Journal of Technology and Policy in Energy and Electric Power Volume 1.
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December 2024 https://doi.
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33322/jtpeep.
v1i1/101 Research Article Auxiliary kWh Efficiency of Substations Using Renewable Energy Potency in East Kalimantan Province Chandra Lima Silalahi1*.
Ananda Priatama1.
Saut Parsaoran S1.
Setyaningsih Nugrohowidi1.
Bambang Priyono1 1 Universitas Indonesia *Corresponding author: Chandra Lima Silalahi, feliciasilalahi3110@gmail.
CITATION
Author Name.
Article title.
Journal of Technology and Policy in Energy and Electric Power.
1:1.
https://doi.
org/10.
33322/jtpeep.
ARTICLE INFO
Received December 10, 2024
Accepted December 22, 2024
Available online December 30 2024
COPYRIGHT
Copyright A 2024 by author.
Journal of Technology and Policy in Energy and Electric Power is published by PLN PUSLITBANG Publisher.
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This work is licensed under the Creative Commons Attribution (CC BY) license.
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Abstract: PT PLN (Perser.
as the Indonesian state electricity supply company must carry out an energy transition in terms of generation, transmission and distribution.
Substations in Indone- siaAos electric power transmission sector have not yet incorporated the idea of green energy into their operations, despite the fact that there is a great deal of potential for green energy in substations, such as the usage of solar and wind energy.
The primary power source for the auxiliary substation is energy form the grid, with diesel power serving as a backup.
However, the energy mix in the Kalimantan grid is still dominated by energy from coal .
ased on the Laporan Evaluasi Operasi Tahunan PLN UIP3B This research investigates the technical and economic viability of utilizing renewable energy in auxiliary substations to mitigate the companyAos escalating financial burden.
Technically, the study aims to determine the optimal PV panel capacity required for auxiliary power Economically, it evaluates the total investment and operational costs.
Internal Rate of Return (IRR).
Return on Investment (ROI), payback periods, and Levelized Cost of Energy (LCOE).
Unique to this study is the direct measurement of kWh consumption data from 23 substations in East and North Kalimantan, a method not previously The findings provide recommendations on the appropriate PV capacity for installation in substations and present economic Keywords: substation, energy transition, techno-economy analysis Introduction Paris Agreement plays a crucial role in addressing the impacts of climate change by limiting the temperature increase to 5AC by 2060.
As a country that has ratified the Paris Agreement.
Indonesia is committed to reducing greenhouse gas emissions by 29% through domestic efforts and up to 41% with international support by 2030.
In 2025 and 2028, the electricity sector is targeted to have an EBT mix of 23% and 28%, respectively, which will then become a reference for the Electricity Supply Business Plan (ESBP) .
As of August 2020.
IndonesiaAos renewable energy potential 8 GW, six times higher than its current power generation capacity of 69.
6 GW .
According to Presidential Regulation No.
22/2017 on the National Energy Plan, the potential capacity of solar power plants in Indonesia is 207,898 MW .
Indonesia, the average solar energy received on horizontal Journal of Technology and Policy in Energy and Electric Power Volume 1.
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v1i1/101 surfaces ranges from 4.
73 to 5.
77 kWh per square meter per day, with an average of 11.
8 to 12.
hours of daylight per day.
However, the share of solar capacity in IndonesiaAos energy production is still very low, at only 3 MW in 2002, 90 MW in 2018, and a further 152 MW in 2019 .
This highlights the need to accelerate the adoption of renewable energy technologies such as solar photovoltaic (PV) to reduce dependence on conventional energy sources that contribute to carbon The role of Perusahaan Listrik Negara (PLN), as the largest electricity provider in Indonesia, is key to accelerating the energy transition towards net zero emissions.
To address the slow expansion of solar energy in the residential, commercial, and industrial sectors, the Indonesian government, under the Ministry of Energy and Mineral Resources (MEMR), has implemented several regulations that provide a legal structure and metering agreements for PV system users in the country.
In 2013.
PLN implemented a regulation known as PLN Regulation 0733.
K/DIR/2013,
which allows the installation and operation of photovoltaic (PV) systems alongside the national However, within the electricity transmission system, substations have yet to incorporate the concept of AogreenAo into their operations.
Although there is significant potential in substations, such as the use of rooftop solar PV.
Substations require low-voltage power for their auxiliary loads, which include lighting.
HVAC, transformer cooling fans, and battery charging.
Most of these require a guaranteed, uninterrupted supply .
Self-discharging transformers, or substation auxiliaries, typically draw power from the grid to supply additional loads at substations.
Based on the Annual Operation Evaluation (AOE) of the Electric Power System at PT PLN (Perser.
Unit Induk P3B Kalimantan, it is reported that the energy mix in the Kalimantan grid is still dominated by coal at 70Ae80%.
The total energy consumption of self-consumption transformers at substations is constantly increasing, from 3,092,350 kWh in 2021 to 3,285,410 kWh in 2023.
This data shows that the use of power transformers as the main source to meet additional loads at the substation will incur relatively high costs, which will ultimately become a burden on the company.
The purpose of this study is to provide a technical and economic analysis of the potential use of renewable energy in substations to supply additional loads through PS transformers or substation auxiliaries, so that it is cost-effective and can reduce the burden on the company in the future.
The levelized cost of electricity from solar PV technology on the grid is lower than that of coal technology .
This study focuses exclusively on a hybrid system consisting of solar panels (PV), an inverter, and a grid.
From an economic point of view, kWh consumption data will be used, which will be multiplied by the cost of production (COP) to obtain the companyAos expenditure.
Figure 1.
Research Method Per year for the auxiliary substation, so that data in the form of IRR.
ROI payback periods, and LCOE will be obtained from the simulation results.
Journal of Technology and Policy in Energy and Electric Power Volume 1.
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v1i1/101 Materials and methods This research will discuss how to present the existing green energy sources in 23 substations spread over the provinces of East Kalimantan and North Kalimantan (Fig.
The study will focus on two aspects: technical and economic.
Based on (Fig.
the author applies several steps to the research stages as follows:
Asessment of Renewable Energy Potential In this stage, an assessment of renewable energy potential in the East Kalimantan and North Kalimantan regions is carried out.
The renewable energy potential in the substation is solar energy and wind energy.
The solar energy potential based on ESMAP (Energy Sector Management Assistance Progra.
has an average global horizontal irradiation (GHI) of 4.
4 kWh/m2 in this region .
For wind energy, however, the potential in East Kalimantan and North Kali-Ex is relatively small, with an average wind speed of 2.
m/s at a height of 10 meters .
Based on this, the renewable energy used in this study is solar energy by utilizing the substation roof.
Collecting Data From Conventional Substation At this stage of the research, the authors collected primary data on the energy consumption of auxiliary substations per half hour in 23 substations in East and North Kalimantan.
The list of substations and coordinate points in this study is shown in Table These electrical energy consumption data are multiplied by the average production cost price to obtain the amount of cost incurred by the company for kWh of auxiliary In addition, the coordinate data of the substation is used to see the potential of solar energy at each point.
Therefore, one of the advantages of this research is that it examines technical and economic studies with primary data measurements from real auxiliary substation loads.
Several studies have carried out similar research in this area.
According to Mohamed Dib et al.
, the combination of PV systems with existing systems in transmission substations can improve the quality of the energy supplied and reduce losses, but they have not provided further technical-economic studies before generalizing this solution .
As stated by Washington de Araujo Silva Junior et al.
, auxiliary systems (SAu.
in transmission substations require a continuous power supply.
In the event of an external power supply becoming unavailable, the system is reliant on diesel emergency generators (DEG), which have slow response times and are susceptible to failure.
The experimental results demonstrate that the battery energy storage system in a pho- tovoltaic configuration is capable of operating autonomously and maintaining a stable voltage and frequency without ex- periencing outages.
The system is capable of withstanding sudden changes in active power and recharging the BESS with excess energy from the PV This solution ensures a reliable and continuous energy supply for auxiliary systems in the substation.
Nevertheless, further studies are necessary to determine the optimal size and technical and economic viability of this solution .
Al Ashwal suggests that additional research is necessary to enhance the design of photovoltaic (PV) systems and assess their effectiveness in various operational scenarios.
Future research should prioritize conducting a thorough technical- economic study and developing techniques for effectively integrating photovoltaic (PV) plants into a broader power grid.
Journal of Technology and Policy in Energy and Electric Power Volume 1.
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v1i1/101 As proposed by Bogdan Filip and Marian Dragomir, this study recommends further investigation to assess the efficacy of solar plants in diverse operational and geographical contexts .
As posited by Mpai Letebele and John Van Coller, future studies ought to prioritize a more comprehensive technical and economic analysis alongside the development of more effica- cious energy management strategies.
This will enhance the reliability and efficiency of auxiliary systems in transmission substations .
Consequently, the research will investigate the techno- economic analysis of photovoltaic use in 23 East Kalimantan substations, utilizing geographic data and varying load data for each substation.
Use of PV Syst Software for Design PV System In this research, the PV System application is used to perform the engineering design to determine the amount of PV that can be installed based on the load requirements at 23 substations.
In general, the steps used in the PV-Syst simulation used in this study are as follows:
A Create a new project based on the location point.
A Input the location based on Table I to obtain the meteo file.
These data are environmental data in the form of global horizontal irradiance (GHI), temperature, and others in the PV System application database.
A Determine the orientation of the solar panel to be in- stalled.
In this research, it was determined that the plane tilt is 5Aand the azimuth is 0A.
A Enter the technical design parameters of the rooftop PV system to be installed.
At this stage, the first thing to be done is to determine the capacity based on the installed substation auxiliary load data.
The author uses a capacity of 1.
5 times the maximum load of each substation.
The basis of this determination is to meet the Table 1.
LIST OF SUBSTATION AND COORDINATE LOCATION
No.
Substation Coordinate Location Maloy 9240714292072126, 117.
Sangatta 4721112155937056, 117.
Teluk Pandan 16344728965001734, 117.
Muara Badak 31026437358867215, 117.
New Samarinda 4068215823989753, 117.
Sambutan 5251231713622516, 117.
Kota Bangun 2710961612463912, 116.
Bukit Biru 4558801771471668, 116.
Embalut 38186850147653895, 117.
Tengkawang 5025235583121095, 117.
Harapan Baru 5473087315642758, 117.
Bukuan 5832135473056099, 117.
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v1i1/101 Karang Joang 1487511554770797, 116.
Manggar Sari 238087244158529, 116.
New Balikpapan 2258610566286643, 116.
Industri 2618428063952936, 116.
Kariangau 1654650291917648, 116.
Petung 3408153464332517, 116.
Longikis 516298671050907, 116.
Kuaro 803434711228812, 116.
Grogot 8985684107644853, 116.
Komam 8274758357930712, 115.
Tanjung Selor 810425134405983, 117.
Figure 2.
Research Location load requirements by providing a 50% reserve.
The PV system designed in this study is a rooftop PV system using the roof of the substation building (Fig.
Once the capacity has been determined, the type of panel and inverter to be used in the study will be determined.
A Determine the economic parameters.
The economic pa- rameters that will be included in the PV system appli- cation include module price, module support, inverter, wiring, combiner box, monitoring display system, me- tering system, installation service price, project lifetime, inflation rate, and electricity tariff (IDR 1500/kW.
A Carry out a techno-economic simulation.
This stage is the last stage of the PV Syst application, where the output results of calculations using the PV Syst application will be explained in the result section of this paper.
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v1i1/101 Figure 3.
Planning Design PV Rooftop for Subtation Usage Saving Cost Analysis This stage will determine whether or not the installation of a PV rooftop at the substation is feasible based on economic aspects.
The economic parameters that will be the basis are the levelized cost of electricity (LCOE), payback period .
n units of year.
, internal rate of return (IRR), and return on investment from the installation of PV rooftops in 23 Results and discussion According to the research that has been carried out, some points that can be the basis of recommendations for the installation of PV for the needs of auxiliary substations are as follows:
A stable substation load profile during the day is suitable for rooftop PV installation.
In terms of operation, the substation is in operation 24 hours a day.
The main load supplied by the auxiliary substation is in the form of air conditioning (AC) for temperature maintenance of equipment such as relays and bay control units (BCU), lighting .
, and supply of auxiliary motor drives.
Substation auxiliary needs vary, but at least in the East Kalimantan region, based on the years 2022Ae2023, a minimum of 72,000 kilowatt hours .
per year per substation is required.
Using the minimum average calculation, from a total of 23 substations, the auxiliary demand at the substation amounted to 1.
8 megawatt hours (MW.
per year.
In addition, the load profile at the substation is quite high.
This indicates that the auxiliary consumption pattern of the substation is fairly constant throughout the day.
Based on the sample at the Muara Badak substation, the load factor in December was 0.
A constant load, especially during the day, can reduce the impact of electrical instability due to the rise and fall of electrical Journal of Technology and Policy in Energy and Electric Power Volume 1.
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v1i1/101 Figure 4.
Planning Design PV Rooftop for Subtation Usage Results of the Technical Design Analysis In this study, technical recommendations were obtained for the technical PV rooftop capacity that can be installed in 23 substations.
The highest capacity is installed in the Embalut substation.
This is because the Embalut substation has the highest load compared to the other substations .
kWh at peak loa.
The total rooftop PV capacity required in the 23 substations is 642 kWp.
This PV capacity is defined in the general parameters of the PV System program (Fig.
and in the design output of the single line diagram output from the PV System program (Fig.
The configuration design required in this study can be drawn in the PV Syst application.
For example, based on (Fig.
, (Fig.
and (Fig.
, the rooftop PV configuration design at the Manggar Sari Substation uses 18 Jinkosolar brand PV panels with a capacity of 610 Wp connected into 2 strings, where each string is assembled in a series of 9 pieces.
The two strings are connected to each Huawei inverter, which has a capacity of 5.
0 kW.
The total area required is 50 m2, with the average substation roof having a minimum area of Journal of Technology and Policy in Energy and Electric Power Volume 1.
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v1i1/101 300 m2.
Based on the design, the total PV DC power is 11.
0 kWp, while the total PV AC power is 10.
0 kWAC, with a Pnom ratio of 1.
Table 2.
RESULT OF TECHNICAL ANALYSIS
No.
Substation Capacity PV .
Energy (MWh/yea.
LCOE
IDR/kWh Maloy
21,96
790,92
Sangatta
27,45
774,95
Teluk Pandan
38,40
762,73
Muara Badak
27,45
790,78
New Samarinda
27,45
790,08
Sambutan 10,98 1006,20 Kota Bangun
21,96
817,81
Bukit Biru
21,96
825,97
Embalut
60,40
767,64
Tengkawang
76,90
734,52
Harapan Baru 27,45 78,52 Bukuan 16,47 879,23 Karang Joang
32,90
748,81
Manggar Sari
10,98
978,82
New Balikpapan 32,90 745,95 Industri
27,45
770,53
Kariangau
21,96
807,89
Petung 21,96 807,42 Longikis 21,96 808,89 Kuaro
27,45
770,08
Grogot
21,96
812,38
Komam
21,96
810,37
Tanjung Selor 21,96 803,21 Total
642,00
986,10
808,29
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v1i1/101 Table 3.
RESULT ECONOMIC ANALYSIS
No.
Substation Capacity PV .
Payback Period
IRR
ROI
(%)
Maloy
21,96
23,66
Sangatta
27,45
23,78
Teluk Pandan
38,40
24,17
Muara Badak
27,45
23,10
New Samarinda
27,45
23,10
Sambutan 10,98 17,71 Kota Bangun
21,96
22,53
Bukit Biru
21,96
22,22
Embalut
60,40
24,19
Tengkawang
76,90
25,26
Harapan Baru 27,45 23,32 Bukuan 16,47 20,92 Karang Joang
32,90
24,53
Manggar Sari
10,98
18,47
New Balikpapan 32,90 24,66 Industri
27,45
23,97
Kariangau
21,96
22,94
Petung 21,96 22,96 Longikis 21,96 22,90 Kuaro
27,45
23,69
Grogot
21,96
22,75
Komam
21,96
22,83
Tanjung Selor 21,96 23,13 Total
642,00
4,90
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v1i1/101 Figure 5.
Planning Design PV Rooftop for Subtation Usage The results in Table II show the total PV studied using the PV System application.
addition, it can be seen that the energy that can be generated per year that can be used for the auxiliary needs of the substation is 986.
10 MWh per year.
The total usage of the North Kalimantan auxiliary substation in 2023, based on primary data measurements, is 3,285 MWh.
Based on the table above, it can be concluded that PV rooftop installation can reduce auxiliary substation consumption by 30.
01% per year.
This means that the use of rooftop PV at the substation can reduce the companyAos burden by IDR 1.
479 billion per year for the substation environment in Kalimantan.
On-grid PV system that supports curtailment In general, the curtailment of rooftop PV can be explained.
If the auxiliary load is small while the PV supply is excessive, the excess PV cannot be absorbed by the load, or, in other words, wasted.
However, this will not happen because, with the on-grid PV configuration, the excess PV supply is sent to the grid.
As it is known, the substation is a load center that is channeled through a 20 kV repeater.
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v1i1/101 Figure 6.
Single Line Diagram Configuration PV in Manggar Sari Substation Economic analysis results: payback period .
IRR (%).
ROI (%) This study is based on the Levelized Cost of Electricity (LCOE) price of PV technology, which is lower than coal technology .
Based on the results of the study, it is evident that the LCOE price of rooftop PV is lower compared to the LCOE price of coal technology.
Based on Table i, the average value of the payback period for PV installation in 23 substations is 4.
9 years.
This means that with the investment and operating parameters entered in the application, the investment made will be recovered after 4.
9 years and will be profitable for the company in the following year.
The parameters included in the calculation of the economic analysis are a project life of 25 years, an inflation rate 65%, a discount rate of 5%, an electricity sale price of IDR 1,500/kWh, and the investment and operating values of the PV systems to be installed.
The operating value in this case includes the preliminary parameters of the inverter or the lifetime of the The assumption of 7 years means that the inverter will be replaced after 7 years of use, while the PV panels will not be replaced during the life of the project.
Table i also shows the return-on-investment ROI (%) and the internal rate of return IRR (%).
The average value of the IRR is 22.
9%, and the ROI is 206%.
This value indicates the effectiveness of an investment over the life of the project.
Some points that can be recommended based on this re- search in the future to improve this research are as follows:
This research recommends a simulation using an ap- plication : The researchAithe technical and economic analysis of PV rooftop installation for substation auxiliary needsAican be strengthened with a prototype or real experiment in the field by taking a case in one of the substations.
This can strengthen the argumentation of this research.
This research can be implemented on a larger scale : In its implementation, this research can be widely implemented on a scale of more than one province, national, and even international scales to support the acceleration of the energy This is because the aid has a typical design.
Use of primary irradiance data : The use of primary irradiation data can determine the amount of energy that can be produced by rooftop PV throughout the year.
Using primary irradiation measurements rather than the existing database in the PV Syst application can make the study more accurate.
Optimization study using Battery Energy Storage Sys- tem (BESS) : the use of BESS can overcome the intermittency effect of rooftop PV, although BESS currently has a high economic value based on the levelized cost of electricity (LCOE) .
Finally, the author understands that there are still shortcom- ings in this study.
Suggestions and constructive criticism are welcome through the authorAos email.
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v1i1/101 Conclusion Based on this research, it can be concluded that :
A Solar energy is the most suitable renewable energy source for use in the substation Solar energy can be harnessed and converted into electrical energy by using rooftop photovoltaic (PV) systems, which can be used to increase the efficiency of the substationAos auxiliary kilowatt-hour .
A The PV Syst programme is used to analyse the technical and economic aspects of PV rooftop installations in substations.
A Through simulations conducted at 23 substations through- out East Kalimantan, it was determined that a total of approximately 986 MWh per year, or 30.
01% of the total 3,285 MWh in 2023, can be saved by reducing the substation auxiliary kilowatt-hour .
A After the Break Event Point (BEP) period, the conversion of the average production price of IDR 1,500 Rp/kWh into rupiah results in annual savings of IDR 1.
47 billion.
The average BEP period is 4.
9 years.
References