PLANNING STUDY OF HYBRID POWER PLANT SOLAR PV-DIESEL GENERATOR ON KODINGARE ISLAND, SINJAI REGENCY

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Introduction
As the world's largest country, consisting of around 17,500 islands with a population of about 220 million people, Indonesia has significant challenges in meeting its electrical energy needs [1].Currently, most electricity sources in Indonesia still depend on fossil fuels, with more than 82% of electricity produced from this source, while 18% comes from renewable energy.Even though the potential for solar energy in Indonesia reaches 207,898 MW, its utilization is still very low, around 0.04% [2].Amid this context, Kodingare Island faces the problem of electrical energy supply provided by diesel, which can only operate for seven hours.Before being supplied with diesel, Kodingare Island had a solar power plant with a capacity of 11.72 kW [3].This PLTS can only operate for less than a year due to high voltage caused by lightning and lack of adequate maintenance.
Research evaluating the optimal solar panel and battery configuration for a 4 kW power plant in Lubumbashi, DR Congo, found that the PV system was able to produce an energy surplus of 38% [4].The system is designed with PV-Diesel with 70% Renewable Penetration and 18 hours of autonomy as a more economical alternative to increase electrification in Indonesia with lower investment costs [5].Research that highlights the management of redundant energy in PV-Battery-Diesel systems in Palestine, resulting in efficient reduction of electricity costs [6], as well as research that explores the application of renewable energy to replace diesel generators on remote islands of the Indian Ocean, with the result that renewable energy contributes by 29.2%, reducing electricity costs and demonstrating the feasibility of the technology for areas that do not yet have access to electricity in Indonesia [7].
Therefore, this research will focus on modeling and simulation using HOMER Pro software to evaluate the potential and performance of the hybrid power system on Kodingare Island [8].Apart from that, economic aspects and planning feasibility will also be essential aspects in optimizing this system.Thus, this research aims to produce a design that includes technical, financial, and feasibility aspects to overcome energy challenges on Kodingare Island by considering several advantages not available in previous research, such as three-dimensional PV layout planning and higher renewable penetration contribution.

Economic Analysis a. Initial Investment
The initial investment costs for a hybrid power system on Kodingare Island include general costs for all components and mechanical and electrical work costs [9].

b. Maintenance and operational costs (O&M)
Operating costs include day-to-day expenses such as fuel and labor.Meanwhile, maintenance costs include expenses to maintain optimal condition and performance through inspection, repair, and replacement of worn or damaged components, calculated using the following equation [10]: where: M = cost O&M (IDR).

c. Life cycle cost (LCC)
The concept of calculating total costs from start to maintenance of the project.It includes all costs, such as initial investment, operations, maintenance, and replacement, calculated using the following equation [11]: (2) LCC using the following equation [11]: where: LCC = life cycle cost (IDR) Ct = initial investment + component replacement costs (IDR) AW = present value costs for total maintenance and operational costs for n years of project life (IDR) i = interest rate (%)

d. Cost of Energy (COE)
Total energy costs are determined by LCC, capital recovery factor, and total annual energy load, calculated using the following equation [11]: COE for PV was calculated using the following equation [11]: The time required for the investment that has been issued to be returned to investors.The smaller the PBP value, the better; the risk factor for the return on capital will be faster in a short time, calculated using the following equation [12]:

b. Net Present Value (NPV)
NPV was used for comparison between the market value of an investment and the cost itself.If the NPV value is negative, the project is not recommended for implementation; if the value is positive, then the project is feasible to implement.The NPV value is zero, meaning there is no difference if the project is still implemented or rejected, calculated using the following equation.[13]:  be said to be feasible if PI must be greater than 1 because 1 is the break-even point between the investment value and profits, calculated using the following equation [10]: where: NCFt = net cash flow for the period from year 1 to year n (IDR) n = investment age (year) II = cost initial investment (IDR) i = interest rate (%)

d. Internal Rate of Return (IRR)
The discount rate that makes the present value of all expected revenues equal the present value of all costs involved in the project.The higher the IRR value, the more profitable the project is, and projects that have an IRR greater than the discount rate used are considered feasible to run, calculated using the following equation [13]: Where: NPVr = net present value with low interest rates (IDR) NPVt = net present value with high interest rates (IDR) ir = low interest rates (%) it = high interest rates (%)

Research Stages
The research begins with selecting a research area based on the problems studied in the introduction.The following process is to conduct a simulation using HOMER software to produce technical aspects of energy production to compare the power contribution of each diesel, fuel consumption, excess electricity, and renewable energy penetration.
Economic and feasibility aspects are carried out using numerical calculations with financial analysis methods with input from HOMER software output.Economic elements include initial investment costs, O&M costs, LCC, and COE.However, researchers must determine the investment costs for designing the hybrid power plant to get these results.
The feasibility aspect of this research is the design performance evaluation aspect.Several standards in this planning are based on the economic price per kWh, PBP with a period shorter than the useful life, positive NPV, IRR more significant than the credit interest rate, and PI more significant than one, where the final stage of this research is designing the layout placement using SketchUp Pro software.

Electical Energy Load Profile
The first step in this design is to determine the total daily load used.The daily load on Kodingare Island is the electrical energy consumption load consisting of household loads, mosque, school, healthcare, and public toilets can be seen in Table 1.

Technical Analysis of HOMER Pro Software Simulation a. Total Electrical Energy Generated
The total energy generated from the Hybrid Power Plant system can be seen in Figure 1 below.
It can be seen that AC load consumption is 33,580 kWh/year, where electricity production from solar panels reaches 32,981 Wh/year or 89.1%, solar is 4,048 Wh/year or 10.9% of the total output and excess electricity is 931 kWh/year and the renewable fraction was 87.9% greater than previous research [5].

b. Fuel Consumption
Figure 2 shows data in the form of the amount of fuel consumption used in supplying electrical power to the load of 5.71 L/day and 2,086 L/year with the energy generated of 4,048 Wh/year.The detailed data obtained regarding fuel consumption can be seen in Figure 2.

Hybrid Power Plant System Design
This hybrid power generation system uses three sets of solar panels, each arranged in four series and three parallel, where each set of panels has a capacity of 5,640 Wp, which is connected to an inverter, each with a total of 8 kW.This Hybrid Power Generation System uses 48 batteries arranged in series, 24 with 2 in parallel, and one diesel power with a capacity of 30 kW.Equipped with a DC and AC protection system and an ATS as a switch from the generating source.
The wiring diagram for this Hybrid Power Plant system can be seen in Figure 3.

Economic Analysis a. Initial Investment Cost
All costs incurred for the construction of the Hybrid Power Plant system as shown in table 2.

b. Operational and Maintenance Cost
The total costs incurred for O&M costs of a hybrid power plant include the purchase of generating fuel costs and a cost of 2% of the total initial investment costs, where the calculation of O&M costs can be seen as the calculation below.
Operational costs can be calculated based on fuel consumption worth 6.800/Liter IDR [14]

c. Lyfe Cycle Cost
The plan is that this Hybrid Power Plant can operate for 25 years based on the age of the solar panels.The interest rate used is 8.43% [15], and the operating cost is 14.184.800IDR, which can be calculated using the following equation:

d. Cost of Energy
The Capital Recovery Factor (CRF) to convert all life cycle cost cash flows into a series of annualized costs is calculated using the following equation:

b. Net Present Value
The NPV value is calculated by looking at the total net income to get the NPV value of a system, then the future value or total net income is compared to the value of the present value of the system or the initial investment of the plant.The NPV value can be obtained based on the following equation.
Table 3 shows that the total present value of the net cash flow as a result of multiplying the net cash flow by the discount factor is 268.160.151IDR; if the initial investment is 258,290,000 IDR, then the NPV can be calculated as follows:

c. Internal Rate of Return
To determine the IRR value when NPV = 0, the interpolation method is used between interest rates that produce positive NPV and interest rates that pay negative NPV, where the low interest rate used is 7%, and the high interest rate is 9%.The NPV value with a low-interest rate can be obtained based on the equation below.
From the table above, the data as shown in Table 4 below is then calculated using the following equation: ) (9% -7%) = 8.90% Obtaining an IRR value of 8.90%, higher than the credit interest rate of 8.43%, which is why the Hybrid Power Plant plan is considered feasible on Kodingare Island.

d. Profitability Index
With a total net cash flow present value of 268.160.151IDR and an initial investment cost of 258,290,000 IDR, the PI value can be calculated as follows: cash flow for the period from year 1 to year n (IDR) n = investment age (year) II = cost initial investment (IDR) i = interest rate (%) c.Profitability Index (PI) PI was used for showing the profits obtained from a project within the life of the project; investment can Copyright © 2023.Owned by Author(s).This is an open-access article under CC BY-SA License.
Based on the calculation of LCC, CRF, and total annual energy for a load of 33,580 Wh, it is possible to determine the COE with the following calculation:  =      = 467,109,744  0.0972 33,580 160.151 -258.290.000= 9.870.151IDR ,376−(−2,412,194 ) and fuel consumption of 2.086 Liters with the following calculations:

Table . 2
. Initial Investment Based on the calculation of LCC, CRF, and annual kWh above, the COE value is obtained with the following calculation: Table. 3. Net Present Value