ITB Graduate School Conference

A Synthesis and Characterization of ZIF 67 CTAB-Assisted for Supercapacitor Electrode Active Material

Fri, 10 Jan 2025 00:00:00 +0800

This study investigates the influence of adding hexadecyltrimethylammonium bromide (CTAB) on the morphology and electrochemical performance of ZIF-67, compared to ZIF-67 synthesized without CTAB. The addition of CTAB results in smaller ZIF crystal sizes, which enhances the diffusion capability of electrolyte ions. CTAB-assisted ZIF-67 was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) to confirm the material's structure and morphology. Electrochemical performance was evaluated through cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements. The findings revealed that CTAB enhances crystallinity, as observed in XRD analysis, and reduces particle size from an average of 1692 nm to 1057 nm, as measured by SEM. Electrochemical testing further demonstrated that the addition of CTAB during ZIF-67 synthesis increased the specific capacitance from 98.2 F/g to 104.8 F/g in a 3M KOH electrolyte at a current density of 1 A/g. Based on these results, CTAB-assisted ZIF-67 shows great potential as an active electrode material for supercapacitors.

Density Functional Study on Acid Stability of Mn, Ni, and Fe Dual Atom Catalyst Active Sites Embedded in Graphene

Muhammad Lukmanul Hakim, Adhitya Gandaryus Saputro, Ganes Shukri — Mon, 20 Jan 2025 00:00:00 +0800

This study investigates the stability of Mn, Ni, and Fe dual atom catalyst (DAC) embedded in the basal plane of 2D graphene using density functional theory (DFT) calculations. Our results indicate that these DACs exhibit optimal performance only under specific alkaline conditions. Pourbaix diagrams were constructed to assess the stability of both configurations, revealing that Mn DACs offer a broader operational range in the unpoisoned state compared to Fe and Ni DACs. For the ortho configuration, the active sites are predicted to remain unpoisoned, avoiding adsorption by intermediates such as O* and OH*. However, the para configuration of all three DACs remains functional only in their poisoned states. These findings provide valuable insights for the design of DAC-based ORR catalysts, suggesting that ortho configurations should be studied under conditions where the active sites remain bare, while para configurations should be investigated under poisoned states.

Feasibility Study of a Hybrid Power Plant (Solar and Diesel Power Plant) on Kerayaan Island, South Kalimantan

Hidayah Cahyani Ghufron, Poetro Lebdo Sambegoro, Agustriadi Agustriadi — Mon, 20 Jan 2025 00:00:00 +0800

This study investigates the feasibility of implementing a hybrid power generation system combining solar power (PLTS) and diesel generators (PLTD) on Kerayaan Island as a solution to provide 24-hour electricity, reduce fuel consumption, and lower greenhouse gas (GHG) emissions. By incorporating battery storage, this hybrid system significantly decreases fuel usage, reduces annual operational costs, and achieves a lifetime reduction in GHG emissions by 11,867.4 tonnes of CO2. Financial analysis confirms the project's viability, with a Net Present Value (NPV) of Rp 11,392,864,224, an Internal Rate of Return (IRR) of 30.52%, a Payback Period of 3.8 years, and a Return on Investment (ROI) of 231.8%. From a network modeling perspective, this system has minimal losses, amounting to 0.0005 MW. Overall, the project demonstrates strong feasibility from technical, economic, and environmental perspectives, highlighting its
potential as a profitable and sustainable investment.

The Absorber Layer Variation Effect on the Performance of Sn-Based Perovskite Solar Cell

Mon, 20 Jan 2025 00:00:00 +0800

Addressing the critical need to remove harmful lead from commonly used metal halide perovskite solar cells (PSCs), finding efficient and stable lead-free perovskite alternatives is essential. This study presents a performance analysis of lead-free, all-inorganic Sn-based PSCs using SCAPS-1D is presented. The solar cell architecture used in this research is FTO/TiO₂/FASnX₃/PTAA/Au (X = Br, Cl). The results reveal that absorber layer FASnBr₃ achieves the highest power conversion efficiency at 19.67%, positioning it as a promising candidate for enhancing perovskite solar cell performance. The suggested device structure and parameters not only advance these simulation efforts but also provide a new strategy for optimizing the structure of lead-free PSCs, thereby opening new pathways for future research in this field.

A Methodology for Synthesizing Cataclysmic Variable Populations Using the Output of the MESA Stellar Evolution Code

Aulia Rifaldi Kusuma Putra, Mahasena Putra — Mon, 20 Jan 2025 00:00:00 +0800

This paper presents a methodology for synthesizing populations of cataclysmic variables (CVs) using the MESA stellar evolution code. We construct a grid of binary systems with varying initial white dwarf progenitor masses, companion star masses, and orbital periods, and evolve these systems through pre- and post-common envelope phases. Preliminary results reveal diverse evolutionary pathways, including standard CV formation, mergers, double white dwarf formation, and systems that bypass Roche lobe overflow. These outcomes underscore the complexity of binary evolution and the need for refined models, particularly for common envelope ejection. We discuss the implications of our findings and outline future work incorporating statistical distributions for initial binary parameters to generate synthetic CV populations that can be compared with observational data, thus aiming to improve our understanding of CV formation and evolution.

Floating Photovoltaic Plant: A Review

Cahyaningsih Wilujeng, Sigit Tri Wicaksono — Mon, 20 Jan 2025 00:00:00 +0800

Floating photovoltaic (FPV) systems have emerged as a promising alternative to traditional land-based solar energy solutions, offering a sustainable and efficient approach to harnessing solar energy. The discussion of the topic provides a comprehensive review of the technical, economic, and environmental aspects of FPV technology. It examines the performance ratio, levelized cost of electricity, and compares FPV systems with ground-mounted, rooftop, and canal-top, offshore solar installations. The potential advantages of FPV systems, such as higher energy yields and reduced environmental impact, are discussed, highlighting their ability to conserve land and minimize water evaporation when deployed on water bodies. The review also explores the economic feasibility and technical parameters of FPV systems, including design requirements, energy demand, weather forecasting, and temperature and heat transfer coefficients. The results of this study conclude some of the need for further research to optimize FPV system performance, assess environmental impacts, and enhance economic viability. It calls for future studies to focus on data analysis and the development of innovative solutions to overcome current limitations.

Synthesis and Characterization Ni/Fe-MOF and Its Performance for Supercapacitor Application

Mon, 20 Jan 2025 00:00:00 +0800

Metal-organic frameworks (MOFs) are widely used for supercapacitor electrodes due to their large surface area, high porosity, and adaptability. However, the low conductivity of pure MOFs limits their application as electrode materials. Various techniques are employed to overcome this, including creating bimetallic MOFs or making a composite. This study focuses on the novel bimetallic Ni/Fe-MOF, comparing its characteristics to Ni-MOF. The synthesis of MOFs is achieved using a single-step solvothermal method at 150 ^oC for 48 h, using terephthalic acid (BDC) as ligans. For solvent, ethylene glycol is added as a capping agent. Ni/Fe-MOF exhibits high capacitive properties, with a specific capacitance of 688 Fg^-1 at 0.5 Ag^-1. Both have almost the same Flake-like morphology. These findings suggest that bimetallic Ni/Fe-MOF using solvothermal are promising candidates for improving Ni-MOF performance as supercapacitor electrodes, potentially advancing energy storage technology.

Monitoring of Thermal Variations in Geothermal Activity in the Mount Sirung Field, East Nusa Tenggara with Satellite Imageries

Iga Kusumadewi, Suryantini Suryantini — Mon, 20 Jan 2025 00:00:00 +0800

Mount Sirung Geothermal Field is one of the geothermal potentials that will be developed by the State Electricity Company (PLN) with a planned capacity of 5 Mwe. Geologically, Mount Sirung is located in a location with active volcanism and tectonism. In the context of exploration, knowledge is needed about the influence of volcanism and tectonism activities on geothermal fluid flow. The research was conducted with a remote sensing approach using ASTER Thermal Infra-Red (TIR) images acquired at night to monitor thermal variations through land surface temperature (LST) followed by analysis of high-resolution visible images (SPOT images) and Landsat 8 to determine the distribution of hydrothermal alteration for ten years (2011-2022). The results of this study show that there are changes in thermal variations and the distribution of hydrothermal alteration associated with volcanism and tectonism activities.

A Literature Review on Optimal Placement of Electric Vehicle Charging Stations

Rahmad Sulistyanto, Hasrini Sari — Mon, 20 Jan 2025 00:00:00 +0800

Indonesia's greenhouse gas emissions were almost 697.75 million tons in 2022. The largest source of emissions is from the supply side, which accounts for around 50% of total emissions. On the demand side, the transport sector is the largest source of emissions, with 90% of total emissions coming from road transportation. Switching to electric vehicles (EVs) is one of the easy strategies to
implement to reduce emissions. Electric vehicle charging station (EVCS) planning has a strategic impact on promoting the use of EVs. This paper presents a comprehensive literature review on optimal EVCS placement, covering models and methodologies, including GIS-based approaches, machine learning techniques, multi-criteria decision analysis (MCDA), and advanced optimization algorithms. The aim is to analyze trends, identify gaps, and synthesize findings to comprehensively understand effective EVCS placement strategies, contributing to Indonesia's goal of achieving a low-carbon future. The findings in this paper highlight the importance of integrating robust optimization models into national infrastructure plans to support sustainable growth in EV adoption.

Mapping Geological and Geochemical Suitability to Determine Geothermal Favorability Using Spatial Analysis in the Ungaran Geothermal Field, Central Java, Indonesia

Muhammad Rully Muchni, Suryantini Suryantini — Mon, 20 Jan 2025 00:00:00 +0800

The Ungaran Geothermal Field in Central Java, Indonesia, holds significant potential for geothermal energy exploration due to its volcanic origin and active geothermal manifestations, such as fumaroles, hot springs, and hydrothermal alteration zones. Additionally, its strategic location in one of Indonesia's dynamic and rapidly growing provinces, with a population exceeding 36 million in 2023 and thriving industrial development, underscores strong market potential for geothermal power plant (PLTP) development to meet the region’s high energy demand. This study utilizes Geographic Information System (GIS)-based spatial analysis to integrate six thematic layers—faults, volcanic domes, eruption sources, fumarole manifestations, hot springs, and hydrothermal alteration zones—collected through geological and geochemical surveys conducted by PT PLN (Persero) in 2019. Using the Index Overlay method, these layers were analyzed to assess geological and geochemical suitability for geothermal resource development. The results indicate that Gedongsongo and
Kendalisodo exhibit the highest suitability values, making them priority targets for further exploration. This approach demonstrates the effectiveness of GIS in integrating diverse datasets to enhance predictive accuracy, support strategic
exploration decision-making, and promote sustainable geothermal resource utilization in dynamic regions such as Central Java.

Study on the Use of Heliport as Landing and Take-off Sites for Urban Air Mobility

Raisul Qarni, Taufiq Mulyanto — Mon, 20 Jan 2025 00:00:00 +0800

UAM (Urban Air Mobility) is a new mode of transportation to move passengers or goods from one place to another that is previously less or not yet served by current aviation in urban areas. To facilitate UAM operations, infrastrucutre for landing and take-off is essensial. Since UAM vehicles have the same VTOL (Vertical Takeoff and Landing) capabilities as helicopters, heliport serve as the most comparable infrastructure. This study examines the potential use of heliport for UAM operations, referencing guidelines and regulations from ICAO, EASA, and FAA. As a case study, a comparison is made between the landing and take-off requirements of the Bell 505 helicopter and the UAM vehicle Joby S4, based on their unique specifications. Additionally, an analysis of heliport characteristics in Indonesia was conducted. Out of the 38 heliports analyzed, 24 met the landing and take-off criteria for the UAM Joby S4. This suggests that UAM could operate in Indonesia using the existing heliport infrastructure, with necessary improvements such as charging facilities.

Calcium Oxide Nanoparticles for Chromium (VI) Adsorption: Green Synthesis and Adsorption Studies

Dandy Firmansyah Rifli, Maulana Maulana, Suhendra Suhendra, Syukrya Ningsih — Mon, 20 Jan 2025 00:00:00 +0800

The purpose of this study was to synthesize and characterize calcium oxide nanoparticles from Lokan shell using the top-down method with thermal decomposition and then applied to the adsorption of Cr (IV) metal ions. The results of the analysis of the CaO content of the Lokan shell were determined to be 97.513% by XRF analysis. The study of surface morphology and functional groups of calcium oxide as an adsorbent was carried out using SEM, XRD, and FTIR. Adsorption efficiency and capacity with variations in concentration and contact time were studied from the results of AAS analysis, showing an optimum adsorption capacity of 4.606 mg/g. In this study, CaO was identified as an environmentally friendly and effective adsorbent for removing Cr(IV) metal from water samples.

State-Of-Health Estimation for Lithium-Ion Batteries Using Supervised Machine Learning: XGBoost

Muhamad Maulanal Haq, Irsyad Nashirul Haq, Justin Pradipta — Mon, 20 Jan 2025 00:00:00 +0800

Batteries are energy storage systems used in almost every aspect. As the battery will degrade over time as it is used, the Battery Management System (BMS) needs to be able to monitor its health so that the right battery replacement time can be predicted. Several State-of-Health (SoH) estimation methods have been studied, one of which is the data-driven method. This paper proposed SoH estimation for universal lithium-ion batteries using supervised machine learning:
XGBoost that trained with only one battery material, which is Lihtium-NickelCobalt-Alumunium (NCA). From Model evaluation results show that the model is able to predict well on other data with the same material as the training data with RMSE 1.4320% MAE 0.9174% and MAPE 0.0100%. However, to make predictions on other types of material data, the model has difficulty because XGBoost is not able to make good predictions outside of the training data.

A Modified Firefly Algorithm for Maximum Power Point Tracking (MPPT) Using Sepic Converter Under Shading Condition

Ardian Bayu Wicaksono, Burhanuddin Halimi — Mon, 20 Jan 2025 00:00:00 +0800

This paper presents a method that modify firefly algorithm method, the existing firefly algorithm method uses the principle of spreading several duty cycles which are later compared to each power gain from the spread and the best one is taken. In this
proposed method, the firefly algorithm computation is being simplified and combined with perturb and observe control so the time to reach the global maximum power is reduced and the output power is not fluctuating. To control the output power the SEPIC
Converter topology is used. To ensure the maximum power generated, the duty cycle of the SEPIC Converter is adjusted using modified firefly algorithm control. Then it will be compared with existing firefly algorithm and perturb and observe control to verify the proposed method is faster and not fluctuating.

Understanding Optimal Designs of Public Electric Vehicle Charging Station for Fostering Electric Vehicle Adoptions: A Review Study

Dedy Atryomadepa, Fathiro Hutama Reksa Putra — Tue, 21 Jan 2025 00:00:00 +0800

This study investigates the design and specification of Electric Vehicle Charging Stations (EVCS) located in rest areas and shopping malls (malls) in East Java, Indonesia. By employing conjoint analysis, the research identifies key consumer preferences and critical factors that influence the adoption and usability of EVCS. The design of Public Electric Vehicle Charging Stations (PEVCS) plays an important role in driving electric vehicle (EV) adoption by overcoming barriers such as “range anxiety,” accessibility, and high infrastructure costs. Research shows the need for a data-driven approach to determine optimal locations, improve usage efficiency, and support dynamic subsidy policies that balance infrastructure investment and EV growth. Integration of PEVCS with fast charging technology, renewable energy, as well as global standards, can accelerate the transition to low-emission transportation. In addition, perceived accessibility to users, especially in dense and remote urban areas, is a key factor in increasing public trust in the charging network. A holistic approach involving governments, infrastructure providers, and vehicle makers is needed to ensure the sustainability of the EV ecosystem.

Bioequivalence Profile Prediction of Favipiravir Using Everted Gut Sac

Mon, 20 Jan 2025 00:00:00 +0800

Favipiravir is one of broad-spectrum antiviral drugs approved for the treatment of the influenza virus and SARS-CoV-2, it is known to have inhibitory activity towards RNA dependent RNA polymerase (RdRp). The permeability of Favipiravir in tablet form was conducted using an everted gut sac model for evaluating ex vivo drug absorption as an approach before starting the Pivotal Bioequivalence Study. One formulated Favipiravir tablet 200 mg by Kimia Farma was selected.
Avigan® 200 mg manufactured by Fujifilm Toyama Chemical Co. Ltd was used as reference. In vitro comparative dissolution testing and absorption experiments were conducted. Ex Vivo absorption experiment was developed by using an everted gut sac from male rats intestinal. Absorption rate was used to demonstrate drug molecule intestinal permeability. The rate between test and reference drug was evaluated using a paired student T-test. The resulting data is used to make the bioequivalence study decision. Open-label, randomized, single-dose, two-period, two-sequences, crossover bioequivalence study was carried out under fasting conditions which included 30 healthy adult male and female subjects. Bioequivalence pharmacokinetics parameters assessed in this study were Cmax and AUC0-t. Similarity factor (f2) of comparative dissolution testing between test and reference drug was more than 50 in three mediums (pH 1.2; pH 4.5; pH 6.8). Absorption rates of test and reference drugs were not significantly different (t =0.6683 (< t critical 2.571). Favipiravir tablets produced by Kimia Farma have similar absorption rates compared to the reference drugs. The Bioequivalence study result was satisfactory. The geometric mean ratios of the test drug to the reference drug (90% CI) were 101.27% (96.89-105.86) for AUC0-t and 101.22% (96.80-105.84) for Cmax. All values were within the accepted bioequivalence range of 80.00-125.00% for both AUC0-t and Cmax.

Thermal Simulation of the TIAC System for Muara Karang CCPP Block 2: Feasibility Study for Power, Efficiency, and Emission Improvements

Alfa Ageng Santoso, Ari Darmawan Pasek — Mon, 20 Jan 2025 00:00:00 +0800

This study conducted a thermal simulation of the turbine inlet air cooling (TIAC) system for Muara Karang combine cycle power plant (CCPP) Block 2, focusing on its feasibility for enhancing power output, efficiency, and reducing greenhouse gas (GHG) emissions. Implementing TIAC on gas turbine generator) GTG 2.1 increased power output from 235 MW to 252.2 MW gross of power, reduced the heat rate, and improved plant efficiency. Financial analysis showed viability, with the internal rate of return (IRR) rising from 14.36% to 14.44%, surpassing PT. PLN's 9.28% threshold, and the net present value (NPV) increasing by Rp. 31.1 billion. GHG emission intensity decreased from 0.6018 kgCO2e/kWh to 0.6007 kgCO2e/kWh.

Development of an Operational Readiness Assessment Model for Gas Engine Power Plants (PLTMG) to Use Gas as the Primary Fuel at PT PLN (Persero) in Maluku and North Maluku Regions

Apprilian Kurniawan, Joko Siswanto — Mon, 20 Jan 2025 00:00:00 +0800

The enactment of Law No. 16 of 2016 on the Ratification of the Paris Agreement under the United Nations Framework Convention on Climate Change establishes a legal framework for Indonesia's commitment to addressing global climate change. One of Indonesia's key commitments is achieving the Nationally Determined Contribution (NDC) target of reducing greenhouse gas emissions by 29% by 2030, supported by the Electricity Supply Business Plan (RUPTL) through strategies for transitioning to clean energy. PT PLN (Persero) Unit Pelaksana Pembangkitan Maluku, which manages the Gas Engine Power Plant (PLTMG), plans to transition from using biodiesel (B35) to natural gas to reduce carbon emissions and support the NDC target. This study aims to evaluate the operational readiness of power generation units in the fuel transition process using a multidimensional approach encompassing the dimensions of Infrastructure & Technology, Organization, Operations, Human Capital, Regulatory, and Social & Economic. This approach provides a comprehensive assessment of technical readiness, human resources, policies, and socioeconomic aspects, which are particularly relevant for regions such as Maluku and North Maluku with complex infrastructure challenges.By adopting a readiness level model, this study provides a detailed overview of operational readiness stages and areas requiring improvement. The findings are expected to serve as a reference for PT PLN (Persero) in developing plans to enhance operational capacity based on clean energy, while also supporting the achievement of sustainable energy transition targets in Indonesia.

Improvement of Voltage Regulation on the 150kV Isolated System: Study Case of Isolated Ketapang System

Muhamad Rahman Hakim — Mon, 20 Jan 2025 00:00:00 +0800

The Isolated transmission line in the Ketapang system is one of several systems in the Khatulistiwa, West Kalimantan system that is still not connected to the main grid. Due to the long distance, low load and there is no large plant in the Ketapang isolated system there is potential for a voltage violation on isolated transmission lines in the Ketapang system above the service voltage limit. With the 150 kV nominal voltage still not up to standard (average 127 kV), it is necessary to improve service. This improvement in service certainly needs to be balanced with an increase in equipment performance, therefore it is necessary to improve methods.

Lightweight WaSR-T Network for Detection Boat Approaching a Tsunami Early Warning System

Wayan Wira Yogantara, S Suprijanto, A. A. N. Ananda Kusuma, Yuki Istianto — Mon, 20 Jan 2025 00:00:00 +0800

A tsunami early warning system using buoys is vital for early warning of tsunami waves. Its vulnerability to tampering and even vandalism emphasizes the need for an object detection vision system for tsunami buoys. Moreover, researchers typically position these buoys at considerable distances from the seashore. The current tsunami early warning system lacks an object detection system capable of providing warnings about the presence of other disturbing objects. Hence, any system vision must incorporate object detection with energy efficiency. This research studies various efficient object detection network models that support object detection systems for these tsunami buoys. WaSR-T model network with temporal context was developed and equipped with a lightweight encoder MobileNetV3 to run on a single board computer. Experiments on a Jetson Nano revealed that lightweight WaSR-T using the MobileNetV3 encoder can detect ships in various sea conditions. Although the test results show less than optimal performance than the original network model, the experiments highlight that the lightweight WaSR-T remains the most promising for object monitoring on tsunami buoys, given its low memory requirements. Researchers can also implement it in other mid-ocean monitoring applications, such as rigs and marine platforms.

Comparison of Inflow Forecasting Methods in Optimizing Operation and Maintenance Pattern Study Case: Bakaru Hydropower Plant

Eldi Amrillah, Ferryanto Ferryanto, Gea Fardias Mu’min — Mon, 20 Jan 2025 00:00:00 +0800

Hydropower is an exceptionally reliable and environmentally friendly power generation technology in today's energy landscape. Its eco-friendliness significantly aids in reducing greenhouse gas emissions. However, maintaining the reliability and performance of hydropower plants is paramount to ensuring a stable electricity supply. One of the crucial factors influencing the effectiveness of operation and maintenance planning for hydropower plants is the availability of water inflow. To achieve optimal performance and reliability, it's essential to have a clear understanding of how much water the plant can harness for energy generation. The primary objective of this paper is to conduct a comprehensive and in-depth exploration of various methodologies for forecasting water inflow, with a particular focus on empirical forecasting methods. These forecasting methods are essential in enhancing the planning and execution of operation and maintenance activities in water resource management and hydropower generation. In order to illustrate the practical use of these methodologies, the paper presents a case study on inflow forecasting for the Bakaru Hydropower Plant. This case study utilises empirical methods such as Multiple Linear Regression (MLR), Support Vector Machines (SVM), Artificial Neural Networks (ANN), and Seasonal Autoregressive Integrated Moving Average (SARIMA) to predict water inflow patterns. The results of the case study indicate that the most effective method for information forecasting at the Bakaru Hydroelectric Power Plant is the Artificial Neural Network (ANN) method, with an R-squared value of 0.39 and a Root Mean Square Error (RMSE) of 25.15.

Effect of Electron Transport Layer Donor Density on the Performance of FASnI₃ Perovskite Solar Cells

Mon, 20 Jan 2025 00:00:00 +0800

This study focuses on enhancing the efficiency of FASnI₃-based perovskite solar cells by investigating variations in electron transport layer (ETL) donor density. The solar cell architecture used in this research is FTO/ETL/FASnI₃/PTAA, with ETL materials varied between TiO₂, ZnO, and SnO₂ and donor density varied from 10¹⁶ to 10²² cm^-3. The results demonstrate that ZnO exhibits the highest power conversion efficiency, reaching 20.23%, making it a promising candidate for improving the performance of perovskite solar cells. This investigation underscores the impact of donor density in ETL materials on enhancing the efficiency of lead-free perovskite solar cells.

Study of reservoir characteristics: pH, dissolved and precipitate minerals in Atadei geothermal field, Lembata Regency, East Nusa Tenggara

Indah Amalia, Suryantini Suryantini — Mon, 20 Jan 2025 00:00:00 +0800

Based on consultant X’s reports (2020), there are 24 surface manifestations found in the Atadei geothermal field including fumaroles/steam vents with temperatures ranging from 80°C - 98°C, hot springs with temperatures around 34 - 39.6°C, cold springs and altered rocks. Exploration wells AT-1 and AT-2 were drilled by DISDM in 2004, but no steam or water was found at depth. To determine the reservoir characteristics, geochemical modeling with PHREEQC was conducted. From the saturation index modeling, it is known that the hot and cold springs in the study area are entirely oversaturated with silica minerals (quartz and chalcedony). This is presumably because the host rock is andesitic lava rock with a silica content of 55 - 65%. In addition, most of the springs are also oversaturated with carbonate minerals (aragonite and calcite) but have not yet formed deposits around the manifestations due to the condition of the springs which also predominantly contain silica minerals. Based on geochemical modeling with forward modeling, it is known that the reservoir characteristics in the study area in the temperature range of 180 - 240°C have an acidic pH ranging from 4.64 - 5.18. This is supported by the composite log data of the AT-1 well where in the depth interval of 608 - 830.5 m, the reservoir is suspected to be a chloride sulfate type with a pH that tends to be low (acidic) characterized by the presence of acidic alteration minerals, namely pyrophyllite and dickite (Reyes, 1990).

Exploring Sustainable Alternatives: A Comparative Study of Palm Oil and Mineral Oil as Coolants in a 150 kV Transformer

Maulana Bayu Pamungkas, Ari Darmawan Pasek — Mon, 20 Jan 2025 00:00:00 +0800

This study investigates the feasibility of using palm oil-based vegetable oil as a sustainable alternative to Nynas mineral oil in 150 kV transformers. While mineral oil is commonly used due to its high breakdown voltage and thermal stability, it is nonrenewable, has poor biodegradability, and presents environmental risks. In contrast, palm oil is abundant, renewable, biodegradable, and cost-effective, making it a promising substitute. Using the Lumped Capacitance Method (LCM) 2 system, we evaluated the thermal performance of both oils, focusing on their heat dissipation capabilities and temperature distribution within transformers. The results indicate that palm oil-based oil achieves thermal performance comparable to mineral oil, effectively maintaining operational temperatures within safe limits. Additionally, palm oil demonstrates a slightly higher heat transfer efficiency than mineral oil, with the
temperature T₁ for Palm Oil is approximately 25.707135℃, after cooling down from an initial temperature (T₀) of 30℃ to the environmental temperature (T∞) of 25℃. In comparison, mineral oil's temperature (T₁ ) is approximately 25.750410℃ under the same conditions. These findings highlight palm oil as a viable, eco-friendly alternative for transformer cooling, particularly in regions with
abundant palm oil resources, aligning with sustainability goals while ensuring transformer reliability.

Computational Study on the Effect of Anode Layer Variation on the Performance of FASnI3-based Perovskite Solar Cells

Mon, 20 Jan 2025 00:00:00 +0800

The development of lead-free perovskite solar cells (PSC) is gaining
traction due to concerns over the toxicity of lead-based materials. This study
explores various anode materials as back contact of tin-based perovskites with a
complete configuration consisting of FTO/TiO2/FASnI3/PTAA/Anode to optimize
the performance of FASnI3-based PSC. Using SCAPS-1D and density functional
theory (DFT) simulations, we analyze the impact of varying work functions of
various metals, including several alloy metals, on the device's performance and
stability. The simulation results indicate that variations in the work function of
metal contacts ranging from 4.3 eV to 5.0 eV affect the Power Conversion
Efficiency (PCE) of the PSC. Utilizing DFT calculations enables the confirmation
of the accuracy of the work function parameter by computing the difference
between vacuum potential and Fermi energy, further validating the device’s
capability with PCE up to 17%. These results highlight the significance of
selecting suitable anode materials to improve both the efficiency and durability of
tin-based PSCs based on their layer configuration. Key properties of the anode
material, such as work function and electrical conductivity, can optimize the
charge extraction, enhancing overall device performance

Optimizing Marketing Strategy for PT PLN Through Customer-Based Clustering Using Machine Learning

Anton Sujarwo, Fahdzi Muttaqien, Yandika Restu W, Zuhri Arieffasa S — Mon, 20 Jan 2025 00:00:00 +0800

PT PLN (Persero) operates across Indonesia, with branch units managing diverse customer categories and volumes, including industrial, business, and residential customers. This variation in customer profiles presents challenges in optimizing marketing strategies and determining appropriate marketer allocations for each unit. To address this, this study applies machine learning, specifically the K-Means clustering algorithm, to group PLN units based on the number and type of customers managed. The Elbow Method identifies the optimal number of clusters, ensuring that the grouping reflects meaningful distinctions among units. Through clustering, PLN aims to enhance marketing strategies by tailoring resource allocation and optimizing marketer distribution. This study demonstrates that customer-based clustering can provide actionable insights for targeted marketing and resource optimization within PLN’s operational framework.

Calcined Duck Eggshells as Sustainable Adsorbents for Lead Removal from Laboratory Waste

Hesty Nuur Hanifah, Ginayanti Hadisoebroto, Mochammad Taufik Sukmanaputra — Mon, 20 Jan 2025 00:00:00 +0800

Pb metal is a heavy metal that comes from wastewater and can cause very big problems for organisms and the environment because it has high toxicity and is non-biodegradability. One way to solve the problem of heavy metal pollution is using the adsorption process. Duck eggshells are household and commercial waste that have not been utilized to their full potential. This study aims to determine the effectiveness of the adsorption of duck eggshells that have been activated physically and chemically by determining the optimum pH, optimum contact time, and optimum mass as well as knowing the characteristics and content of the egg shell ducks. Duck eggshells were physically activated by being heated in a high temperature of 900 0C and chemically activated through immersion process using H3PO4 for 24 hours. Pb Metal was measured using the Atomic Absorption Spectrophotometry tool at wavelength of 283.3 nm. The characteristics and content of duck eggshells were analyzed using the SEM-EDS tool. The results showed that the optimum condition of the duck eggshells in adsorbing Pb metal was at pH 6, optimum time at 75 minutes, and optimum mass of 500 mg with adsorption effectiveness of 94.75%. The results of the examination using the SEM tool showed that the duck eggshells that had been physically and chemically activated had larger pores compared to the duck eggshells that have not undergo the activation process. EDS analysis showed that the elements contained in the shell of duck eggs are carbon elements (C), oxygen (O), calcium (Ca), and phosphorus (P).

The Effect Of PV Positioning On Power Losses In Grid-Connected Micro Hydro Power Plant Systems

Akhmad Iqfaldi, Fathin Saifur Rahman, Nanang Hariyanto — Mon, 20 Jan 2025 00:00:00 +0800

This study rigorously investigates the effects of PV (photovoltaic) placement on the voltage profile and power losses in a grid-connected micro-hydro power system in West Sumatra, Indonesia. The primary objective is to identify optimal PV installation locations that minimize grid power losses while enhancing voltage stability in a 20 kV distribution network. Through comprehensive simulations, the study assesses the different effects of PV placement at different nodes in the network. The findings reveal that PV integration impacts voltage profiles and power losses differently across the network, with some locations showing improved voltage quality and others exhibiting voltage instability, which can lead to operational challenges. Notably, higher PV penetration is associated with increased grid power losses, reaching up to -9,9 % in certain configurations. These results underscore the need for advanced adaptive power control strategies, such as smart inverters and energy storage solutions, to maintain grid reliability. This study offers actionable insights for grid operators and policymakers aiming to balance the benefits of renewable energy integration with the technical requirements for stable and efficient power distribution.

Voltage Drop Mitigation in Comparison Analysis for Low Voltage Shore Connection (LVSC)

Fauzia Dyah Setyowati, Kevin Marojahan Banjar-Nahor, Nanang Hariyanto — Mon, 20 Jan 2025 00:00:00 +0800

This paper is based on an ongoing project to evaluate the voltage stability from shore to ship during connection which is currently a concern for ship operators. The voltage drops produced by the ship motor load during connection affect the anomalies of the electronic equipment on board. Stability Analysis Function (RMS) and Power Flow Analysis are studied for possible operating conditions at low voltage shore connection (LVSC) using Digsilent Power Factory. This study compares Upsize Converter, Transformer On Load Tap Changer (OLTC), Uprate Voltage Setpoint at Substation, and Static Synchronous Compensator (STATCOM) methods for voltage drop mitigation. Simulations shows that STATCOM has the capability to maintain reactive power compensation and Upsize Converter has current limits for balancing voltage during normal and dynamic operation as well as when voltage drops appear

Development of a Sustainability Assessment Model for Transmission Unit Using Business Processes Indicator

Rizky Gian Pratama, Budhi Prihartono — Mon, 20 Jan 2025 00:00:00 +0800

The growing global emphasis on sustainability has emerged as a critical concern across various sectors, including the power and utility industries. As a state-owned enterprise in the electricity sector, PT PLN (Persero) has articulated its strategic sustainability policies in the Corporate Long-Term Plan (Rencana Jangka Panjang Perusahaan or RJPP) and the Board of Directors’ Regulations (Peraturan Direksi or PERDIR) on sustainable business strategies. PT PLN (Persero) also has adopted the Global Reporting Index (GRI) as an objective framework for assessing sustainability performance, which is currently implemented at the corporate level. However, technical guidelines for implementing sustainability as a derivative of these policies remain incomplete, and a sustainability assessment mechanism has not yet been established by the corporation for the transmission unit. Furthermore, PT PLN (Persero) currently conducts performance evaluations only at the strategic and tactical levels, leaving performance assessment frameworks at the process level undefined. Therefore, it is necessary to identify relevant business process indicators aligned with sustainability activities in transmission unit. This study proposes a model and framework for developing business process indicators to assess performance at the operational level. The proposed assessment framework aims to address sustainability issues and challenges faced by the transmission unit, encompassing economic, environmental, social, and governance aspects. The final model resulting from this research is designed to be integrated into the existing performance evaluation framework, forming a component of the Kontrak Manajemen for the transmission unit.

Volcanostratigraphy Study of the Kepahiang Geothermal Field

Mon, 20 Jan 2025 00:00:00 +0800

The island of Sumatra has high geothermal potential as a result of tectonic activity from the Great Sumatran Fault running along the island. This tectonic activity has formed volcanoes and surface thermal activity in various regions, including Kepahiang. This study aims to analyze the geological conditions, geomorphology, and volcanic products in the area, and then classify them according to the Indonesian Stratigraphy Code (1996). The analysis focuses on volcano stratigraphy using satellite imagery, topographic maps, and ridge delineation from Digital Elevation Model (DEM) data. The study will be presented as volcano stratigraphy maps at scales of 1:50,000 and 1:100,000, which can serve as a guide for geothermal resource exploration and utilization in Kepahiang.

A Support Vector Machine Method for SF6 Gas Quality Classification

Mon, 20 Jan 2025 00:00:00 +0800

To meet the need for high reliability, increased load demand, and optimal maintenance strategy improvements, a machine learning-based method is introduced as an assessment approach for gas-insulated switchgear (GIS). Using historical data from different time periods, indicators representing the health level of GIS in terms of the quality of Sulphur Hexafluoride (SF6) gas are extracted using the support vector machine (SVM) algorithm. The data imbalance in the sample is normalized using the Synthetic Minority Oversampling Technique (SMOTE) to improve the accuracy of the training data. By combining inspection results and online monitoring data, the operational condition panorama of each GIS compartment is classified as the model output. Based on data obtained from three hundred and twenty-two GIS compartments in the Surabaya area, the method's effectiveness is demonstrated through sample test results.

Development of Bidirectional Battery Charging Scheduling System Considering SOC Level and Energy Price

Ghiok Nanda Alivsky, Tri Desmana Rachmilda, Arwindra Rizqiawan — Mon, 20 Jan 2025 00:00:00 +0800

Electric Vehicle (EV) technology has advanced to allow bidirectional power flow, enabling EVs to not only consume energy but also supply it back to the grid. However, research on time-based charging and discharging patterns is limited, particularly in Indonesia, where electricity tariffs remain constant throughout the day. This study proposes a time-based control strategy, assuming
dynamic pricing with higher rates during peak hours, to create mutual benefits for EV users and utilities. The system integrates a State of Charge (SoC) management mechanism and a Proportional-Derivative (PD) controller to optimize battery performance and energy flow. Tests at initial SoC levels of 25%, 55%, and 85% reveal that the parameter combination Kp = 0.02 and Kd = 1 achieves the lowest
error, ensuring efficient control. This strategy encourages EV users to sell energy during peak hours, providing financial rewards while helping utilities balance energy demand during critical periods.

Synthesis and Characterization of Nickel Metal-Organic Framework for Supercapacitor Electrodes

Mon, 20 Jan 2025 00:00:00 +0800

A supercapacitor is a device of energy storage that boasts high energy and power density, utilizing an electrostatic double-layer mechanism and pseudocapacitance reactions to store energy. Electrode materials, like nickel, have
garnered attention because of their high theoretical capacitance, availability, simplicity in production or synthesis, and chemical durability. In spite of these benefits, obstacles like poor rate capability and limited cycling properties hinder
its widespread application. Nickel Metal-Organic Framework (Ni-MOF) was produced through solvothermal synthesis at 150°C and applied as a supercapacitor electrode. MOF-based material is chosen as a supercapacitor electrode because of
its oustanding surface area, numerous mesopores, abundant active sites, and good electrical conductivity, all contributing to improving the supercapacitor's specific capacitance. Ni-MOF was synthesized and analyzed using multiple analytical
methods, like X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) study to verify the material's structure and morphology. The Ni-MOF based supercapacitor’s electrochemical performance
was evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). The test findings demonstrate the great potential of this material for highpower energy storage applications by demonstrating that the supercapacitor with Ni-MOF electrodes has a specific capacitance of 90.7 F g-1 at a current density of 0.5 A g-1 .

Evaluating the Challenges of Biomass Co-Firing for Energy Transition: A Review

Robby Eriend, Cahyaningsih Wilujeng, Prihadi Setyo Darmanto — Mon, 20 Jan 2025 00:00:00 +0800

This study explores biomass co-firing in Indonesia’s coal-fired power plants as a strategic pathway to boost the country’s renewable energy transition. It highlights the benefits and challenges of co-firing across three key areas: biomass supply chain mechanisms, economic feasibility, and technical obstacles. Ensuring a steady biomass supply is essential to avoid operational outages, with particular attention to challenges like slagging, fouling, and corrosion. The study reviews optimization models to determine ideal facility locations, effective co-firing rates, and strategies for emissions reduction. Economic viability is assessed using the Levelized Cost of Electricity (LCOE), which underscores the impact of biomass costs on project feasibility. The study further suggests that using additives could enhance combustion efficiency, while managing a diverse range of biomass sources, particularly in resource-rich regions, is crucial for consistent supply and the long-term sustainability of co-firing initiatives. Despite these challenges, biomass co-firing emerges as a promising option for supporting Indonesia’s shift to renewable energy, with significant potential to contribute to the country’s net-zero emissions target by 2060. Addressing economic, technical, and logistical factors is essential for optimizing co-firing and achieving successful, large-scale implementation.

The Acid Zone Delineation In Tangkuban Parahu Geothermal Working Area

Arsyi Hadyan, Suryantini Suryantini — Mon, 20 Jan 2025 00:00:00 +0800

The Tangkuban Parahu Geothermal Working Area is located in West Java, Indonesia, and is dominated by volcanic products from Mt. Sunda and Mt. Tangkuban Parahu. Mt. Tangkuban Parahu was generated after Mt. Sunda eruption which produced large caldera. Acid zone in Tangkuban Parahu GWA becomes important to be studied regarding its origin which associated with intensive volcanic activity up to present days. The study applying the magnetotelluric data to determine the total conductance numbers for identifying anomalies corresponding acid zones. Total conductance with specific amount tied with acid manifestations in some locations to acquire approximate number of acid zones. The acid zone map delivered from total conductance data further calibrated with aleration zones and comprimising structure data. From preceding processes, the study has obtained the 2D distribution map of acid zone in Tangkuban Parahu GWA. The acid zone spread from the Kawah Ratu and Kawah Domas northward to Cijalu, northeastward to Ciater, and southward to Kancah. While Cikole and Amblongan estimated to be area which consist more benign fluids with near-neutral pH.

Probabilistic Methods for Assessing Spare Distribution Power Transformers

Thariq Adha Gumilang, Fathin Saifur Rahman, Nanang Hariyanto — Mon, 20 Jan 2025 00:00:00 +0800

This paper addresses the challenge of determining the optimal number of spare transformers needed to maintain reliability in power distribution networks. Given the critical role of transformers in ensuring uninterrupted power supply, their failure can significantly impact the distribution system's operation. To mitigate these risks, the study explores probabilistic methods, specifically the Poisson Distribution and Markov Models, to optimize the inventory of spare transformers. The reliability criteria guide the analysis, ensuring that the system remains reliable while minimizing the financial burden of maintaining excess inventory. A case study demonstrated the comparison between two probabilistic methods using reliability criteria. The optimal number of spare transformers generated through calculations using both methods shows relatively similar results. The results highlight that while both methods are effective, the Markov Model offers a more comprehensive approach by incorporating additional parameters that accurately reflect actual conditions. This model enables utilities to balance system reliability with cost efficiency, ensuring that spare transformer inventories are maintained optimally without unnecessary expenditure. The calculation results will be compared with historical transformer failure data in the system, which are used as part of the study to validate the calculated data and demonstrate the effectiveness of both methods.

A Review Co-firing Effect of Large-scale Biomass Utilization on Pulverizer Performance

Ahmad Hadiyan Erawan, Prihadi — Mon, 20 Jan 2025 00:00:00 +0800

The increasing need for sustainable energy production has led to extensive exploration of alternative fuel sources and innovative combustion techniques. Co-firing, the simultaneous combustion of biomass with traditional fossil fuels, has emerged as a viable strategy to reduce greenhouse gas emissions (GHG) and diversify the energy mix. This review paper focuses on the specific application of large-scale sawdust utilization as a co-firing material in pulverized coal (PC) combustion systems and its influence on pulverizer performance. The utilization of biomass as fuel in power plants still creates several problems. Challenges and considerations related to integrating large amounts of sawdust into pulverized coal combustion from the perspective of the pulverizer are discussed. From several studies, it was found that the use of biomass tend to increase mill amperes as biomass use increases. 15% biomass use on a mass basis need modification. This limitation prevents increasing the amount of biomass use. Furthermore, optimization strategies and best practices for efficient sawdust co-firing are presented, emphasizing the need to balance environmental benefits with maintaining pulverizer performance. The paper concludes by summarizing key findings and providing insights into future research directions to facilitate informed decision-making in sustainable energy production.

Geological Risks Assessment and Quantification in Ulumbu Geothermal Field, East Nusa Tenggara, Indonesia

Angga Putra Pratama, Suryantini Suryantini — Mon, 20 Jan 2025 00:00:00 +0800

The Ulumbu geothermal power plant is currently operating with a total capacity of 10 MWe. However, the Ulumbu geothermal field still holds the potential for further resource utilization, with at least 40 MW available for the next
development phase. This further development carries risks of failure, making geological risk assessment and quantification crucial for calculating the success of development drilling in terms of resource risks. The method of geological risk assessment and quantification in geothermal exploration has been previously developed and applied to two fields, Galunggung and Patuha. The more frequently this method is applied to other geothermal fields, the more valid it becomes, considering that each geothermal field has its unique characteristics in terms of geothermal play type and resource conditions. This paper applies the geological risk assessment and quantification method to the Ulumbu geothermal field under two conditions: pre-drilling (3G data before 1992) and post-drilling (1996 drilling data and the latest 3G data). The results show that the pre-drilling condition exhibits a higher geological risk compared to the post-drilling condition

Geology Structure Identification in Ranau Lake with Bathymetry and Geoscience Data Integration

Rizcky Ridho Prasetio, Suryantini Suryantini, Tony Widiatmoro — Mon, 20 Jan 2025 00:00:00 +0800

Lake Ranau is one of the areas planned for the development of geothermal power plants owned by PT PLN (Persero). The Lake Ranau area lies in a tectonically active zone formed by the subduction of the Indo-Australian Plate beneath the Eurasian Plate. This region is also intersected by several faults on the island of Sumatra, including the Sumatran Fault. Faults play a critical role in identifying geothermal potential, as they often serve as pathways for heat and fluid movement. To assess geothermal potential, geological, stratigraphic, and lithological studies are conducted to identify permeable zones connected to heat sources beneath the Earth's surface. However, these studies are typically limited to land areas. Since the Lake Ranau Geothermal Working Area (WKP) includes a lake, a specialized study is required to explore the potential presence of permeable zones within the lake. Research aimed at defining permeable zones in the lake has incorporated bathymetric survey data to identify additional faults or structures that may enhance permeability in the Lake Ranau WKP. By integrating bathymetric methods, researchers can gain insights into subsurface structures beneath the lake bed that could act as permeability pathways, contributing to the area's geothermal potential.

Solar Dryer Design For Biomass

Murjayadi Murjayadi, Poetro Lebdo Sambegoro, M. Rajul Kahfie — Mon, 20 Jan 2025 00:00:00 +0800

This study explores the design and performance of a mixed-mode solar dryer for drying biomass to improve the efficiency of co-firing in a power plant. The dryer combines passive and active solar drying methods to effectively operate in various weather conditions. By analyzing the thermodynamics and heat transfer processes within the system, the research evaluates the dryer's impact on biomass quality, particularly its calorific value. A mathematical model is used to predict drying times and optimize design parameters like solar collector size and airflow. The study investigates the relationship between heat requirements, drying efficiency, and biomass quality. Results indicate that the mixed-mode solar dryer effectively dries biomass while preserving its calorific value, offering a promising solution for sustainable and cost-effective biomass drying in power plants.

2D Linear Elasticity Using an Efficient Mollified Collocation Method with Local P-Adaptivity

Syahrir Ginanjar, Lavi Rizki Zuhal, Eky Febrianto — Mon, 20 Jan 2025 00:00:00 +0800

Point collocation method becomes popular in engineering design and analysis in which offers a significant advantage by employing discretized strong form, instead of being averaged over the domain as is the case in weak form approach. Mollified basis functions offer several advantages such as ease of constructing, flexible degree and smoothness, and adaptability to arbitrary partitions. These basis functions are formed by convolving local polynomials within a cell with a smooth kernel called mollifier, which is chosen for its compact support, unit volume, and smoothness. Since mollified basis functions have high order and smoothness, it is possible for us to do local refinement like p-adaptivity, where the polynomial order is chosen to be higher at certain region, one of the examples is stress concentration in linear elasticity problem. The mollified collocation method using p-adaptivity is studied in this paper by evaluating convergence error in linear elasticity plate with a hole problem.

Further Gravity Data Process to Estimate Geological Structure in Tulehu Geothermal Field, Ambon Island

Muhamad Lucky Fernando — Mon, 20 Jan 2025 00:00:00 +0800

Tulehu geothermal field in Central Maluku, managed by PT PLN since 1997, is targeted for a 20 MW power plant by 2025/2026. Initial exploration, including five wells drilled from 2011 to 2018, yielded unsatisfactory results. This study revisits gravity survey data from 2010 and process additional 2019 gravity data focused on the Banda and Banda Hatuasa Faults to refine the structural understanding of the field. Gravity data processing involved complete bouguer anomaly (CBA) mapping and spatial derivatives. The analysis indicates a gravity anomaly pattern decreasing from SW to NE, suggesting a basement elevation drop across the field. First Horizontal Derivative (FHD) emphasize fault boundaries, and Euler Deconvolution points to structural dip directions. Results confirm the Banda Fault as the primary control for geothermal fluid flow, although it appears slightly southward of prior interpretations. The Banda Hatuasa Fault, contrary to earlier assumptions, is identified as a distinct structure north of the Banda Fault. These findings provide essential insights for targeting faults in future drilling plans, enhancing geothermal resource development in Tulehu.

Techno-Economic and Grid Study of Hybrid Diesel Power Plant and Solar Power Plant Systems on Simeulue Island

Malfian Distantio, Poetro Lebdo Sambegoro — Mon, 20 Jan 2025 00:00:00 +0800

This paper aims to conduct a techno-economic and grid analysis of a hybrid Diesel Power Plant and Solar Power Plant system on Simeulue Island. The research focuses on energy analysis and the impact of transitioning from diesel-based generation to solar-based (dedieselization) as a step toward sustainable energy development. Simeulue Island, home to approximately 96,000 residents, is entirely dependent on Diesel Power Plants (PLTD) due to its geographical isolation from Indonesia's main islands. However, the island
possesses considerable solar energy potential, offering a viable renewable energy source that can be utilized year-round. Through hybrid system simulations of PLTD and PLTS using PVsyst, Homer, this research will analyze the required energy generation to meet specific load demands at various times. The proposed photovoltaic (PV) system output capacity is 2.5 MW, utilizing 5,000 PV modules. The simulations indicate that this integration can produce approximately 4,349,203 kWh of solar energy, which contributes to a renewable energy penetration rate of 9.94% of the total load annually. From an economic perspective, the integration of solar
power into the existing diesel system leads to a notable reduction in the Levelized Cost of Energy (LCOE), which decreases from Rp 4,253/kWh to Rp 3,772/kWh.

Subsurface Structure Identification Using Gravity Field Measurement Data Analysis in Songa Wayaua Geothermal Prospect Area

Andri Darmansyah Putra Perdana, Suryantini Suryantini, Tony Widiatmoro — Mon, 20 Jan 2025 00:00:00 +0800

Geothermal prospective area has surface signs, often called surface manifestaations. Prospective area needs to be analyzed using several techniques in terms of geological structure and its interconnection with subsurface structure. The structure can be hypothesized as the geothermal fluid path and become consideration of identification permeable zone that can produce large outcome of drilling results. Songa Wayaua geothermal field is located in Bacan Island, North Maluku Province, Indonesia. Geothermal manifestations are found scattered along the coastal plains from the Songa area to Bukit Langsa, and a hot spring is also found on the Wayaua beach in the southern part. Geological structure on Songa Wayaua geothermal field from previous research still unclear whether geological subsurface structure is related with its surface structure based on data observed. FHD and Euler deconvolution analysis done with a good result corelating subsurface feature with surface structure. FHD and Euler deconvolution result are mostly giving the same result based on horizontal anomaly interpretation. Tawa Fault, Banda-Hatuasa Fault, Sibela Fault and Bukit Bibino Fault are shows good corelation structure with anomaly majority occurred in 0 – 500 meters depth. Those structures probably are permeable structures that could control the existence of surface manifestation, both upflow and outflow.

Server Network Monitoring Notifications and Cluster Analysis through Web Application

Mon, 20 Jan 2025 00:00:00 +0800

A web-based local server monitoring application using Zabbix monitoring tools was developed to fulfill the requirement of monitoring the status of network downtime and network uptime. One of the main requirements is the ability to get real-time notifications if the server has a network problem so that mitigation actions can be taken quickly. In addition, this application is also completed with the feature of sending server downtime and uptime network status to mobile applications (Telegram) and website applications built using the PHP programming language and MySQL database. By sending the status of server network problems to the website that was built, it is useful to illustrate trends and analyze patterns of server network problems, as well as analyze cluster servers based on total network disruption. With this recapitulation, network administrators can make better evaluations and planning to improve server reliability and reduce potential downtime in the future. The Zabbix monitoring tool was chosen because of its comprehensive and flexible ability to monitor various server parameters and the ease of managing and displaying data through an intuitive web interface. The results of this implementation are expected to improve operational efficiency and maintain the continuity of services offered by the server.

Adoption of Electric Motorcycles: Challenges, Influencing Factors, and the Role of Government Regulations: A Literature Review

Romdhoni Nur Huda, Hasrini Sari — Mon, 20 Jan 2025 00:00:00 +0800

The increasing global urgency to address climate change and its adverse impacts has spurred interest in sustainable energy solutions, including electric vehicles (EVs). In Indonesia, the transition from traditional fuel-powered motorcycles to electric motorcycles (EMs) is particularly relevant in underdeveloped regions facing logistical challenges in fuel distribution. This study investigates the determinants of EM adoption by integrating cultural factors within the Unified Theory of Acceptance and Use of Technology (UTAUT). Using a systematic review approach, the research explores demographic, situational, technical, and regulatory factors influencing EM adoption. Data were collected via surveys targeting prospective users, focusing on behavioral intentions rather than actual usage, given Indonesia's early-stage EV adoption. Structural equation modeling was applied to analyze the relationships between constructs,
incorporating variables such as performance expectancy, effort expectancy, social influence, and facilitating conditions. The findings highlight that financial constraints and inadequate infrastructure are significant barriers to adoption. However, factors such as performance expectancy and social influence strongly impact purchase intentions. The study underscores the importance of government intervention through policy enhancements, subsidies, and infrastructure development. Additionally, public education initiatives are crucial to emphasize the environmental and economic benefits of EMs. These insights provide a foundation for promoting sustainable transportation in underdeveloped areas, contributing to environmental preservation and economic development.

THE VOLCANOSTRATIGRAPHY OF THE GEOTHERMAL AREA OF MOUNT UNGARAN, CENTRAL JAVA

Febrianto Mangopo, Suryantini Suryantini — Tue, 21 Jan 2025 00:00:00 +0800

The Ungaran Geothermal Working Area (WKP) is located in Central Java Province where it is one of the ancient volcanoes with a composite type. In the geothermal exploration stage, it is important to determine the boundaries of volcanic rocks by the interpretation of remote sensing data. This research is to create a volcanostratigraphic unit using ASTER DEM data to create a digital elevation model. This data will be used to create a volcanostratigraphic unit with an explanation of the ridges and rivers that will point to the center of the eruption. The geological history of Java Island is a complex arrangement of basin formations, faults, folds, and volcanism under the influence of different pressure regimes from time to time. Java Island is in the subduction zone, a collision between the Indo-Australian Plate and the Eurasian Plate. The history of Javanese subduction is also the history of magmatism paths that have formed over time, forming a pattern of magmatism that is rich in igneous and volcanic rock formations. The geological structure in the Mount Ungaran area is controlled by a collapse structure that extends from west to southeast of Mount Ungaran. The volcanostratigraphic method is used using the source of the eruption center that can still be identified, for example, the existence of circular features and the morphological shape of the volcanic cone that is clear in satellite images. The sources of the eruption centers that can be identified are closely related to the relatively young age, generally in the Quaternary Period. On the regional scale of the Mount Ungaran WKP with a scale map of 1:100,000, three Brigades were identified around the Mount Ungaran WKP, namely Sumbing Brigade which is on the southwest side consisting of Sumbing Crown and Sindoro Crown. Based on the 1:50,000 scale map on the Ungaran WKP, it was identified into 2 Crown (Main Eruption Center), namely Young Ungaran Crown (Kh. Ung. Muda) and Kuluk Old Ungaran Crown (Kh.Ung. Tua) on the scale map of 1:50,000 identified 5 volcanostratigraphic units as Hummock originating from the central eruption and eruptions including Pengion Hummock (Gm. Pgn), Songo Hummock (Gm.Sgo), Godong Hummock (Gm. Gdg), Tungku Hummock (Gm. Tgk) and Kaligesik Hummock (Gm. kgk).

Identification of Potential Prospect Areas Based on Gravity Data Analysis for Danau Ranau Geothermal Working Area

Bimo Ario Putra, Suryantini Suryantini — Mon, 20 Jan 2025 00:00:00 +0800

Danau Ranau Geothermal Working Area (WKP) is geographically located in the southwestern part of the island of Sumatra, precisely in the border area between South Sumatra Province and Lampung Province. This area is influenced by the Great Sumatra Fault and is the intersection of the Komering Segment to the north and the Semangko Segment to the south. The Lake Ranau Geothermal Field is one of the WKP that is still in the exploration phase and there are no drilling wells or temperature gradient well. The main purpose of exploration is to determine the drilling location. The criterion for the success of the drilling target is an area that has high temperature and permeability. Temperature is associated with the existence of a heat source, while permeability is related to the existence of geological structures, both faults and sturdy structures filled with fluids that can be a media for heat energy transfer and are the target of this study. To obtain this information, this study was conducted using gravity data analysis with First Horizontal Derivative (FHD), and Euler Deconvolution analysis, to determine the structure below the surface to identify permeable zones, in order to help in the construction of geothermal system and the delineation of area prospects.

Adaptive Protection Scheme in Distribution Networks

Mon, 20 Jan 2025 00:00:00 +0800

The protection system is comprehensive in scope, and it is essential to maintain continuity of service. The 20 kV distribution network in Indonesia only uses a conventional protection system, so due to the renewal of the power flow configuration to multisource, the protection system needs to be evaluated. This research was conducted by comparing different scenarios using the IEEE 33-bus test system. This test is used to determine the most effective coordination scheme used in 20 kV distribution networks with and without distribution generations (DG). This will determine the type of relay, current and time multiple setting (TMS) of the relay pickup to avoid symphatetic trip and protection blinding. The benefits of the proposed tests and results are that they improve the selectivity and effectiveness of relays despite changing system conditions.

Enhancing Understanding of Project Valuation of Energy Transition through Hybrid Power Plants

Ahmad Barlianta, Fathiro Hutama Reksa Putra — Mon, 20 Jan 2025 00:00:00 +0800

Hybrid power plants, which combine renewable energy sources such as photovoltaic solar and wind power with storage systems, offer a promising solution for improving energy reliability, reducing emissions, and accelerating the energy transition. However, their development is complex due to the integration of multiple energy sources, grid parity challenges, and the variety of potential risks involved. Therefore, this type of power plant requires a project valuation approach that addresses beyond techno-economic aspects such as risks and uncertainties due to intermittent conditions. This study explores and examines best practices and current insights into project valuation approaches for hybrid power plants, while also highlighting gaps in existing research and future research direction. The analysis reveals that most research primarily focuses on deterministic approaches of economic analyses, which have been predominantly used in the field. A deterministic approach provides a single specific value of economic estimation. However, we found that recent studies have highlighted the limitation of such approach in incorporating uncertainties and risks. Therefore, our findings suggest the need for further research to incorporate uncertainties and to adopt models such as stochastic approaches that better reflect the spectrum of potential outcomes.

Design and Numerical Study of Hydrokinetic Turbines at Bakaru Hydropower Tail Race for the Application of Combined-Cycle Hydropower Systems

Muhammad Ramadhan, I Nengah Diasta, Gea Fardias Mu’min — Mon, 20 Jan 2025 00:00:00 +0800

The Net Zero Emission (NZE) target for 2060 has driven countries to increase the number of renewable energy power plants. In addition to building new renewable power plants, there is also an effort to enhance the capacity or optimize existing renewable power plants. One such optimization is the utilization of kinetic energy in the tail race of HEPP, which can be harnessed to generate electricity by installing a hydrokinetic turbine. The electricity generated from the tail race can be fed into the grid for network consumption or used to power auxiliary equipment at the hydroelectric plant. This reduces the selfconsumption (PS) of the plant, a concept known as Combined-Cycle Hydropower Systems. Bakaru Hydro Electric Power Plant (HEPP) is a run-ofriver hydroelectric power plant equipped with Francis vertical turbines, located in Bakaru Village, Lembang District, South Sulawesi. flow speed measurements of the tail race at Bakaru HEPP, using an Acoustic Doppler Current Profiler (ADCP), showed flow speeds ranging from 1.6 m/s to 2.4 m/s during maximum load conditions of 126 MW. Therefore, the theoretical power that can be generated by the hydrokinetic turbine is approximately 48 kW. It is important to determine the optimal placement of the turbine to maximize the utilization of water flow in the tail race and minimize the impact caused by the turbine installation. Therefore, this study designs three turbines with different blade
lengths based on solidity (0.1, 0.2, and 0.3). The chord variation is 100 mm, 209 mm, and 314 mm, and simulates their placement in two different positions in the tailrace to analyze the effect on the performance of the hydrokinetic turbine.

Audible Noise FromAmorphous Metal and Silicon Steel-Based Transformer Core

Lathif Nur Mucharam, Suwarno Suwarno — Tue, 21 Jan 2025 00:00:00 +0800

Power transformers are the main components in the electric power system that function as voltage converters in the distribution of electrical energy. With complaints from the public about noise in amorphous transformers that cause fear in the community. The reliability of distribution transformers is significantly improved with a well-written test plan, which must include specifications for
transformer testing. On newly manufactured distribution transformers, testing is carried out to determine whether the reliability of the distribution transformer meets reliability standards. The test carried out is a core noise test to determine the noise in amorphous transformers. Testing is carried out at the factory with 2 methods, namely no load test and load loss test. For field measurements using the load loss test method. Testing carried out at the factory and field measurements obtained high noise in amorphous type transformers. This study is to determine the noise that occurs in amorphous transformers whether the noise is still safe for the environment and the community.

Investigating the Causes of Production Decline in ULB-02 Well, Ulumbu Geothermal Field: A Combined Decline Curve Analysis and Reservoir Scaling Simulation Approach

Desto Novianto, Sutopo Sutopo, Ali Ashat, Danu Sito Purnomo — Mon, 20 Jan 2025 00:00:00 +0800

This study examines the declining steam production at the Ulumbu Geothermal Power Plant in East Nusa Tenggara, Indonesia, focusing on the ULB-02 well from 2015 to 2023. Initially, a 5% annual decline in steam output was expected; however, recent data indicates an accelerated decline, likely due to scaling within the wellbore. Scaling reduces steam flow and well productivity, contributing to a significant decrease in wellhead pressure (WHP) and steam flow rate. Decline curve analysis (DCA) shows an exponential decrease in steam output, with projections indicating a reduction to about 12.5 kg/s by 2030, corresponding to a drop in power generation capacity to around 5 MW. To assess the impact of scaling, the study uses TOUGHREACT simulations to model mineral deposition and its effect on wellbore permeability. The results confirm that scaling is a primary factor in the well's declining performance. The study highlights the importance of reservoir management and scaling mitigation strategies to ensure the long-term sustainability of the Ulumbu plant. Recommendations include monitoring wellhead pressure, addressing scaling issues, and implementing periodic interventions to optimize well performance and prevent further output decline. These findings are relevant to other geothermal fields with similar challenges.

Coal Blending Effect in Coal Fired Power Plant Performance

Fransiskus Xaverius Adeodatus Alfa Febriant, Willy Adriansyah, Mochamad Soleh — Mon, 20 Jan 2025 00:00:00 +0800

Coal is one of most favorable energy source due to its high calorific value and easily processed. In 2022 until 2024, coal price rose significantly, leading to energy crisis because some CFPP need to stop operating due to lack of coal supply, especially CFPP with high rank coal as its primary fuel designed. Coal blending with LRC is one of best method to maintain CFPP sustainability in the middle of coal crisis. A simulation using GateCycle as a tool is conducted to study change of boiler operating parameter and boiler performance while using coal blending method in 100 MW Ombilin CFPP. From the simulation and study, increased LRC composition will result in increasing of coal flow by 0.253 t/h for every 1% LRC composition and FDF electrical load by 18.48% due to increased combustion air flow. Boiler efficiency also reduced from 91.94 %to 86.20% due to high moisture content. With maximum mill capacity as its constraint, in order to produce 100 MW, maximum allowable LRC composition of coal blending in Ombilin CFPP is 37%.

Development of Electrification Planning Method with Renewable Energy Technology: Case Study in Central Sulawesi

Nuriy Zulfah Zakiyyah, Joko Siswanto — Mon, 20 Jan 2025 00:00:00 +0800

The equal distribution of electricity facilities is also encouraged by the Indonesian government, one of which is through the creation of an electrification roadmap for unelectrified villages. This roadmap must align with the government's commitment to the Net Zero Emission target, so the chosen power plants must use Renewable Energy (RE). PT PLN (Persero), as the state-owned company responsible for electrification, does not yet have a standard method for selecting RE technology. Central Sulawesi, with its diverse geography from mountains to islands, presents its own challenges for interconnection with the South and West Sulawesi or North Sulawesi and Gorontalo electrical systems. A case study in unelectrified areas of Central Sulawesi was conducted to determine the dimensions and indicators for selecting RE technology and developing an electrification planning method.

Feature Selection for Predictive Asset Health Management in Power Plants Using Random Forest

Muhammad Ghafur Abdulah Winata Santana, Mochamad Ikbal Arifyanto — Mon, 20 Jan 2025 00:00:00 +0800

In the power generation industry, effective asset health management is essential for optimizing maintenance strategies and preventing costly failures. This study focuses on feature selection for predictive asset health management using the Random Forest algorithm, applied to PLN Indonesia Power's power plant assets. A dataset of 64,999 entries containing asset criticality metrics such as Maintenance Priority Index (MPI), Asset Criticality Ranking (ACR), and other relevant features was analyzed. Using Recursive Feature Elimination (RFE), MPI, ACR, and ACRRANK were identified as the most significant predictors of asset health. The model achieved an accuracy of 93.64%, demonstrating the importance of feature selection in improving prediction performance. This research provides valuable insights into optimizing maintenance efforts through targeted data-driven predictions.

Density Functional Analysis of Copper Doping Effects on the OER Activity of Nickel-Iron Phosphate

Rizky Dio Idhola, Ahmad Nuruddin, Adhitya Gandaryus Saputro — Mon, 20 Jan 2025 00:00:00 +0800

This study explores the impact of Cu doping on the oxygen evolution reaction (OER) activity of bimetallic NiFe phosphate using density functional theory-based calculations. The results indicate that Cu doping improves the catalytic performance at the Fe site by lowering the overpotential, while slightly increasing it at the Ni site. The Cu site, however, shows poor OER activity due to weak intermediate binding.

Design and Optimization of Hybrid Power Plants (Solar PV and Diesel Generators) for Remote Areas in the UID Kalselteng Region: A Case Study of Kerasian Island

Ahmad Syairozie, Poetro Lebdo Sambegoro, Muhammad Joharifin — Mon, 20 Jan 2025 00:00:00 +0800

This study investigates the operational performance and economic feasibility of a hybrid renewable energy system implemented on Kerasian Island, located in Kotabaru Regency, a remote off-grid area. The system integrates photovoltaic (PV) panels, a battery energy storage system (BESS), and a diesel generator (DG). Using HOMER Pro software, six different scenarios were analyzed to optimize the PV panel size and battery storage capacity, with the objective of minimizing the levelized cost of electricity (LCOE) while ensuring
the system meets the required energy demand. The results demonstrate that the hybrid system, with PV panels accounting for 90,6% of the daily energy consumption, yields the lowest LCOE of Rp 3.522,21 per kWh. Compared to a diesel-only system, the hybrid configuration significantly reduces CO₂ emissions, thereby decreasing dependency on fossil fuels. While the initial investment in
battery storage is relatively high, the hybrid system proves to be cost-effective in the long term, providing reductions in operational costs and diesel consumption. The PV-BESS-DG system represents a sustainable and economically viable energy solution for off-grid regions, with the potential for considerable reductions in CO₂ emissions.

Effect of Hole Transport Layer Acceptor Density on the Performance of FASnI3 Perovskite Solar Cells

Mon, 20 Jan 2025 00:00:00 +0800

Lead-free perovskites have emerged as a highly promising alternative for efficient and environmentally friendly photovoltaics due to their inherent optoelectronic properties. This study presents a numerical investigation into structured n–i–p inorganic perovskite photovoltaics using the Solar Cell Capacitance Simulator (SCAPS-1D). Various carbon materials including single-walled carbon nanotubes (SWCNT), graphene oxide (GO), and reduced graphene oxide (rGO) were employed as candidates for the hole transport layer (HTL) with FASnI₃ serving as the active material and TiO₂ as the electron transport layer (ETL). This study investigates the impact of acceptor density on the performance of perovskite solar cells (PSCs) using various hole transport layers (HTLs), specifically SWCNT, GO, and rGO. The results indicate that increasing the acceptor density of particular HTL enhances the power conversion efficiency (PCE), in which GO shows a PCE increase from 17.99% to 19.61% as the acceptor density rises from NA=10¹⁵ cm⁻³ to NA =10²² cm⁻³ while SWCNT and rGO do not. This study emphasizes the critical role of acceptor density in optimizing PSC performance and its significance for future research and the development of advanced HTL materials.

Study of Acid Zone Delineation in Mataloko Geothermal Field using The Total Conductance Method

Ivan Darmawan, Suryantini Suryantini — Mon, 20 Jan 2025 00:00:00 +0800

Mataloko geothermal field in Ngada Regency, East Nusa Tenggara, is one of the geothermal field in eastern Indonesia that has been in production but has now stopped production. Several hot spring manifestations in the Mataloko are acidic, for example in Wae Luja Hot Stream with pH 2,92 and Wogoalo Hotpool 2 with pH 4. The Mataloko geological logging data also shows that all 5 wells drilled vertically around the fumarole area, have almost the same elevation, contain acidic alunite minerals (pH <4) at a depth of 300-350 m. The gas composition in NCGs, informs that the H₂S gas content in the MT-4 well is relatively greater compared to other wells. This indicates that the MT-4 well fluid is slightly acidic. Research is needed to mitigate by creating a map of the estimated distribution of acidic fluid areas. The proposed solution to the problem is to create a map of areas that have acid content in the Mataloko geothermal field using the Total Conductance method with an electrical conductivity approach. From the results of the calculation of the Total Conductance value, the acid zone in the Mataloko geothermal field has a value of ±700 Mhos.

Optimization Of Frequency Stability for a 10 MW OnGrid Solar System in the Electricity System Of Nusantara Capital City

Didik Darmawan, Poetro Lebdo Sambegoro, Agustriadi Agustriadi — Mon, 20 Jan 2025 00:00:00 +0800

The Increasing demand for electrical energy and global warming are driving the use of renewable energy. Environmental issues regarding increased air pollution emissions due to various human activities that cause climate change are in the global spotlight. Solar energy as a form of renewable energy is abundant, clean and free. However, the addition of solar power plants into the electricity system does not always have a positive impact due to its intermittent nature and dependence on unruly primary energy. In the electricity system of Ibukota Nusantara, a 10 MW solar power plant is connected On Grid and synchronized with the Mahakam System via 20 KV. The performance of PLTS is highly dependent on solar radiation and weather. This causes the PLTS output power to always fluctuate. PLTS fluctuations will be dampened by the battery so as not to unduly affect the performance of other plants. This simulation will use DigSILENT 15.1 software. In this simulation, several case studies are carried out, namely the effect of PLTS integration on system frequency, PLTS penetration on system stability, the effect of loading on free governor and hybrid simulation with batteries for system stability. So that this simulation is able to determine the limit of system stability when this PLTS has operated up to 50 MW with this optimal capacity certainly does not interfere with the stability of the system frequency.

Microplastics as Emerging Vectors of Climate Change: A Critical Review of Impacts, Interactions, and Research Gaps

Badrun Ahmad, Indah Rachmatiah Siti Salami — Tue, 21 Jan 2025 00:00:00 +0800

This critical review synthesizes current knowledge on the emerging role of microplastics as vehicles for pollutants and pathogens, particularly within the context of a changing climate. Climate change exacerbates the environmental impacts of microplastics by intensifying their interactions with biological systems. Biofilms colonizing microplastic surfaces facilitate the co-adsorption of pathogens and pollutants, creating localized hotspots of contamination with significant implications for aquatic organisms and potentially human health. The presence of heavy metals and organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), can exert selective pressures on microbial communities within these biofilms, leading to the enrichment of virulent or metal-resistant strains. Moreover, pollutants can provide a protective environment for pathogens, enhancing their survival and persistence in ecosystems already stressed by climate change. This review highlights critical research gaps, including the long-term effects of microplastic-associated pollutants on biota and the mechanisms by which climate change influences these complex interactions. Addressing these knowledge gaps is crucial for developing effective management strategies to mitigate the risks posed by microplastics and safeguard both environmental and human health in a changing climate.

Optimization of Nusa Penida Electrical System: A Simulation Approach for Cost and Emission Reduction

Mikhael Vidi Santoso, Kevin Marojahan Banjar-Nahor, Nanang Hariyanto — Mon, 20 Jan 2025 00:00:00 +0800

Nusa Penida is one of Indonesia's outer islands, territorially part of Bali Province. The electrical system in this area is separate from Bali's electrical grid and is supplied by a 20 kV interconnection from a hybrid solar-wind-diesel power station, which connects Nusa Penida, Nusa Lembongan, and Nusa Ceningan islands. This system is referred to as the "Three Nusa System." The average solar radiation is 5.34 kWh/m²/day with an average wind speed of 4.4 m/s. These conditions can be utilized to develop renewable energy generation in the region. However, environmental conditions greatly affect the system's performance in meeting electricity supply demands. This paper discusses the feasibility of the hybrid power plant established under the natural conditions and the equipment specifications used in the hybrid system in Nusa Penida, taking into account economic factors and the emissions produced. The expected outcome is to determine how the lowest LCOE can be achieved, as well as emission reduction factors, to create the most optimal electrical system structure.

Factors Influencing Electric Vehicle Adoptions: A Literature Review Based on the UTAUT2 Model

Aisyah Pratiwi, Aldila Rizkiana, Hasrini Sari — Mon, 20 Jan 2025 00:00:00 +0800

The global climate crisis has become a severe issue that impacts all facets of human existence. Over half of the world's CO2 emissions are caused by the transportation sector, with road transport contributing roughly one-sixth of all emissions. In order to lessen the sector's negative environmental effects, it is crucial to create a clean and sustainable transportation system. As an alternative
to internal combustion engines (ICE), Electric Vehicles (EVs) are becoming more and more popular. They are thought to lessen reliance on energy imports. However, there are a number of obstacles to overcome before transportation electrification can be fully implemented globally, including those related to infrastructure, technology, economy, and user acceptance. The Indonesian
government has bolstered its support for EV adoption through policies and laws, including lowering tax incentives and subsidies and building charging infrastructure, in keeping with its pledge to cut Greenhouse Gas emissions (GHG) emissions by 2030. Customers' trust also influences the adoption of EVs in technology since they frequently have concerns about its sustainability, safety, and
performance. This study combines technology trust and incentive policy satisfaction and applies the Unified Theory of Technology Acceptance and Use 2 (UTAUT2) to examine the variables impacting EV adoption. This model was created to elucidate the variables that may impact consumers' choices to switch to EVs for daily transportation.

Subsurface Temperature of Well B-02 and D-01 Tulehu Geothermal Field: Past and Present

Risman Chandra Budiman, Suryantini Suryantini, Tony Widiatmoro — Mon, 20 Jan 2025 00:00:00 +0800

Abstract. Tulehu geothermal field is one of the geothermal potentials in Eastern Indonesia. This field is located in the eastern part of Ambon Island and is associated with a relatively old geothermal system, where the last volcanic activity is estimated to have occurred during the Pliocene. The subsurface temperatures of wells B-02 and D-01 were analyzed using drilling data, including well lithology data based on cutting analysis, laboratory analysis such as petrography, XRD, and fluid inclusion, as well as temperature and pressure measurements (PT Logging). The subsurface temperature of well D-01 shows a significant decrease, approximately 60-70°C, compared to its formation temperature in the past. Meanwhile, in well B-02, the current temperature is similar to its formation temperature based on fluid inclusion analysis, though the current temperature is slightly lower than its formation temperature when assessed through alteration mineral temperature analysis.

Prediction of Lightning Strikes Electrical Transmission Lines Using Machine Learning Approaches

Tue, 21 Jan 2025 00:00:00 +0800

This study evaluates and compares the performance of three Machine Learning models—RNN, LSTM, and Transformer—for forecasting lightning strikes that can disrupt transmission towers along the 150 kV Bukit Asam - Baturaja line. Using historical lightning data from 2018 to 2024, the models were trained and validated, with the Transformer model demonstrating superior predictive accuracy. The Transformer achieved a high R-squared value of 0.9543, significantly outperforming RNN and LSTM models. Results indicate that the Transformer model's self-attention mechanism effectively captures long-term dependencies and patterns, making it a reliable choice for forecasting. However, the study is limited to this specific region and dataset, highlighting the need for future research to incorporate additional variables, such as meteorological and geographical factors, for improved adaptability. The findings underscore the importance of accurate and efficient forecasting models to support proactive measures and mitigate lightning-induced disturbances on transmission infrastructure.chnology for risk mitigation in electrical transmission networks.

Development of a Framework for Determining Business Process Indicators as a Basis for Risk Identification at PT PLN (Persero)

Fadhil Aswin Pradipta, Budhi Prihartono — Mon, 20 Jan 2025 00:00:00 +0800

PLN has established long-term objectives detailed in the Rencana Usaha Penyediaan Tenaga Listrik (RUPTL), or Electricity Supply Business Plan, for 2021-2030. This plan focuses on providing an adequate, reliable, and efficient electricity supply to ensure national energy security. However, significant uncertainties may present risks that threaten the achievement of PLN's strategic goals and business processes, potentially disrupting the company's business sustainability. To mitigate these risks, PLN has implemented risk management practices and business process standardization, with policies that include mandatory risk identification in business processes. Process Performance Indicators (PPIs) are measurable values used to demonstrate the effectiveness of a process. In practice, the formulation of PPIs at PLN has not been optimally implemented due to the absence of specific steps on how to determine PPIs. Therefore, this study aims to contribute both scientifically and to meet PLN's practical needs. Through a literature review and obvservation, this study will examine the relationship between organizational strategy, Key Performance Indicators (KPIs), business processes, and risk management. This study identifies the relationship between strategic objectives, Key Performance Indicators (KPIs), business processes, Process Performance Indicators (PPIs), and risk identification. The findings emphasize the importance of integrating these elements to ensure that every business process not only aligns with the company's strategic objectives but also effectively identifies, manages, and mitigates risks that could potentially hinder goal achievement. The results of this study are expected to serve as a guideline for PT PLN (Persero) in implementing PPIs as tools that not only monitor operational performance but also strengthen proactive risk management. Through this approach, PPIs can be optimized to support corporate performance
achievement, ensure operational sustainability, and uphold good governance at every level of the business process executed

A Synthesis and Characterization of Silica Nanoparticle-Based Nanofluid from Geothermal Mud for Solar Panel Cooling Material

Mon, 20 Jan 2025 00:00:00 +0800

Silica nanoparticles are an essential nanofluid ingredient for absorbing heat in photovoltaic systems. Silica powder is extracted from geothermal sludge using the sol-gel method with acid-base treatment. The gel formed is stored at 12 and 18 h aging to control the particle size and microstructure. XRD, FTIR, SEM, TEM and BET were employed to characterize the resulting silica particles' microstructure, morphology and surface area. It is found that the silica nanoparticle contains a crystalline phase microstructure, with an average particle size of 40 nm, embedded in an amorphous matrix. The resulting silica nanoparticles meet the requirements and are suitable for forming nanofluids.

Exploration and Analysis of Resilience Engineering Factors in Electricity Distribution Organization

Gevi Hanindya Putra Bachtiar, Yassierli Yassierli, Ari Widyanti — Mon, 20 Jan 2025 00:00:00 +0800

The electricity distribution sector is known for its high risk and complex sociotechnical system. PT PLN (Persero), electricity company in Indonesia, reported that 75% of work-related accidents happened in its distribution sector. It can be reasonably assumed that the safety-I approach is incapable of reducing the number of accidents. Resilience engineering (RE) then emerged as a part of a
modern approach called safety-II in occupational health and safety management. This study aims to explore RE dimensions that affect resilience potential in the distribution sector of PT PLN (Persero) and determine critical area that need improvement for achieving zero accident. Questionnaire of 100 technical service officers in Unit Induk Distribusi Jakarta Raya were collected and analyzed using
principal component analysis (PCA) and importance-performance analysis (IPA). This study makes scientific contribution by generating seven novel dimensions of RE specifically tailored to the electricity distribution organization. These dimensions (% variance) are risk management (30,51%), collaborative culture (12,42%), safety commitment (6,28%), adaptive decision-making (5,71%),
incident readiness (4,49%), continuous learning (4,00%), and personnel competency (3,89%) with total of 67,29% variance explained. After being classified in the IPA matrix, it was identified that priorities on personnel competency, collaborative culture, and continuous learning should be placed to enhance resilience potential.

Techno-Economic Analysis of PV and BESS for Residential Loads

Hardian Yanuar Wibowo, Burhanuddin Halimi — Mon, 20 Jan 2025 00:00:00 +0800

Energy sustainability is a critical issue, particularly in residential areas where renewable energy sources, such as solar photovoltaic (PV) systems, are becoming increasingly integrated. Battery Energy Storage Systems (BESS) play a pivotal role in optimizing energy utilization, balancing supply and demand, and reducing reliance on the power grid. This research contributes to the field of sustainable energy management by providing a detailed analysis of energy flow, battery performance, and degradation in a residential PV-BESS setup, introducing a comprehensive financial analysis, including Net Present Value (NPV), Internal Rate of Return (IRR), Return on Investment (ROI), and Payback Period, to assess the feasibility of BESS deployment, highlighting the impact of current tariff regulations on the financial outcomes of residential energy storage systems, offering practical recommendations for optimizing battery usage to balance energy demand and supply while preserving battery health, and scalability tha propose a scalable model for integrating PV-BESS systems in residential areas, contributing to broader renewable energy adoption and grid stability. The findings of this research conclude that, based on the load conditions in this study, a BESS with a capacity below 500 kWh can be a viable investment option for utilities, offering both technical and economic benefits. However, when considering unmet demand, the best choice is a BESS with a capacity of 350 kWh.

Employee Mutation Map for PLN Employee Placement Using Machine Learning

Mon, 20 Jan 2025 00:00:00 +0800

This research aims to develop an employee transfer mapping system for PLN employee placement using a machine learning approach, specifically K-means clustering. The dataset used includes internal PLN data such as employee job history, asset distribution, operational performance, as well as external data from BPS (Badan Pusat Statistik) that includes regional characteristics, demographics, and infrastructure [1][2]. The data preprocessing process involves handling missing values, normalizing numerical features, and encoding categorical features to ensure data quality and consistency [3][4]. The K-means algorithm is applied to cluster units into categories such as Technical (TEK), Marketing (SAR), and Energy Transaction (TEL) based on selected features [5][6]. After clustering, each unit is given a unique identification that describes the characteristics of the cluster and region [7]. The clustering and identification results are
visualized using Convex Hull and PCA in two-dimensional (2D) and three-dimensional (3D) formats [8][9], demonstrating a clear separation of categories and subcategories within PLN units. Therefore, the results of this research show that the use of clustering can effectively support decision-making processes related to employee placement [10].

A Review of Biomass Cofiring As An Effort for Maintaining Steam Power Plant Performance In Indonesia

Yoga Dwi Widagdo, Prihadi Setyo Darmanto — Mon, 20 Jan 2025 00:00:00 +0800

Nowadays, fossil fuel like coal, oil, and natural gas represents primary energy resources in the world. However, the depletion of fossil fuel reserves and human population growth contrast with human energy needs. It also created more environmental problems such as global warming and high carbon emissions. Biomass is one of the earliest sources of energy with speciﬁc properties. It can be converted into any other form of fuel but needs special treatment. Co-firing biomass with coal can provide a range of opportunities, such as reducing fuel costs for some companies and minimizing greenhouse gas emissions to protect the environment. In this review, several aspects which are associated with cofiring biomass in boilers have been investigated such as the effect after using biomass to equipment performance, exhaust gas emissions, and any other problem like slagging or fouling in boiler caused by biomass, what we can do to improve biomass quality in the future to implemented high percentage cofiring. From this review, we want to show what the best way Biomass cofiring for maintaining Steam Power Plant performance in biomass cofiring in Indonesia such as Pellet Biomass. There are more than 85 million ton / year pellet potential in Indonesia with some power plant already using biomass to cofired with coal more than 29 thousand ton per year in East Indonesia Region power plant. The future of biomass in Indonesia depends upon the development of the markets for fossil fuels and on policy decisions regarding the biomass including the premium price of biomass, the ability to establish stable feedstock supply chains, and a range of technical challenges.

Spare Part Selection for Storage in PLN Suku Cadang Warehouse Using Clustering Analysis

Tue, 21 Jan 2025 00:00:00 +0800

PLN Suku Cadang (PLNSC) faces challenges in determining which spare parts should be stored in warehouses to support power plant operations. This study employs the k-Means clustering method to analyze historical data, in-cluding demand frequency, lead time, quantity, and cost. Using this method, spare parts are grouped into several clusters to identify storage priorities. The clustering results are further validated using specific criteria: high demand frequency, low lead time, high quantity, and low cost. This study demon-strates that the clustering method can help optimize inventory management, reduce downtime risks, and improve cost efficiency in storage.

Sustainable Waterfront Development approach for Revitalization of Settlements in Heritage Area (Study Case: Kampung Arab Al-Munawar, Palembang)

Ananda Amelia Pandani, Woerjantari Kartidjo, Erika Yuni Astuti — Mon, 20 Jan 2025 00:00:00 +0800

The waterfront area of Palembang City is a cultural heritage area and is a strategic area whose development is prioritized. The Musi River, as a transportation route and entrance to trade, has resulted in the formation of ethnic migrant settlements on the banks of the river, one of which is ethnic Arabs. Kampung Arab Al-Munawar area is one of the oldest Arab villages located on the banks of the Musi river which has eight cultural heritage buildings. However, unfortunately this Arab village is faced with problems of residential density, informal buildings which cause slums, areas prone to flooding, lack of green open space, inadequate facilities and infrastructure which causes poor environmental quality and has an impact on reducing the quality of life. community. The aim of this research is to determine efforts to improve the quality of the physical and non-physical environment (social and economic) using a Sustainable Waterfront Development approach.

Working Fluid Selection in Organic Rankine Cycle (ORC) with Flue Gas Heat Utilization

Marlina Ayu Lestari, Ari Darmawan Pasek — Mon, 20 Jan 2025 00:00:00 +0800

There are many potential sources of excess heat that have not been utilized, the ORC system offers a solution to utilize this energy, thereby increasing overall energy efficiency. Highlighting the advantages of the ORC system, including its ability to operate at lower temperatures, utilize a variety of working fluids, and utilize heat efficiently from various sources. describing the methodical process of choosing the best and most suitable working fluid, including the types of working fluids, how they affect system performance, and the standards for choosing the best working fluid based on physical and thermodynamic characteristics. Furthermore, emphasis is placed on environmental effects, safety considerations, and the kind of heat source that will be used. The use of exhaust gas heat will be the main topic of this essay from PLTMG engines according to the author's research.

DFT Studies of NH3 Adsorption on Graphene-Supported NixMy (M=Pt and Rh; x=2–6; y=0–4)

Alfani Yusuf, Adhitya Gandaryus Saputro, Muhammad Haris Mahyuddin — Mon, 20 Jan 2025 00:00:00 +0800

This study investigates the adsorption of ammonia (NH₃) on bimetallic Ni_xM_y-G (M = Pt, Rh; x = 2-6, y = 0-4) clusters supported on graphene using Density Functional Theory (DFT) calculations. The primary goal is to understand the structural stability and adsorption characteristics of these bimetallic clusters as potential catalysts for NH₃ decomposition, which plays a crucial role in hydrogen production. The results show that the substitution of nickel (Ni) atoms with platinum (Pt) or rhodium (Rh) improves the structural stability of the catalyst clusters, with Rh-based clusters showing greater stability than Pt-based ones. Furthermore, NH₃ adsorption tends to occur predominantly on Pt atoms in the Ni_xPt_y clusters and on Ni atoms in the Ni_xRh_y clusters. The strongest adsorption is observed in Ni₄Pt₂-G, indicating its high potential as a catalyst. Overall, the incorporation of Pt and Rh into Ni clusters enhances both stability and adsorption properties, positioning these bimetallic systems as promising candidates for further exploration in catalytic ammonia decomposition.

Geothermal Resource Estimation of Ulubelu Area Based on Volcanostratigraphic Studies

Phillip Albert Mogi, Muhammad Rizky Ramdhani Iman, Tony Rahadinata — Mon, 20 Jan 2025 00:00:00 +0800

The Ulubelu Geothermal Area is one of the Geothermal Working Area owned by PT. Pertamina Geothermal Energy (PGE) located in Tanggamus Regency, Lampung Province. To determine the geothermal potential of the Ulubelu area, a scientific study is needed to explain the relationship between volcanism in the Ulubelu area and the formation of the geothermal system in that region. The topographic maps at the scales of 1:100,000 and 1: 50,000. The study focues on determining Ulubelu’s volcanic characteristic parameters, which included volume as primary data and geological structure patterns, volcanic age, and magma evolution as secondary data. The Randingan caldera I Ulubelu has a volcanic volume of 120km³, indicating a sufficiently large magma chamber as heat source (Q=1.9x10^15J). The youngest volcanism is 200,000 years old, which falls within the ideal age range forming a mature geothermal system. The geological structure pattern is homogenous, with radial vent distribution is going towards the Randingan dome’s top. Given these characteristics, it is reasonable to assume that the Ulubelu Geothermal Area has promising geothermal prospects for exploration and development.

A Comprehensive Review of Ammonia Co-firing in Steam Turbine Power Plants: Challenges and Opportunities

Anggi Riyo Prambudi, Firman Bagja Juangsa — Mon, 20 Jan 2025 00:00:00 +0800

Hydrogen is a clean energy carrier with abundant availability but requires appropriate storage methods due to its low volumetric density in gaseous form. Ammonia is a promising hydrogen carrier because of its high volumetric density, ease of long-term storage, and well-established production infrastructure. Additionally, ammonia can be synthesized using renewable energy sources. As a
substitute for fossil fuels, ammonia offers the advantage of being a carbon-free fuel, making it highly suitable for decarbonization initiatives currently undertaken by governments worldwide. Ammonia is typically used as a fuel in a co-firing scheme, which combines it with other fuels. Co-firing ammonia with coal in power plants is a cost-effective solution, as it leverages existing infrastructure to reduce carbon emissions by decreasing coal usage without significant investment costs. However, while the performance of co-firing ammonia combustion is comparable to pure coal combustion, the increase in NOx emissions requires careful mitigation. Proven methods, such as air staging and secondary fuel injection, can reduce NOx emission levels in flue gas while maintaining combustion stability. In this paper, the terms ammonia and NH3 are used interchangeably.

Effect of NIP and PIN Architectures on the Performance of FASnI3 Perovskite Solar Cells

Mon, 20 Jan 2025 00:00:00 +0800

This study explore the impact of NIP and PIN architectures on the performance of FASnI₃-based perovskite solar cells (PSCs) through simulations using the SCAPS-1D software. FASnI₃ is a promising material for PSCs due to its
suitable bandgap, better thermal stability, and lower toxicity compared to Pb-based perovskites. The optimization of the NIP structure involves variations in donor density and the thickness of the FASnI₃ layer. A donor density in the form of a
shallow density acceptor of 10¹⁷ cm⁻³ leads to optimal performance improvement. Comparisons between NIP and PIN configurations show that although the NIP architecture outperforms PIN with Spiro-OMeTAD as hotel transport layer (HTL) material, the choice of HTL significantly affects the efficiency of the PIN architecture. PTAA is identified as the best HTL for the PIN structure, offering higher efficiency. Additionally, the study also investigates the optimization of the
capture cross-section value to 10⁻¹⁹, resulting in maximum solar cell performance for all HTL material options. The efficiencies of solar cells with HTL materials PTAA, PEDOT:PSS, and Spiro-OMeTAD are 22.54%, 16.78%, and 4.58%,
respectively, with Au electrodes.

Advanced Air Mobility Electric Vertical Take-off Landing Aircraft Configuration and Concept Design Generation and Evaluation

Mon, 20 Jan 2025 00:00:00 +0800

In the modern day, Advanced Air Mobility, including electric vertical take-off landing (eVTOL) aircraft, is getting traction. However, not all possible configurations are modelled and compared to each other. A structured generation method is proposed in this study, by combining building blocks as well as parametric sizing. The proposed method in this paper can model multicopter, vectored thrust, independent thrust, and combined thrust configurations. Combined thrust is a configuration that has not been explored in other studies. The proposed method also allowed more combinations of alternatives by varying the number of rotors, which are fairly limited in other studies. Seventeen alternative configurations are generated and evaluated. The generated alternatives are evaluated by performing aerodynamic, power, energy, and weight analysis. The results of the analysis will be then compared to the requirements. The method proposed in this paper can analyze the differences between each configuration.

Critical Contingency Assessment of a 150/275 kV Interconnected Power System

Fajar Khairuddin Kurniawan, Kevin Marojahan Banjar Nahor, Nanang Hariyanto — Mon, 20 Jan 2025 00:00:00 +0800

The 150/275 kV Southern Sumatra Interconnected System (in Bahasa: Sumbagsel) is crucial for providing reliable and sustainable electricity to the region. As network complexity and energy demand grow, challenges related to dynamic security intensify. This study assesses the system's ability to maintain stability during disturbances. Analyses using DIgSILENT PowerFactory software evaluated system responses to fault scenarios, particularly large generator losses, focusing on rotor angle, system frequency, and bus voltage after disturbances. Results show that the Sumbagsel interconnection has critical points prone to dynamic instability. While the system can remain stable within safe limits if disturbances don't exceed handling capacity, mitigation measures like improved coordination between generation and transmission networks are necessary. This study aims to enhance the power system's reliability in the region and prepare it for future operational challenges.

DEVELOPMENT OF DIGITAL TRANSFORMATION SUPPLY CHAIN MANAGEMENT MATURITY MODEL AT PT PLN NUSANTARA POWER

Gumilang Cahya Prayoga, Made Andriani — Mon, 20 Jan 2025 00:00:00 +0800

PT PLN Nusantara Power, a subsidiary of PT PLN, has embarked on a digital transformation journey and implemented an effective organizational structure to support strategic initiatives in 2024. The digital transformation in the Supply Chain Management (SCM) sector began in 2021 with the introduction of E-Procurement. Maturity measurement of E-Procurement usage started in 2022 to encourage its adoption. Although technology has been integrated into SCM processes through supporting applications and Enterprise Resources Planning (ERP), a comprehensive maturity assessment of digital SCM application has not been conducted. In mid-2024, an enabler strategy for organizational effectiveness was applied to SCM processes in power generation units, impacting the uniformity of SCM maturity assessment loads. This research develops a SCM maturity model that includes digital SCM transformation assessment instruments and remaps the maturity model to ensure balanced and collaborative assessment loads. The model features four dimensions consisting of three SCM dimensions and a single dimension specifically for digital transformation, with nine indicators across five maturity levels: Fire Fighting, Stabilizing, Preventing, Optimizing, and Excellence.

Development of a Rooftop PV Acceptance Model Among the Public in Indonesia and Employees of PT PLN (Persero)

Tubagus Riady, Ari Widyanti, Aji Lesmana, Alamsyah Anwar — Mon, 20 Jan 2025 00:00:00 +0800

The adoption of photovoltaic (PV) technology is vital for sustainable energy solutions, particularly in Indonesia's electricity sector. This study investigates the acceptance of rooftop PV systems among the general public and employees of PT PLN (Persero) using the Theory of Planned Behavior (TPB) framework. Data from 366 respondents (179 public, 187 employees) were analyzed through Partial Least Squares Structural Equation Modeling (PLS-SEM). Key findings reveal that the public’s adoption intention is significantly influenced by Subjective Norm (β = 0.212, p < 0.05) and Attitude (β = 0.463, p < 0.001), with economic incentives (β = 0.279, p < 0.001) and perceived benefits (β = 0.266, p < 0.001) playing a major role. Conversely, employees’ adoption intention is predominantly driven by Attitude (β = 0.689, p < 0.001), influenced by environmental benefits (β = 0.311, p < 0.001) and perceived incentives (β = 0.323, p < 0.001). The structural model explains 57.3% and 69.5% of the variance in adoption intention for public and employee groups, respectively. This study contributes to understanding adoption drivers and provides actionable recommendations for PT PLN, including targeted communication strategies, infrastructure enhancements, and cultural alignment initiatives to promote rooftop PV adoption.

Technical Feasibility Analysis of the 500 kV Extra High Voltage Overhead Transmission System Project in Sumatra

Tue, 21 Jan 2025 00:00:00 +0800

The 500 kV Extra High Voltage Transmission Line project in Sumatra is a critical infrastructure initiative designedto improve the efficiency and reliability of power transmission across the island. This study evaluates the technical feasibility of the project by analyzing key aspects such as operational efficiency, structural integrity, and environmental impact. The project aims to address growing energy demands in Sumatra while resolving bottlenecks in the existing 275 kV transmission system. It also facilitates the integration of renewable energy sources, such as geothermal and hydroelectric power, into the grid, contributing to a reduced reliance on fossil fuels and supporting Indonesia’s transition toward sustainable energy. The findings suggest that the project will significantly enhance the stability of the Sumatra power grid, optimize energy distribution, and promote environmental sustainability. Overall, the project is deemed feasible and essential for securing the region’s long-term energy needs.

Interplay Between Tradable Green Certificates and Carbon Emissions Trading: A Literature Review

Andita Nastasia Lazuardi, Hasrini Sari — Mon, 20 Jan 2025 00:00:00 +0800

This study focuses on the intertwined challenges of climate change and sustainability, emphasizing the role of green energy certificates (TGCs) and carbon emissions trading (CET) as crucial instruments for mitigating greenhouse gas emissions. Countries that signed the Paris Agreement are employing these mechanisms to achieve their Net Zero Emissions (NZE) goals. Green certificates promote renewable energy investment, while carbon trading sets emission limits. However, the interaction between these systems is complex and requires careful coordination to avoid misalignment and conflicting incentives. The literature review methodology used in this study highlights how different nations implement TGCs and CET, assessing their interaction in various markets. In China, TGC-CET coupling supports renewable energy growth but faces policy redundancies, whereas in Sweden-Norway, TGC and EU ETS collaboration has proven effective, though further integration with carbon policies is needed. The Netherlands illustrates the risks of poor policy alignment between TGCs and CET, potentially undermining climate goals. The findings stress the importance of harmonizing these systems, ensuring that they function synergistically to optimize emission reductions and drive global climate policy objectives.

Prediction of Electrical Load at PT PLN (Persero) Jayapura Using Recurrent Neural Network and Long Short-Term Memory Models

Dwi Putra Prasatya, Finny Oktariani — Mon, 20 Jan 2025 00:00:00 +0800

The primary challenge in Power System Operation Planning is the uncertainty in predicting electricity load. Inaccurate electricity demand forecasts can lead to issues such as resource wastage, increased operational costs, and supply failure risks. Traditionally, operational planning has relied on estimating load history using Microsoft Excel worksheets, with calculations based on load
growth (%) from previous periods. This research aims to improve the accuracy of electricity load prediction for system operation planning at PT. PLN (Persero) Jayapura by utilizing deep learning models, specifically Recurrent Neural Network (RNN) and Long Short-Term Memory (LSTM). For model optimization, a grid search method was employed for hyperparameter tuning, ensuring the best performance in load forecasting. The study was conducted at PT. PLN (Persero) Jayapura, using daily electricity load data from January 2020 to August 2024, sourced from the SCADA (Supervisory Control and Data Acquisition) histori server. The results showed that the LSTM model outperformed the traditional RNN. While the RNN model achieved a Mean Absolute Error (MAE) of 1.106, a
Root Mean Squared Error (RMSE) of 1.7650, and a Mean Absolute Percentage Error (MAPE) of 0.0142, the LSTM model demonstrated more accurate predictions with a MAE of 1.0047, RMSE of 1.6186, and MAPE of 0.0129. These findings demonstrate the potential of LSTM, enhanced by grid search optimization, for improving load forecasting accuracy and contributing to more reliable power system operation planning.

Health Index Modelling in Condition Assessment of Gas Insulated Switchgear

Yushof Zaky Abdillah, Bryan Denov, Umar Khayam — Mon, 20 Jan 2025 00:00:00 +0800

Gas Insulated Switchgear (GIS) is essential in electrical distribution networks, especially in space-constrained areas, offering efficiency and reliability. However, GIS is prone to degradation from environmental conditions, mechanical stress, and improper operations, requiring periodic assessments to maintain reliability. Traditional Health Index (HI) methods evaluate GIS primarily based on physical conditions, neglecting factors like asset age, operation frequency, and environmental impacts that influence performance. This study enhances GIS condition assessment by integrating the Conditional Factor (CF) value into the HI model, providing a broader risk evaluation, particularly for tropical environments. A unique contribution is the inclusion of Frequent Lightning Incidence in the CF calculation, alongside maintenance history, pollution levels, subsystem conditions, and surge arrester readiness. These factors improve the comprehensiveness of the Overall Health Index (OHI), combining HI and CF. The OHI model aims to improve accuracy in evaluating GIS conditions, enabling better maintenance planning and reducing failure risks in tropical regions like Indonesia. This advanced model supports informed decision-making and extends the lifespan of GIS assets by addressing both visible and latent risk factors, ensuring network reliability in challenging environments.

An Evaluation of Ulumbu Geothermal Development Drilling Trough Expected Monetary Value Analysis

Mon, 20 Jan 2025 00:00:00 +0800

PT PLN (Persero) plans to drill 10 wells for the development of Ulumbu Geothermal Power Plant (Unit 5, 20 MW), consisting of 5 production wells, 2 contingency wells, and 3 reinjection wells. This campaign includes semi-exploratory drilling in the Lungar area, believed to be the main upflow zone, and proven reservoir drilling in the Wewo area. The decision between starting in Lungar or Wewo requires quantitative analysis using Expected Monetary Value (EMV), factoring in Probability of Success (POS). The EMV analysis showed that drilling from the Wewo area, with a higher POS due to proximity to the proven reservoir, is the optimum alternative. Drilling in Lungar will follow to delineate and confirm a larger geothermal prospect, potentially supporting the development of PLTP Unit 6 (20 MW). By balancing the drilling risks and rewards, the strategy aims to maximize the success of the campaign and ensure the completion of Unit 5 planned capacity.

Techno-Economic Evaluation of Suralaya CFPP Unit 1 Coal Gasification for Gas Supply Cilegon CCPP

Syahrial Nurul Huda, Wibawa Hendra Saputera, Nurulhuda Halim — Mon, 20 Jan 2025 00:00:00 +0800

The Indonesian government’s energy transition policy includes phasing out Coal-Fired Power Plants (CFPPs), such as Suralaya CFPP Unit 1, and addressing natural gas limitations in Combined Cycle Power Plants (CCPPs) like Cilegon CCPP. This study introduces a novel approach as the first to integrate syngas production using Mitsubishi Heavy Industries (MHI) entrained-flow gasifier fueled by coal from a retiring CFPP to support CCPP operations. The innovation lies in repurposing decommissioned CFPP assets, reducing dependence on natural gas while leveraging advanced gasification technology to maintain power generation efficiency. The MHI gasifier achieves 99,9% carbon conversion with CGE 77,2 % and produces syngas with an LHV of 4,575 MJ/kg, enabling a combined cycle output of 306 MW with 50,36% efficiency. This process also reduces air consumption by 25%, from 2.188.000 kg/h to 1.650.000 kg/h, contributing to environmental sustainability. Economic analysis estimates construction costs at Rp41,3 trillion for the gasification plant and Rp1,02 trillion for a 15 km gas pipeline from Suralaya to Cilegon. This study pioneers a pathway for integrating gasification technology into Indonesia’s energy infrastructure, demonstrating a practical and sustainable strategy to transition from coal dependence to cleaner energy systems while maximizing efficiency and minimizing environmental impact.

Corrosion Detection at Transmission Accessories Using Combination of Object Detection, Image Classification and Background Removal

Edy Sucipto, Nugraha Priya Utama — Mon, 20 Jan 2025 00:00:00 +0800

Inspection of electrical transmission accessories is an important aspect of maintaining the reliability of electricity supply. But due to the large number of components that need to be inspected and cost to maintain it, lately there has been a trend to inspecting it by autonomous using AI or Deep Learning. And one of state of the art in object detection model is YOLO and its variant from Ultralystic. Using it in object detection and image classification task using new dataset and exclusive form Indonesia environment that researcher never has been done, that is Clevis, Dead end, Shackle, Tension clamp, Hole and Bolt. Datasets are also provided in several types to target the highest score. Also use another model like YOLOX and RT-DETR for object detection, and VGG-19, DenseNet-201, etc. to image classification. And the result is that smaller number of class and using larger object can improve metric score result overall, and it get by model YOLOv9e, it can reach 0,972 in mAP@0,5. And the removal of background will lead to poor metric score, even it cannot reach 0,20 poin in mAP@0,5 except using YOLOX-X that reach 0,661. Combination between object detection and image classification seems good at training and testing part, but when it is used with original data the result decreases, from about 0,94~0,97 to 0,82~0,84 precision. This is likely due to IoU limitations when extracting it from object detection which causes lower quality dataset that deliver to image classification process.

Geochemical Study of the WKP Ungaran, Central Java

Tue, 21 Jan 2025 00:00:00 +0800

This study aims to analyze the composition, origin, and characteristics of thermal fluids in the Ungaran geothermal field, Central Java, and to estimate the reservoir temperature using geothermometers. The methods used include geochemical surveys, chemical analysis of water and gas, and interpretation of geoindicators. The results show that the thermal fluids in this field have chloride, bicarbonate, and sulfate water types, with the upflow zone dominated by sulfate water and the outflow zone by bicarbonate water. Stable isotope analysis indicates water-rock interaction in the subsurface. Reservoir temperature estimates based on silica geothermometers range from 110-179°C, while gas geothermometers indicate temperatures between 220-270°C. The conceptual model produced depicts a geothermal system controlled by geological structures such as normal faults and calderas. This study provides significant insights into the Ungaran geothermal system and can serve as a basis for further exploration.

Heat Rate and Efficiency Evaluation of Cofiring Biomass in CFB Boiler Coal-Fired Power Plant

Reza Ibnu Prasojo, Ari Darmawan Pasek — Mon, 20 Jan 2025 00:00:00 +0800

Cofiring activity is an effort to carry out fuel switching in stages at the existing coal power generation. This is done to accelerate the implementation of renewable energy in 2025 by 23% according to the government's target. However, implementing biomass cofiring in coal power generation also has challenges, such as selecting the appropriate type of biomass, modifying the combustion system, and handling potential side effects such as the formation of slagging, fouling and agglomeration. This paper reviews the effect of cofiring on the CFB boiler performance and the effect on flue gases emissions. It is hoped that the results of this paper will provide a better understanding of the potential for utilizing biomass in electricity generation, as well as recommendations for larger scale implementation in the future. In addition, the effects of incorporating biomass, considering factors such as the type, proportion, particle size, and method of injection, as well as the burner's design and operational mode, on flame characteristics and emissions have been extensively studied. The findings indicated that the integrated system could offer a favorable approach to electricity generation. To enhance the overall efficiency of the process and minimize exergy destruction, an enhanced process integration technique was implemented.

A Multicriteria Decision Making for Low Emission Technologies in Coal-Fired Power Plant

Vita Rahmayani, Joko Siswanto — Wed, 12 Feb 2025 00:00:00 +0800

Nitrogen oxides (NO_x), sulfur oxides (SO₂) and particulate matters (PM) are the major pollutants emitted from burning coal in power stations. Clean coal technologies are technologies designed to enhance the environmental performance of coal through use of the technology to an acceptable level. To mitigating this problem, selecting low emission technologies in coal fired power plant is needed. Various criteria and subcriteria is considered through the selection for low emission technologies such as economic, environmental, technical and technology. This paper focus on identfying multicriteria for low emission in pollution control specified in FGD and SCR technologies. Considering LCOE and lifetime of power plant as criteria or subcriteria in selecting technologies in coal fired plant. This research methodology used is literature review and designed to emphasizing more specific criteria and subcriteria relevant to FGD and SCR technologies in coal power plants. Relevant studies have been used as reference to ensure the multicriteria comprehensively represent for selecting low emission technologies.