PVsyst software is one of the most widely used simulation tools in the design and calculation of basic considerations of photovoltaic systems PVSyst (2021). Modeling in PVsyst starts with system sizing, which comprises desired power rating or available area, PV module, and inverter sizing. Based on the given input specifications, the PVsyst will propose module configurations for further simulation study. This software updates weather details of the selected location, which helps in evaluating output parameters. PVsyst tool gives monthly global irradiance, diffuse irradiance, temperature, and wind speed of the selected location. Based on these data, the trajectory of the Sun, which provides information on losses that occur during period of a year, is also given. The results of the simulation tool include total energy produced, performance ratio, and specific energy. By utilizing these results, energy yield, capacity factor, and efficiency of PV array and PV system can be calculated. The existing PV system behavior and further expansion of the system can be carried out Photovoltaic Software (2021).

It is the energy generated by a photovoltaic array. Array energy mainly depends on the area of the total array of the PV system [A_A], solar radiation [I_s] incident on PV modules, and the efficiency of the PV module [ η P V ] , how successfully it transforms solar energy into electrical energy. The area of the total array [A_A] of the PV system is calculated by considering the total number of PV modules multiplied by the area of individual modules. The extra space to accommodate the panels in specified orientation and between the strings is also added. The area used by the total arrays of the installed PV system is 12,000 m². Therefore, the array energy is expressed as a product of all the mentioned three parameters, as shown in the following equation: E A E = A A × I s   × η p v , k W h . (1)

A solar array is a group of solar modules joined in series and parallel. Hence the net array energy output mainly depends on the area of the total arrays of the PV system, the efficiency of the PV module for the incident solar irradiation, and the full capacity of the solar PV plant. It is also expressed as the ratio of energy array to the entire plant capacity (PC), as shown in the following equation: D E A = E A E P C , k W h . (2)

Any system’s efficiency is determined by the input it receives and the output it produces. The efficiency of an array is determined by the input, which is the solar irradiation dispersed across the entire array, and the generated output energy as expressed in the following equation: η A = E A E A A × I S × 100. (3)

The existing plant is an integrated grid system, the energy generated by the PV arrays is converted to AC and pumped into the grid via inverters. Solar energy generation depends on solar irradiation, and energy conversion depends on the inverter’s performance and losses. Hence the grid energy is expressed in Eq. 4 as a product of array energy [ E A E ] , the efficiency of the inverter [ η i n v ] , and loss efficiency [ η L O S S ] . E G E = E A E × η i n v × η L O S S , k W h . (4)

It is the solar PV system’s net energy output, expressed as a ratio of energy injected into the grid to the capacity of the solar PV plant, as shown in the following equation: D E G = E G E P C , k W h / k W p . (5)

A solar System’s efficiency is commonly defined as the ratio of solar energy input to electrical energy output. The system efficiency depends on many parameters, whereas here, it is declared as the ratio of grid energy [E_GE] to the solar irradiation [I_s] and the area of total PV arrays [A_A]. η s y s = E G E A A × I S × 100. (6)

The capacity factor can be defined as the actual electricity production divided by a power plant’s maximum feasible electrical output over some time, as shown in the following equation: F c = D E G O H × 100. (7)

The performance ratio (PR) is a frequently used term for assessing the relative performance of solar panels with different designs, technologies, capacities, and locations. PR is calculated using Eq. 8, where it is expressed as a percentage ratio of net grid energy output [ D_EG] to the reference energy yield [Y_R]. P R = D E G Y R × 100. (8)

Loss and degradation rate are the two essential parameters for analyzing the performance of PV systems. In a survey conducted by the National Centre for PV Research and Education at the Indian Institute of Technology, Bombay, and National Institute of Solar Energy, Haryana, it is assumed that the deterioration in crystalline silicon modules would vary from −0.6 to −5%/year (Dubey et al., 2016; Dubey et al., 2017). The mathematical equation for degradation rate can be expressed as (Kumar et al., 2019) % D R = 12 ∗ m c × 100 , (9) where m: slope and c: intercept. These values are considered for the present study directly from the literature (Kumar N. M. et al., 2019).

The solar irradiation and ambient air temperature of the study location from January 2020 to December 2020 are shown in Figure 1. Monthly solar irradiation and ambient temperature are obtained for analysis from the PVsyst simulation software tool. The annual average horizontal global solar irradiation is observed as 153.91 kWh/m². The maximum Sun irradiation of 190 kWh/m² is recorded in April, and the lowest in December, with 137 kWh/m². The maximum ambient temperature is in May at 30.7°C and the minimum in December at 24.6°C.

Figure 2A presents the estimated energy yields and energy given to the grid of the PV system. The total amount of energy generated from the PV system is 1780.878 MWh. The PV system yield ranges between 118.537 MWh in July and 178.499 MWh in March. Each year, the total quantity of AC energy put into the grid is about 1684.881 MWh. In July, the AC energy output was 118.537 MWh, while in March, it was 169.306 MWh. It is observed that the difference between DC and AC energy yields is caused by energy loss. This energy loss is due to module temperatures and various system constituents (Sharma and Goel, 2017). The PV system’s average efficiency in each month is estimated and shown in Figure 2A for extensive examination of PV system performance. The average annual efficiency of the total system is 16.3%, whereas the array efficiency varies between 16.24% (July) to 16.48% (May). In Figure 2B, the variation of specific energy over 1 year is presented. The total yearly electricity yielded from the PV system was 1774 kWh/kWp. The least and maximum possible monthly definite energy predicted are 125 kWh/kWp in July and 178 kWh/kWp in March, respectively. The total yearly energy at grid end is 1679 kWh/kWp, with a minimum monthly specific energy of 118 kWh/kWp predicted in July and a maximum of 169 kWh/kWp in March. The total annual energy delivered into the grid is estimated to be around 1684.881 MWh, with a minimum of 3,823 kWh anticipated in July and a maximum of 5,617 kWh during April. The average amount of energy injected every hour into the grid is forecasted to be 159 kWh in July and 234 kWh in April, which are presented in Figure 2C.

The two key performance indicators of the PV system are capacity factor and performance ratio. The yearly average capacity factor was 11.3%, with the least forecasted value of 9% in August and a peak forecasted value of 14% in March. The average annual performance ratio was 87.96%, with the least indicated with a value of 86.51% in July and peak forecasted with 88.79% in May. Figure 3 displays the F_c and PR of the PV plant. Even though the capacity utilization factor and performance ratio both depends on the energy yield of the solar PV system, there are other individual parameters that each of them depends on. Capacity factor also depends on the operating time of the PV plant, whereas performance ratio is proportional to reference energy yield, which makes the difference in their final values.

In this section, the energy losses are evaluated in a 1 MW roof-top connected PV system over 12 months using a PV system modeling technique and are presented in Figure 4. The energy loss varies from -0.7% (−12900.311 kWh) to −9.7% (−204877.98 kWh). The minimum foreseen worth is because of auxiliaries (−0.6%), system inaccessibility (−0.7%), and from the side of the electrical converter, there are losses in the AC resistance unit (0.7%). The temperature was the source of the greatest anticipated energy loss (9.7%). Nonetheless, the loss in energy due to solar irradiance levels on the PV module (3.9%), module quality loss (−3.1%), and light-induced deterioration are all significant (2.6%), and also the electrical converter operational loss (−2.3%) is additionally limiting the effectiveness of the PV system. The total energy losses are estimated as 715.76 MWh, with a total energy loss of 34.9%.

The loss in the performance of the solar modules due to exposure to sunlight is named light-induced degradation (LID). Accurate measurement of power loss over time is marked as degradation rate (DR), where these two parameters play as vital performance indicators of a PV system. The observations show a LID of -2.7%, which accounts for the energy loss value of −49,588.921 kWh/year for the PV system. Estimated energy loss because of the degradation rate within 1 MW crystalline PV plant ranges from −10,689.3 to −89,099.5 kWh/year, respectively.

The forecasted parameter in this study is equated with different PV systems based on the given performance information in their literature. The findings of this investigation appear to be consistent with those of previous studies, as shown in Table 1. This study helps the investors and researchers function of PV plants in the coastal areas.