lists the PV modules from different manufacturing companies in Turkey and Northern Cyprus. Among the 14 solar panels, it is found that the panel, which was manufactured by Horay Solar and Ankara Solar, are the most suitable, with a performance score of 51.11 and 46.93, respectively.

Table 3. Specification of the used PV modules at Standard Test Conditions.

Item	Specification
Manufacturer	Horay Solar	Ankara Solar
Model	HS166-380-120M	AS-M60-310W
Maximum Power (Pmax) [W]	380	310
The voltage at Maximum Power (Vmp) [V]	34.5	31.7
Current at Maximum Power (Impp) [A]	11.04	9.8
Open Circuit Voltage (Voc) [V]	41.7	39.7
Short Circuit Current (Isc) [A]	11.55	10.12
Operating Temperature Range [°C]	−40~85	−40~85
Temperature Coefficient of Pmax [%/°C]	−0.36	−0.41
Temperature Coefficient of Voc [%/°C]	−0.28	−0.31
Temperature Coefficient of Isc [%/°C]	0.05	0.05

summarizes the specification of the selected module.

Moreover, the inverter is an electrical converter that converts the produced direct current for the PV panel into alternating current fed into the commercial electrical grid. There are several types of inverters in the market. The output AC power, DC–AC conversion efficiency, and capital cost are considered essential factors for selecting a suitable inverter. Thus, two units of central inverters of Sunny Central 850CP XT with a capacity of 954 kW and 98.6% efficiency were utilized. The characteristics of the used inverter are available from the Ref. [78].

2.3.3. Simulation Tool

There are many simulation tools, such as RETScreen, HOMER, PVsyst, TRANSYS, and so on to estimate the performance of PV power plants. The comparison between these simulation tools is available from the Ref. [79]. In recent years, RETScreen has been widely used to analyze different renewable energy infrastructures and their feasibility. RETScreen was developed by Natural Resources Canada (NRC). It aims to estimate the energy production and savings, costs, emissions reduction, financial viability, and risk of various renewable energy technologies. The RETScreen utilizes the long-term monthly average meteorological data from the National Aeronautics and Space Administration (NASA) database to source meteorological information for the specific location. It is a rapid and efficient tool for examining the renewable energy system’s energy performance and for environmental impact reduction. It has many advantages, such as being relatively easy to use, being free, and accurately evaluating both electrical and thermal systems [80,81].

In the literature, many research papers studied the techno-economic of grid-connected PV systems using RETScreen software. For instance, Mardonova and Choi [8] utilized the RETScreen software to estimate the PV systems’ energy production, greenhouse gas reduction, and financial factors in a different location in Uzbekistan. Ahmed et al. [58] used the software to analyze the impact of orientation angles on the PV output of the proposed system. Mondal and Islam [70] used the software to examine the economic feasibility of a 1 MW grid-connected PV plant in Bangladesh. Sreenath et al. [82] used the software to perform the energy, economic and environmental analysis of conceptual 5 MW land-based solar photovoltaic power plants in different locations in Malaysia. Owolabi et al. [83] used RETScreen software for the techno-economic feasibility of a 6 MW grid-connected PV plant in various locations in the northeastern state of Nigeria. Kassem et al. [84] studied the feasibility of a 4.2 MW grid-connected PV plant in 25 selected coastal Mediterranean cities located in different Arabic countries using RETScreen software. Sreenath et al. [85] assessed solar photovoltaic power plants’ energy generation, economic, and environmental performance in seven airports by utilizing RETScreen software. Farangi et al. [86] determined the technical, economic, and environmental aspects of the 20 kW and 1 MW grid-connected PV system in Iran using RETScreen software. Cristofari et al. [87] utilized the software to analyze the energy performance of the building-integrated solar thermal system. Li [88] investigated the techno-economic feasibility of a 1 MW grid-connected PV system in Jiangsu Province, China using RETScreen software. Ahmed et al. [89] utilized RETScreen software to investigate the environmental issue’s impact on the energy of PV system and GHG mitigation potential.

In the present study, RETScreen software was used to evaluate the techno-economic feasibility of the grid-connected PV development. Additionally, it was utilized to investigate the impact of orientation angles on the PV power output, capacity factor (Equation (4)), economic feasibility indicators such as Net present value (Equation (5)), Levelized cost of energy (Equation (6)), Simple payback (Equation (7)), Equity payback (Equation (8)), Annual life cycle savings (Equation (9)) and greenhouse gas (GHG) emissions (Equation (10)). It should be noted that these economic feasibility indicators were estimated to assess the benefits of investment and profitability of the proposed PV project. Additionally, RETScreen is capable of estimating these indicators.

Capacity factor (CF)

$$CF=\frac{P_{out}}{P\times 8760}$$

(4)

Net present value (NPV)

$$NPV={\displaystyle \sum }_{n=0}^N\frac{C_n}{{\left(1+r\right)}^n}$$

(5)

Levelized cost of energy (LCOE)

$$LCOE=\frac{sum of cost over lifetime}{s of electricity generated over the lifetime}$$

(6)

Simple payback (SP)

$$SP=\frac{C-IG}{\left(C_{ener}+C_{capa}+C_{RE}+C_{GHG}\right)-\left(C_{o\&M}+C_{fuel}\right)}$$

(7)

Equity payback (EP)

$$EP={\displaystyle \sum }_{n=0}^N{C}_n$$

(8)

Annual life cycle savings (ALCS)

$$ALCS=\frac{NPV}{\frac{1}{r}\left(1-\frac{1}{{\left(1+r\right)}^N}\right)}$$

(9)

Annual GHG emission reduction (A−GHG)

$$\begin{gathered} A-GHG=\left[\left(Base case GHG emission factor\right) \\ \hspace{1em}\hspace{1em}\hspace{1em}\hspace{1em}\hspace{1em}\hspace{1em}\hspace{1em}\hspace{1em}-\left(Proposed case GHG emission factor\right)\right] \\ \hspace{1em}\hspace{1em}\times End use energy delivered \end{gathered}$$

(10)

GHG emission reduction cost (GHG−E−RC)

$$\mathrm{GHG}-\mathrm{E}-\mathrm{RC}=\frac{ALCS}{{\Delta }_{GHG}}$$

(11)

Benefit–Cost ratio (B−C)

$$B-C=\frac{NPV+\left(1-f_d\right)C}{\left(1-f_d\right)C}$$

(12)

where $P_{out}$ is the energy generated per year,$P$ is installed capacity, N is the project life in years, $C_n$ is the after-tax cash flow in year n, r is the discount rate. C is the total initial cost of the project, $f_d$ is the debt ratio, B is the total benefit of the project, $IG$ is the incentives and grants, and $C_{ener}$ is the annual energy savings or income. $C_{capa}$ is the annual capacity savings or income, $C_{RE}$ is the annual renewable energy (RE) production credit income, $C_{GHG}$ is the GHG reduction income, $C_{o\&M}$ is the yearly operation and maintenance costs incurred by the clean energy project. $C_{fuel}$ is the annual cost of fuel, which is zero for renewable projects, and ${\Delta }_{GHG}$ is the annual GHG emission reduction.

3. Results

3.1. Characteristics of Global Solar Radiation

3.1.1. Comparison of Satellite Database with Actual Data for Lefkoşa

In this section, the actual data (global solar radiation (GSR)) are compared with different satellite databases (Satellite Application Facility on Climate Monitoring (CMSAF), Surface Radiation Data Set-Heliosat (SARAH), and ECMWF ERA-5, produced by the European Centre for Medium-range Weather Forecast) to show the accuracy of the estimated data. The comparison between the actual mean hourly of solar radiation (SR) and the estimated SR computed by the three products (SARAH, CMSAF, and ERA5) is illustrated in Figure S1 as supplementary material for Lefkoşa. Additionally, the R-squared, mean absolute error (MAE), and root mean squared error (RMSE) are determined to select the best product for estimating the mean hourly of solar radiation (see

Table 4. Performance evaluation of the products (SARAH, CMSAF, and ERA5).

Year	Statistical Indicators	Product
		SARAH	CMSAF	ERA5
2014	R-squared	0.9539	0.8276	0.9669
	RMSE	7.5109	10.0512	5.0139
	MAE	4.6397	6.5861	2.7992
2015	R-squared	0.9677	0.8144	0.9610
	RMSE	6.8053	10.3353	5.2303
	MAE	4.3925	6.7498	3.0006
2016	R-squared	0.9724	0.8195	0.9555
	RMSE	8.3007	10.4547	5.6626
	MAE	5.3651	6.7445	3.2477

). It is observed that the product ERA5 has produced the slightest error in terms of RMSE and MAE in estimating mean hourly solar radiation. Additionally, the highest value of R-squared is obtained by the product of ERA5. It has also been found that the CMSAF product has given the highest error values and lowest value of R-squared. In the end, the correlation between the satellite database and the measurement is highly accurate.

In the literature, GSR can be considered constant in a wide area when neglecting the effect of cloud absorption of solar radiation [67]. Therefore, the GSR of the selected location (NEU hospital) is compared with the GSR of Lefkoşa to verify that both values are close to each other (see Figure S2 as supplementary material). It is found that the monthly SR of NEU hospital is primarily close to the SR values Lefkoşa with minimum relative errors. The relative error between the SR of NEU hospital and Lefkoşa is within the range of −4.63 to 0.383 kWh/m² for CMSAF, −0.001 to 0.016 kWh/m² for ERA5, and −2.361 to 0.438 kWh/m² for SARAH. It is concluded that minimum relative error is obtained by the ERA5 product, which is considered the best product to analyze the characteristics of solar energy potential in the selected location.

It is concluded that the best dataset found in this study is ERA5 and has the lowest error compared to other products. Additionally, several researchers concluded that the estimated data have high accuracy and can be utilized to evaluate the solar energy potential at specific regions [90,91]. Moreover, the monthly GSR value of Lefkoşa and the selected location (NEU hospital) are close to each other. Therefore, it is concluded that meteorological data values can be considered constant values for a broad region.

3.1.2. Monthly and Hourly Global Solar Radiation, Sunshine Duration, and Ambient Temperature

The characteristics of hourly and monthly actual data (GSR, sunshine duration (SD), and average ambient temperature (AT)) for a period of 2014–2018 are presented in this section.

Figure 4 shows the trend of yearly global solar radiation (GSR) for the selected location. It is observed that there is a similar trend in different years. The diurnal mean GSR varies within a 24 h period for a selected location in Northern Cyprus, as shown in Figure 4a. It is found that the highest mean hourly GSR is recorded at 11:00 a.m. for whole years and varied from 6232 kWh/m² to 6503 kWh/m². Additionally, the highest monthly GSR belongs to June 2016, with a value of 248.554 kWh/m², as shown in Figure 4b. Moreover, it is found that the annual GSR is varied from 1938 kWh/m² to 2010 kWh/m² with an average value of 1966 kWh/m², as shown in Figure 4c. It is concluded that the solar resource of the selected location is classified as excellent (class 5), that is, the GSR is within the range of 1843.8–2035.9 kWh/m² according to the Refs. [48,49]. Therefore, NEU hospital is a suitable location for installing a solar PV plant in due to the highest values of solar radiation.

As presented in Figure 5, the maximum SD is recorded in July and August during the investigated period. Additionally, it is found that the minimum monthly sunshine duration of 272.7 min/day was found in December 2016 while a maximum of 716.3 min/day in July 2017, as shown in Figure 5b. Furthermore, it is found that the annual SD is varied from 5934 min/day to 6173 min/day with an average value of 6037 min/day, as shown in Figure 5c.

Additionally, the variations of average ambient temperature (AT) for the selected location are shown in Figure S3 as supplementary material. The AT variation during the day (see Figure S3a as supplementary material) can be divided into the following: between 00:00 h and 04:00 h, the AT values are the lowest and varied between 15.2 °C (at 04:00 h) and16.3 °C (at 00:00 h); between 05:00 and 12:00 h, the AT is ramping up to reach the maximum value of 26.3 °C at noon h; between 13:00 h and 23:00 h, the AT is declined and varied from 26.0 °C (at 13:00 h) and 16.8 °C (at 23:00 h). Additionally, it was found that the maximum and minimum monthly AT of 30.7 °C and 8.4 °C were recorded in July 2017 and January 2017, respectively, as shown in Figure S3b as supplementary material. The annual value of AT is within the range of 19.1–20.4 °C, as shown in Figure S3c as supplementary material.

As can be seen from Figure 4 and Figure 5, and Figure S3 as supplementary material, the mean GSR, SD, and AT characteristics may be somewhat different from year to year. Generally, more extended periods of weather parameters (GSR, SD, and AT) are preferable to obtain a quantitative, representative, and persuasive interpretation of weather parameters characteristics. Unfortunately, the long period of weather parameters is not available in this study. Thus, the relative error (RE) was calculated to account for the possible bias originating from insufficient actual data. The RE of each year is determined by using Equation (13) and illustrated in Figure S4 as supplementary material. The results indicate that during the five years, the maximum relative error occurs in the year 2016 (2.2%) for GSR, 2016 (2.3) for SD, and 2018 (3.9%).

$$RE=\frac{P_i-\overline{P}}{\overline{P}}\times 100\%,$$

(13)

where $\overline{P}$ denotes the annual mean weather parameter (GSR or SD or AT) of the concerned period and $P_i$ denotes the concerned year’s annual mean weather parameter (GSR or SD or AT).

3.2. Project Development and Financial Assessment

In general, the price of the PV system has constantly been dropping by 80% since 2009 [92]. Therefore, this drop has encouraged utilizing grid-connected solar PV systems as a powerful energy source for a specific location with high solar potential.

In this study, the installation of 1789 kW grid-connected PV systems is economically and environmentally analyzed using RETScreen software. It should be noted that it was found that the highest value of GHI of 7.822 kWh/m²/day was obtained in July, and the maximum daily power consumption for NEU hospital was found in the summer season 2018 with a value of 10.635 MWh/day. By using Equation (2), the value of $P_{max}$ was estimated to be 1789 kW. As mentioned previously, a grid-connected PV system does not depend on the battery type used and required capacity. Thus, the grid-connected PV system can be considered as an economic benefit for reducing system costs. Consequently, a fixed-tilt grid-connected PV system was used in this study as a solar shading of car parking. According to Al Awadhi et al. [93], solar shading of car parks can be installed practically anywhere, generate free electricity, and simultaneously provide shade. Figure 6 shows the details of the selected car parks in Near East University.

It should be noted that the main aim of the proposed project (1789 kW grid-connected PV system) was to reduce the energy bill and cover the energy demand for NEU Hospital during sunlight, while the use of power from the grid will be during the night or on cloudy, dull, and rainy days. Therefore, future research should be focused on estimating the size of the batteries needed to provide electricity to the NEU Hospital when the solar resource is not available, mainly at night.

3.2.1. Technical Viability

Based on the previous studies [94,95], the value of annual energy exported to the grid and capacity factor of the plant are dependent on solar radiation and the number of clear sunny days. Figure 7 illustrates the monthly variation of the daily solar radiation and clearness index for the selected location. It is found that the maximum value of daily solar radiation (DSR) is varied from 2.2 kWh/m²/day to 8.12 kWh/m²/day. The maximum and minimum values of DSR are obtained in June and December, respectively. Additionally, it is found that the annual average DSR is estimated to be approximately 5 kWh/m²/day for the selected location.

To find the highest value of solar radiance and the electricity exported to the grid, tilt and azimuth angles are varied from −55° to 55°.

Table 5. Daily solar radiation titled, annual solar radiation-tilted and the annual energy exported and the capacity factor for various tilt angle and azimuth angle = 0°.

Solar Panel used in the System	$\mathbf{Tilt}\mathbf{Angle}[°]$	Daily Solar Radiation Titled [kWh/m2/day]	Annual Solar Radiation-Tilted [MWh/m2]	Annual Energy Exported to the Grid [kWh]	Capacity Factor [%]
AS-M60-310W	20	5.63	2.06	2,835,190	18.1
	25 [31]	5.67	2.07	2,851,747	18.2
	30	5.67	2.07	2,853,019	18.2
	31 *	5.66	2.07	2,851,437	18.2
	35 [96]	5.63	2.06	2,838,998	18.10
	40	5.57	2.03	2,809,747	17.9
	45 [96]	5.47	2.00	2,765,404	17.6
	50	5.34	1.95	2,706,117	17.3
	55 [32]	5.34	1.89	2,633,554	16.8
HS166-380-120M	20	5.63	2.06	2,852,549	18.2
	25 [31]	5.67	2.07	2,869,207	18.3
	30	5.67	2.07	2,870,487	18.3
	31 *	5.66	2.07	2,868,895	18.3
	35 [96]	5.63	2.06	2,856,380	18.2
	40	5.57	2.03	2,826,950	18.0
	45 [96]	5.47	2.00	2,782,335	17.8
	50	5.34	1.95	2,722,746	17.4
	55 [32]	5.18	1.89	2,649,678	16.9

* estimated by PVGIS simulation tool.

lists the daily solar radiation tilted, annual solar radiation-tilted, and the annual energy exported along with the capacity factor for some selected tilt angle, and azimuth angle = 0°. It should be noted that the value of the tilt angle was chosen based on previous scientific studies [31,32,96]. Moreover, the optimum orientation angles (tilt and azimuth angles) can be found using a PVGIS simulation tool according to the Refs. [97,98,99]. For instance, Abdallah et al. [99] concluded that the slope angle and azimuth angle obtained by PVGIS is closed to calculated angles obtained by the mathematical equations. Thus, the optimum angles optimum slop angle for the proposed system is 31°. As shown in Table 5, it is found that the tilt angle of 30° gives the highest value of daily solar radiation titled, annual solar radiation-tilted and the annual energy exported to grid compared to other angles. Additionally, it is found that the value of annual energy exported to the grid and capacity factor is within the range of 2,633,554–2,853,019 kWh and 16.8–18.2%, respectively. According to the results obtained by [78,100,101], it is technically sustainable to construct a PV plant at NEU hospital.

As mentioned previously, orientation angles directly impact the performance and efficiency of the PV system. Thus, the impact of orientation (tilt and azimuth) angles on the annual average daily solar radiations, annual average solar radiations, annual energy exported to the grid, capacity factor (CF), and annual GHG emission reduction using various PV modules are presented in Figure 8 (HS166-380-120M) and Figure S5 as supplementary material (AS-M60-310W). These figures give the following findings:

The highest average annual daily solar radiation-tilted is obtained for a PV system that has a tilt angle of 25°, 30°, −25° and−30° and azimuth angle of 0° and 180°.

The highest annual solar radiations-tilted is obtained for a PV system that has a tilt angle of 25°, 30°, 31°, −25°, −30° and −31° and azimuth angle of 0° and 180°.

The highest annual energy exported to the grid (2998 MWh for module type of HS166-380-120M and 2980 MWh for module type of AS-M60-310W) is obtained from a PV system that has orientation angles of −35° (tilt angle) and 180° (azimuth angle).

The highest capacity factor (CF) of 19% is obtained from a PV system that has a tilt angle of −40°, −35°, −31° and −30° and azimuth angle of 180°.

The highest annual GHG emission reduction (2195.5 tCO₂/year for module type of HS166-380-120M and 2182.2 tCO₂/year for module type of AS-M60-310W) is obtained from a PV system that has orientation angles of −35° (tilt angle) and 180° (azimuth angle).

Using the HS166-380-120M module led to an increase in the performance of the proposed PV system by 0.6%.

Based on the findings, it can be concluded that the performance of PV systems is affected by the azimuth and tilt angles and the type of solar panel. In addition, this study found that the best azimuth and tilt angles to install a grid-connected PV system at Near East University Hospital are 180° and −35°, respectively. The monthly average electrical energy produced by the proposed PV system and the electrical energy purchased from the grid for optimum angels found by PVGIS (azimuth = −1° and tilt = 31°) software and the current study (azimuth = 180° and tilt = 35°) is shown in Figure 9. The results indicate that the PV system of 1789 kW almost covers the hospital load throughout the year, except for the following months of January, December, and July.

3.2.2. Economic Sustainability

In this section, the economic feasibility indicators are calculated using RETScreen software. These indicators are estimated based on the financial parameters, which are assumed based on the previous studies (

Table 6. Economic and financial parameters used for analysis.

Parameter	Unit	Value
PV module cost	$	77 (AS-M60-310W) 84 (HS166-380-120M)
Number of modules	-	5771 (AS-M60-310W) 4708 (HS166-380-120M)
The lifetime of the PV module	Year	25
Cost of each unit of inverter	$	155,647
Miscellaneous/contingency fund	% of the total initial cost	3
Installation and spare parts	% of the total initial cost	8.6
O&M cost	Annual	1.5 c$/kWh
Lifetime of inverter	Year	13
Feasibility study, development, and engineering cost	% of the total initial cost	0.6
Inverter replacement periodic cost	Every thirteen years	Equal to inverter’s cost
Inflation rate	%	8
Discount rate	%	6
Project life	Year	25
Energy cost increase rate	%	5
Reinvestment rate	%	9
Debt ratio	%	70
Debt interest rate	%	0
Debt term	Year	20

). Additionally, the cost of the developed system is also presented in Table 6. It should be noted that the economic and financial parameters of the system are estimated/assumed based on recent market data and is consistent with cost prices available in the literature.

According to previous studies [48,78,83,84], the NPV and payback period are important factors in evaluating economic viability. Thus, the main results regarding the economic performance of the 1789 kW grid-connected PV system for various orientation angles are illustrated in Figure 10. The results indicate that the proposed plant is financially and economically feasible based on the NPV value and the Refs. [78,83,84].

Generally, higher values of NPV and lower EP values is the most attractive combination. As shown in Figure 10, the most extended value of equity payback (EP) of 2.52 years was obtained for the proposed system used. AS-M60-310W has a tilt angle of −40° and azimuth angle of 0°, and lowest value of 1.10 for a tilt angle of −35° and azimuth angle of 180° if HS166-380-120M is used. Additionally, it was observed that the value of simple payback (SP) varied from 4.02 years to 7.10 years and 3.42 years to 6.03 years if AS-M60-310W or HS166-380-120M was used, respectively. The longest and lowest values of SP were recorded for tilt −40°, azimuth 0° and tilt −35°, azimuth 180°, respectively. These results indicate that the PV project in the selected location makes financial sense.

Moreover, the Benefit–Cost ratio (B–C) is a useful term used to estimate the viability of cash flows generated from the proposed project. According to Abdur–Rehman and Al–Sulaiman [102], the project is considered profitable when the B–C value is more significant than one. The comparative analysis shows that the orientation angles of −35° (tilt angle) and 180° (azimuth angle) had the highest value of B–C, followed by orientation angles of −31° (tilt angle) and 180° (azimuth angle). The value of B–C for all proposed systems indicated the feasibility of the projects. The orientation angles of −40° (tilt angle) and 0° (azimuth angle) had the lowest B–C value, as shown in Figure 10.

Additionally, ALCS is another term utilized to get an idea about the benefits of the project. This term is determined based on the NPV, lifetime of the project, and discount rate. The results of ALCS for all proposed projects are also illustrated in Figure 10. It was found that the ALCS values are within the range of 226,676–463,337 USD/year.

Furthermore, it was found that the value of energy production cost (EPC) is ranged from 0.0389 USD/kWh (tilt −40°, azimuth 0° for AS-M60-310W) and 0.0187 USD/kWh (tilt −35°, azimuth 180° for HS166-380-120M). Based on the result of EPC, the energy production cost of the proposed systems is competitive with the electricity company (Kibris Türk Elektrik Kurumu) tariff. The findings demonstrated the proposed project is economically acceptable due to the obtained favorable economic results.

4. Discussion

The analysis showed that the selected location has a high solar energy potential for the distribution of PV power systems. Based on the comparative study between ground-based measurement data and satellite-based solar data (Figures S1 and S2 as supplementary material), the results indicated that satellite-based measurement could be utilized in solar project studies where ground-based measurement data are not applicable. It should be noted that NEU Hospital is located in an area where ground measurements for solar radiance were not conducted. The selected location is located in Lefkoşa, where the ground-based measurement data were collected from the meteorological department. Based on the findings, the analysis demonstrated that the global solar radiation of Lefkoşa can be considered constant for a broad region based on the comparison between the ground-based measurement data and satellite-based solar data (Figures S1 and S2 supplementary material).

Due to rising electricity energy demand and reductions in the dependency on domestic power generators in Northern Cyprus, the feasibility of solar energy projects is limited (Table 1). Therefore, in the present paper, the feasibility of solar energy potential at NEU Hospital was investigated. This was achieved by finding the best orientation angles to maximize the performance of the grid-connected PV system and minimize the electricity production cost using RETScreen software. The results showed that the annual electrical energy from the proposed system at orientation angles of −35° (tilt angle) and 180° (azimuth angle) was within the range of 2980–2998 MWh. This amount of energy output would contribute significantly to meeting NEU Hospital’s electrical energy demand. Moreover, the proposed PV system was financially and environmentally efficient, with a payback period of three years and four months and a considerable reduction in CO₂ emissions.

5. Conclusions and Future Work

The present study examined the potential and viability of a grid-connected PV system at Near East University Hospital. The results indicated that the solar resource of the selected location is categorized as excellent (class 5), that is, the global solar radiation is within the range of 1843.8–2035.9 kWH/m². Furthermore, it was determined that the annual electricity generated from the proposed PV system was varied between 2,633,554 kW and 2,853,019 kW. Additionally, it was found that the electricity production cost was within the range of 0.0187–0.0389 USD/kWh. Therefore, the energy production cost of the proposed systems is competitive with the electricity company tariff. Moreover, the results indicated that the maximum performance of the proposed system was achieved for orientation angles of 180° (azimuth angle) and −35° (tilt angle). The conclusion in this paper has highlighted that the proposed system has many benefits, including reducing emissions, decreasing fuel use, and saving annually after a short payback period. In addition, this study demonstrates that the problem of the electricity crisis, which happens nowadays, can be solved by paying more attention to generating electricity from solar energy.

Finally, land availability was not taken into account in this study. Thus, measuring land availability for grid-connected PV plants will be our future research. A multi-criteria decision-making algorithm should be developed to become significant for selecting the best solar panel, which will help increase the system’s revenue. Besides, the effect of the financial parameters, including the discount rate and inflation rate, on the investment should be considered for future work. Moreover, the interaction between the distribution grid and the PV system should be investigated to understand the influence of grid-connected PV systems on the distribution grid.