Performance Evaluation of a MW-Size Grid-Connected Solar Photovoltaic Plant Considering the Impact of Tilt Angle

: This paper presents a study for the estimation of generation from a large-scale, grid-interfaced solar PV plant using the PVsyst software. This study aims to investigate the effect of tilt angle on the performance of the grid-integrated solar PV plant. Two types of tilt angle test plants, i.e., a ﬁxed tilt angle of 30 ◦ (1 MW) and two seasonal tilt angles, in summer 13 ◦ and in winter 30 ◦ (2.5 MW), have been selected at the same location in Bikaner, India. The performance of the proposed test solar power plants, rated at 1 MW (ﬁxed tilt angle) and 2.5 MW (two seasonal tilt angles), is established by comparing the results obtained using the PVsyst software with the practical data of annual solar insolation. It is established that the radiation incident on PV modules will increase by 2.41% if two seasonal tilt angles are considered. Hence, the annual capacity utilization factor (CUF) has increased by 0.26%. Furthermore, it is established that the proposed method’s performance is superior compared to the statistical methods reported in the literature.


Introduction
Solar insolation is the solar radiation incident on the earth's surface. This is converted to electrical energy using solar power plants and injected into the utility network. Recently, the share of power generated using solar photovoltaic (PV) power plants has rapidly increased in the Indian electricity grid, compared to the generation from thermal and nuclear power plants. The solar PV plants provide economic benefits, liberalization of the energy sector, and other advantages to electrical utilities, such as peak saving and support to the networks for the distribution and transmission utilities. Distributed interfacing of solar generation to the utility grid also reduces transmission and distribution losses [1]. Generally, stand-alone and small-sized grids connected to fallback solar PV plants are operated at low voltages, which range from 12 V to 48 V. This is due to the fact that storage batteries are operated at low-voltage, which makes the design of a stand-alone system at a • It is established that the performance of a solar PV plant with the seasonal tilt arrangement is better compared to the fixed tilt arrangement. This is achieved by the comparison of the performance of solar PV plants for both these arrangements using simulated PVsyst reports and the actual generation of two plants at the same location.
The same fact has also been established using the emulation generation data recorded in a real-time solar PV power plant.

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The impact of tilt angle on the performance of a grid-integrated solar PV plant is investigated. • A study was performed on a practical solar PV plant located at Bikaner, India considering the two types of tilt angle test plants, i.e., fixed tilt angle of 30 • (1 MW) and two seasonal tilt angles in the summer 13 • and in the winter 30 • (2.5 MW). • Practical performance is evaluated in the field and compared with the results computed using the PVsyst software. It is established that radiation incident on PV modules will increase by 2.41% if two seasonal tilt angles are considered. Hence, the annual capacity utilization factor (CUF) has been increased by 0.26%.
This paper is organized into nine sections. The introductions and research contributions are discussed in Section 1. The proposed methodology and test procedure are included in Section 2. Section 3 describes the test solar PV plants used for the study. The simulation results are discussed in Section 4. The emulation results of the test solar PV plants are discussed in Section 5. The performance, or yield assessment, of solar PV plant results on the test day is discussed in Section 6. The impact of tilt angle on yearly plant performance is investigated in Section 7. A performance comparative study is included in Section 8. Finally, conclusions are included in Section 9.

Methodology and Test Procedure
Energy yield is defined as the net AC energy output of the system generated hourly/ daily/weekly/monthly/yearly divided by the peak power of the installed PV array (Po) at STC (1000 W/m 2 solar irradiance, air mass 1.5 and 25 • C cell temperature) [37][38][39][40]. It indicates the number of hours of operation of the solar PV plant required per day at its rated capacity. Its units are kWh/kWp day. For energy yield assessment of solar PV plants, performance ratio (PR) and capacity utilization factor (CUF) are used.

Performance Ratio (PR)
PR is calculated as a percentage and describes the relationship between the real and the theoretical/possible energy output of a solar PV plant [36]. Performance ratio gives an indication of how efficiently the available solar energy (as per actual solar insolation) is converted into electrical energy by a solar PV plant. PR can be calculated on hourly/daily/weekly/monthly/yearly basis to continuously monitor the plant's performance. It accounts for all losses in the complete power generation system by taking actual value of units generated, which is influenced by many factors, with main factor being the temperature and low sun light. The PR equal to 75% indicates that 25% of the solar energy received by installed solar modules from the sun was not converted into electrical energy. IEC 61724 (2017) provides guidelines to calculate PR. The most significant and direct impacts on PV performance are due to the below-mentioned factors.

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In plane area, irradiance received by the PV array.
Shading losses due to soiling or snow.
Inverter clipping occurs when the inverter cannot output more than a pre-specified power [W]. It is equal to the curtailment of power, i.e., the network may not accept the available power. PR is defined by below detailed relation.
where Yf : measured total power generation output at the export energy (kWh) determined by expected total power generation on standard test conditions based on the total installed power capacity (kW) of the PV plant. Yr: total insolation measured at the PV Plant through the irradiance measurement equipment installed at the site in kWh/m 2 [39]. Yf is defined by below-detailed relation.
where P: the instantaneous power output of the array in kW. P STC : the STC rated plant capacity of the array in kWp, E: Energy output of the array in kWh. Yr is defined by below-detailed relation.
where G: the instantaneous irradiance measured in the plane of the array (POA) in W/m 2 , G STC : the STC irradiance, i.e., 1000 W/m 2 or 1 kW/m 2 , I: the insolation falling on the POA in Wh/m 2 or kWh/m 2 .

Capacity Utilization Factor(CUF)
CUF is the ratio of the total energy actually generated in kWh, compared with the theoretical energy in kWh that could have been generated in 365 days (8760 h) [41]. It does not consider the no-sun time of day of the 24 h. The CUF does not take into account any environmental or loss factors, like variation in irradiance, the de-rating or degradation of the panels, losses in the complete system, losses due to temperature rise, ohmic losses, grid outages, equipment outages, etc. The following formula is used to calculate the annual CUF: Hence, on one hand, PR is a measure of the performance of a PV system, taking into account environmental factors (temperature, irradiation, losses, etc.) and on the other hand, CUF completely ignores all these factors because it has installed plant capacity in its denominator. But in both cases, actual energy is generated in the numerator of the formula, and this actual energy generated value is based on all considerations including design, irradiance, losses, temperatures, and any other factor that influences the generation. Therefore, both factors have a significant status in study of performance of the plant.

Test Procedure to Investigate Impact of Tilt Angle on Generation and Performance Estimation of Solar PV Plant
To investigate energy yield due to seasonal variation and impact of tilt angle, the grid-connected solar PV plant situated at location (28.00 • N, 73.10 • E) Bikaner, which is a location in desert of India above the tropic of cancer is considered. The study and analysis of impact of tilt angle and the performance of grid-connected solar photovoltaic power plants. Work included in this paper is divided into the following steps: (1) Two types of grid-connected solar PV plants are considered, which are designated as Plant-1 (fixed tilt angle 30 • ) and Plant-2 (two seasonal tilt angles 13 • (summer), 30 • (winter)). These plants are based on configuration of large-scale grid-connected solar PV plant detailed in Figure 1. (2) Manually extract the parameters of power generation through SCADA system. Compare the monthly performance with the simulated results using PVsyst software. (3) To investigate the performance of both plants, the factors PR and CUF are computed using the data recorded on a particular test day of 17 October 2018 and annual data. In this procedure, the data extracted from SCADA are used to calculate PR along with CUF of that day, such as unit energy generation from inverter and solar insolation from pyranometer. (4) To check range of good generation days in a year, the unit/kW generation range of both the test plants is compared.

Description of Test Solar PV Plants
Grid-integrated solar PV plants are designed to operate in parallel with utility grids. In these systems, the inverter, or power conditioning unit (PCU), is the main component. The PCU converts DC power generated by the solar PV array into AC power of suitable voltage and quality so that it can be injected into the utility grid. The inverter of a solar PV plant must automatically stop injecting power when the utility grid is not energized (followed standard code UL 1741). This is an essential safety requirement for grid-integrated solar PV plants. A basic concept followed in a grid-integrated solar PV plant is illustrated in Figure 2.
The main components of a Grid solar power plant (MW capacity) are detailed below [3,37]:  In Figure 2, first a PV string is constructed by using the PV module as per system voltage, and then, by using SCB, all the power from the string is collected at a point using 4 or 6 mm 2 solar DC cable, and this collected power is transferred to the inverter using an underground cable. The inverter converts variable DC power to AC power. Due to the requirement for transferring this power to a GSS (grid substation), it is required that power be available at a high-voltage level of 33 kV. Hence, with the use of the power transformer, the inverter output voltage is stepped up to the 33 kV level. For the purpose of protection, a VCB (vacuum circuit breaker) is used with a protection current transformer (CT) and a potential transformer (PT) at the 33 kV voltage level. To isolate all elements of the solar PV plant from the GSS, an AC disconnector or isolator is used, which is operated only when the circuit is open-circuited by the use of the VCB to avoid flashover. Later, using a metering current transformer (CT) and a metering potential transformer (PT), a metering point is provided by the use of a transmission line. The power is transmitted to the GSS, where the infinity load is connected.
A SCADA system is able to monitor the real-time efficiency, indicating each and every parameter, such as the DC power input, AC power output, voltages, currents, weather reports, etc. This information can be used by the operation and maintenance (O&M) team to establish the general condition of the system and schedule urgent repair or maintenance activities such as cleaning, inverter room temperatures, and airflow. The plant is automatically operated and controlled by the SCADA system and is Open Platform Communications (OPC) compliant. There is a data logging, recording, and display system to continuously monitor the data for all parameters of the plant's DC/AC side. The SCADA shall be capable of communicating with all inverters and strings. It should have features for remote access to real-time data. The SCADA should be capable of generating a dayahead schedule of generation using historical data. Additionally, the system will send the telemetry data to the local state load dispatch center (SLDC). A computer-aided data acquisition unit consists of a transducer, an analog-to-digital (A/D) converter, a multiplexer, a (de) multiplexer, and interfacing hardware and software. All data shall be recorded chronologically date wise. Reliable sensors for solar insolation, temperature, weather, and electrical parameters are to be supplied with a data logger unit. SCADA shall measure and continuously record electrical parameters and provide data in 1-15 min' interval. The SCADA shall have features integrated with local systems, as well as remote stations via web using either a standard modem or GSM/wireless fidelity (WIFI) modem. The SCADA shall be provided with a reliable power supply, along with a backup supply for at least one hour to cater to the outage of the grid. The SCADA shall be compatible with the requirements for measuring and reporting the performance ratio (PR) and the capacity utilization factor (CUF) of the plant. The personal computer (PC)/printer (color)/workstation shall be of industrial type, rugged, and robust in nature to operate in a hostile environment. The PC will have a minimum of a 4th Generation Intel processor, and two 1 TB hard disk drives (HDD) with 4 GB RAM. The PC shall also have a 17" TFT color monitor. A DVD drive with a writer, a USB drive, a scroll mouse, and a UPS for 4 h power backup.
To investigate the performance of a solar PV plant, two types of grid-connected solar PV plants are considered, which are designated as Plant-1 (fixed tilt angle of 30 • ) and Plant-2 (two seasonal tilt angles of 13 • (summer), 30 • (winter)). These plants are installed at the same geographical location in Bikaner, India (28.00 • N, 73.10 • E). These power plants were selected because Plant-2 is equipped with two tilt arrangements. Furthermore, Bikaner is situated in a desert area where high solar irradiance is available with more than 300 days of clear sky. A Google Maps view of the test solar PV plants is described in Figure 3. A technical parameter comparison table of both the test plants including, the details of location, year of installation, plant size, design parameters of plants, transformer parameters, inverter parameters, and PV module parameters is detailed in Table 1.

Design Specifications of Plant-1 (Fixed Tilt Angle of 30 • ) Rated at 1 MW
The design specifications of the 1 MW (fixed tilt angle) grid-connected solar PV plant used for the proposed study are described below as follows: • PV module rating = 300 Wp, make: Canadian Solar.

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The configuration of the mounting structure is such that each table comprises 40 modules on a table and a string of 20 modules in series.

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The SCB (String Combiner Box) will have a maximum of 24 inputs with fuses to protect the system from earth faults. For this 1 MWp solar PV plant, having a total seven SCBs are needed.
• To carry power from the PV array to the SCB, a 4 mm2 copper cable is used. Between the SCB and the inverter, a 150 mm2 aluminum cable is used. • Inverter rating: 1000kW, Hitachi make, 1000 V system at 50 • C temperature. • Transformer rating: two winding, 1 MVA capacity, voltage ratio of 0.300/33 kV, and impedance is 5%.

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The high-tension (HT) yard with the transformer 0.300/33 kV includes a lightning arrester (LA) and other switchyard components constructed close to the inverter for the plant. • Switchyard: One set of 33 kV breakers, isolators, after the transformer in each plant. This arrangement will be very close to the transformer. The outdoor type, structuremounted CT, PT, and breaker with CR panel (outdoor) have been selected. Grounding mesh covers the entire switchyard, giving an earth resistance (ER) value of less than 5 ohms. An auxiliary power supply of 220 volt AC for a spring charge motor and space heater will be provided to the CR panel and the breaker through an auxiliary transformer of 5 KVA is provided.  The design specifications of the 2.5 MW (two seasonal tilt angles) grid-connected solar PV plant used for the study are described below as follows: • PV module rating: 300 Wp, Canadian Solar make.

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The configuration of the mounting structure is such that each A common power evacuation point at the plant end will be provided at the four-pole structure where metering is provided.

PVsyst Software Simulation Result
Plant location is required in the form of latitude, longitude, and altitude along with a time zone to load a project in PVsyst software [28,37]. So, by using the database, PVsyst first loads the location details and then fetches the Metronome data file that provides the environmental data like solar insolation, horizontal and different angles with different directions, temperature, and wind speed with average data of the past 20 years. Then, by using the project design, PVsyst can select the plant type and grid connected and later can freeze the orientation, plant size, module type and size, and inverter type and size. Additionally, PVsyst can fill in the different types of losses along with the shading of the plant. By simulation, one can get the final result file. After getting final results of two different reports of plants, a final comparison table was prepared. The sun path for Bikaner's location is shown in Figure 4a. Furthermore, a visual representation of the azimuth and tilt angle selection is illustrated in Figure 4b. As per convention of PVsyst software, "in northern hemisphere, the plane azimuth is defined as the angle between south and collector plane. This angle is taken as negative toward east, i.e., goes in the anti-trigonometric direction". For example, in the south plane, azimuth = 0, in the east plane, azimuth = −90 • . "In southern hemisphere, the plane azimuth is defined as the angle between north and collector plane. This angle is taken as negative toward east, i.e., goes in the trigonometric direction".

PVsyst Report for Plant-1 of 1 MW Rating at a Fixed Tilt Angle of 30 •
A PVsyst simulation study has been conducted with the consideration of the fixed tilt at 30 • with shadow on 21st December, which is the shortest day in the Northern Hemisphere with a 7.47 m pitch. The distance between row to row (first point of row to first point of next row distance, or midpoint of first row to midpoint of next row) is called the pitch. By simulation of Plant-1 with a 30 • fixed tilt orientation, the result is that it has the information of the results in table format that contains the monthly radiation and generation and also has the resultant performance ratio and per KW yearly generation values. It is illustrated in Figure 5 that Plant-1 has a 77.69% PR and 1630 kWh per kWp yearly generation. Simulated result data for Plant-1 using PVsyst are provided in Table 2. Furthermore, the loss diagram of Plant-1 is detailed in Figure 6. Loss of energy due to variations of PV in Plant-1's temperature compared to STC is observed to be equal to 9.6%.  The symbols used in Table 2 are described here, GlobHor: horizontal global irradiation, T Amb: ambient temperature, GlobInc: global incident in collector plane, GlobEff: effective global correction for IAM and shadings, Earray: effective energy at the output of the array, E_Grid: energy injected into grid, EffArrR: efficiency of array (Eout array/rough area), EffSysR: efficiency of system (Eout system/rough area).   Figure 7 that Plant-2 has a 77.90% PR and 1674 kWh per kWp yearly generation. The simulated result data for Plant-1 using PVsyst are provided in Table 3. Furthermore, a loss diagram of Plant-2 is detailed in Figure 8. Loss of energy due to variations in PV Plant-2's temperature compared to STC is observed to be equal to 9.8%.

PVsyst Report Final Result Comparison
To compare the PVsyst simulation results of the proposed test plants, a comparison is prepared with the help of a PVsyst report and loss diagram, detailed in Table 4. Analysis of the PVsyst simulation results, which are included in the comparison Table 4 is detailed below as follows: Both plants have the same polycrystalline PV module, so module conversion efficiency is the same in both plants and equal to 15.31%. Presently, industrial, easily available modules touch 17% efficiency. • PV loss due to irradiance level is a positive quantity which helps to increase the generation. In two seasonal plants, it is more than a fixed tilt angle plant. • PV loss due to temperature depends upon the air circulation (wind velocity) in freemounted solar plants and local temperature along with the PV module temperature coefficient factor [42]. So the combined result of all these factors is computed by PVsyst internal simulation.

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Module quality loss, LID (light-induced degradation), and module array mismatch loss depend on the selected module type. It is available in the. PAN file format, which is provided by the manufacturer.

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The ohmic wiring loss percentage is the same in both test plants and also has the same percentage DC ohmic loss. • Inverter loss during operation (efficiency) depends on the selected inverter type. It is available in the. OND file format which is also provided by the inverter manufacturer. • System unavailability loss in both plants considered is 0.7% and equal to a threeday grid outage. The three-day grid outage is considered because both plants have observed a threeday grid outage (  Table 5. Below, a detailed formula is used to compute per kWp generation peak data of plants. Per kWp unit generation = unit generation at that day(KWh) plant capacity (KWp) For a graphical comparison of both test plants on monthly tilt angle generation variation, a graph on unit/kWp level is prepared and depicted in Figure 9. From Figure 9, it is analyzed that the two seasonal Plant-2 gives more generation with the 13 • tilt angle in the month of summer from April to August, while in the remaining months, both plants give the same level of generation.

Emulation Result of Test Solar PV Plants
To emulate the impact of the tilt angle on real-world solar PV plants, the monthly generation of both proposed test plants is considered. To compare both test plants, the per kWp monthly generation for each month is shown in Table 6. The emulated impact of tilt angle is illustrated in Figure 10. It is established that by using two seasonal tilt angles, one can get more generation in the months of April, May, June, July, August, and September. In the month of March, both plants give maximum generation as compared to other months because in March, the PV module gets conditions near the STC (standard test condition), i.e., ambient temperature at nearly 25 • C and radiation of 1000 W/m 2 . The generation range comparison of the proposed test plants in terms of units per kW is illustrated in Table 7. A comparison of per unit kWp generation for different days by the fixed tilt and two seasonal tilt angle plants is shown in Figure 11. From the analysis of Figure 11, the results are concluded as below as follows:

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Both plants are off for three days. For ranges between four and five, Plant-1 generates more than is covered by Plant-2 in a range of more than five. Because of this excess generation range of more than five, Plant-2 gives more generation as compared to Plant-1.

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If more than four units per day per kWp are considered for a clear sky, then the Bikaner location has more than 290 days with a clear sky.  Here, impact of till angle on plant performance is highlighted. As per Sun-Earth Geometry, sun moving everyday East to West and seasonally moving from Tropic of cancer to Tropic of Capricorn, to get maximum optimized solar insolation, for fixed tilt and seasonal tilt PV plant, choose PV module direction toward South for Northern hemisphere and towards North in Southern hemisphere and tilt angle selected as per facing toward Tropic of Equator. In this optimized selection for MW size solar PV plant, to reduce the shadow loss pitch selection as per 9 AM to 3 PM Sun window on 21 DEC (in Northern Hemisphere) and 21 June (in Southern Hemisphere). Physically, as per techno commercial optimization, if tilt angle is high then there is a need to increase pitch to reduce row to row shadow loss. This will increase the land size, cable length and ohmic loss. So to optimize these parameters, there is need of optimized tilt angle and pitch.
As per design optimization, to optimize temperature loss there is a need to select proper tilt angle and air circulation because of PV cell designed for STC condition (Solar insolation 1000 W/m 2 , AM 1.5 and temperature 25 • C). If solar insolation increases, PV cell converts solar energy to electrical energy as per cell efficiency. Energy which is not transformed to electrical energy will either increases the temperature of cell or it will be transmitted from the PV cell. This rise in temperature reduces the cell efficiency. This temperature variation is observed from sunrise to sun set and season to season. To calculate temperature loss, the PVsyst software simulation is used. For low plant tilt angle dust deposition is high which increases the temperature of PV cell and also increases the soiling loss. So there is need of selection of more than 10 • slope to reduce dust deposition with the help of gravitation.

Performance or Yield Assessment of Solar PV Plant Results on the Test Day
To investigate the daily performance, or yield assessment, of a solar PV plant, solar insolation and inverter generation data are used to calculate PR and CUF. The test was performed on the day of 17th of October 2018. In the month of October (winter season), both test plants were at a 30 • tilt angle. The solar insolation data was extracted from a pyranometer situated at the test plant's location and measured. The solar insolation graphical representation is shown in Figure 12 where the x-axis indicates time and the y-axis indicates the pyranometer reading (in W/m 2 ). To investigate the daily PR, the primary need for cumulative inclined solar insolation and the energy output of that day, the energy outputs of the test day were extracted from the SCADA and, to find out the cumulative inclined solar insolation, the area under the curve was calculated as shown in Figure 12. To get optimal results, use the trapezoidal rule. A typical trapezium is shown in Figure 13. To calculate the PR of a solar PV plant on test day, the formula used was as follows and results are shown in Table 8: To calculate the daily CUF on test day, the following formula was used and the results of both test plants are shown in Table 8: The performance of the solar PV plant on the test day 17 October 2018, followed the results from Table 8

Impact of Tilt Angle on Yearly Plant Performance
A combined visualization of monthly unit/kWp simulated and actual generation has been carried out, considering the methodologies detailed in [43][44][45][46][47] and illustrated in Figure 14. It can be easily visualized that in the summer months, the two seasonal Plant-2 performs better as compared to the fixed tilt plant in both simulation and actual, and it satisfies the design of PV plants on an annual basis. The following are the observations from the graphs of Figure   To check the impact of tilt on yearly plant performance, all PVsyst simulated and emulated data are collected in Table 9. Finally, the concluded results from Table 10 are  as follows: 1.
The global horizontal insolation computed from the PVsyst's simulated output is the same for both the fixed and two seasonal tilt plants, as both are in the same location.

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As compared to Plant-1, which has a fixed tilt angle of 30 • , Plant-2 has more enhancements in solar insolation due to two seasonal tilt angles.

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Plant-2 has more PR as compared to Plant-1 because Plant-2 has lower shading loss in the summer season, along with lower inverter efficiency loss.

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Plant-2 has 2.70% more units per kWp generation compared to Plant-1 because of more input fuel (solar insolation).

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Plant-1 and Plant-2 both give lower values as compared to PVsyst's simulated value. So, in year 2018, after consideration of degradation, Plant-2 also has more generation targets as compared to Plant-1. 8.
Plant-2 has only 1.42% more generation as compared to Plant-1. The reason behind it is as detailed below.
• Plant-1 has low degradation or damage because of the lack of any effect or mechanical damage during the tilt angle change procedure. Plant-1 gives 0.71% more generation as compared to the three-year PVsyst generation target. • However, Plant-2 gives 0.51% low generation as compared to after three years PVsyst generation target. Because during the tilt angle change process period, due to improper handling, some modules may get some minor cracks.

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Plant-2 gives 0.26% more CUF (18.61%) as compared to Plant-1 (18.35%), because of the two seasonal tilt angles, which means with an increasing number of tilt angles, CUF may increase. If CUF increases, then the cost of solar power reduces. 10. Losses (in terms of percentage) for Plants-1 and 2 computed using the PVsyst software and recorded on the real-time power plants installed at Bikaner, India are provided in Table 10. It is observed that losses computed using the PVsyst software are comparable with the real-time losses recorded on the power plants.

Performance Comparative Study
The performance of the proposed fixed tilt angle (Plant-1) and two seasonal tilt angles (Plant-2) is compared with the methods reported in [48] in terms of PR and CUF and provided in Table 11. In [48], the authors presented the analysis of the 2.5 kW PV system installed in Algeria by collecting the data from the field, and the analysis was carried out by simple statistical methods. In [49], the authors presented a study for the analysis of the performance of a grid-connected solar photovoltaic (PV) system installed on the terrace of a building in Algiers. A database of radiometric and electrical data was prepared, and the performance was evaluated by simple statistical analysis of the data set. In [50], the authors presented a study for the performance assessment of two photovoltaic arrays made of different silicon photovoltaic technologies. An empirical analysis of meteorological and electrical parameters was conducted, and mathematical models of efficiency in relation to module temperature were determined. It is observed from Table 9 that the accuracy of the performance evaluation of the solar PV data has improved using the proposed method of study with the help of the PVsyst software. Furthermore, the CUF has improved by the use of two seasonal tile angles. In Table 11, higher values of PR and CUF for the Plant-1 and Plant-2 are obtained for the following reasons:

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The cleaning of the plants is performed as per the specified time cycle. Delays in cleaning time are eliminated.

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Maintenance of all equipment in the plants is performed as per specified schedules.

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The tilt angles of Plant-2 changed as per the time cycle specified in the specifications. • Fault frequency is reduced by preventive maintenance.

Conclusions
This paper presents a detailed study of the solar PV plant. The performance of the MWcapacity grid-connected solar PV plant is evaluated using a PVsyst software simulation, and then compared it with actual plant units considering per kWp generation on an annual basis. This is concluded that in the practical environment, two seasonal PV plant give 1.4% more energy generation and 0.26% more CUF, as compared to a fixed tilt angle plant at location on 28 • latitude nearly above the Tropic of Cancer, in the Indian desert climate. A fixed tilt angle plant can generate energy more than 1600 units per kWp easily. Maximum energy generation is observed in the month of March, and both test plants show good performance ratios in the range between 76% and 77%, nearly close enough to the PVsyst simulated PR after a degradation for a period of three years, along with a good range of CUF between 18% and 19% as per the Indian climate. The efficacy of the proposed approach is better compared to the statistical approaches reported in the literature. Data Availability Statement: All data generated or analyzed during this study are included in this published article.

Conflicts of Interest:
The authors declare no conflict of interest.