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The physical work environment in the Aerosol Production Department of PT XYZ experienced problems related to excessive room temperatures reaching 37.3°C and chemical odor pollution caused by vapor recirculation from the coating oven process. These conditions potentially reduced operator comfort and concentration. This study aimed to analyze the effectiveness of the Kaizen approach through the Plan-Do-Check-Act (PDCA) cycle in controlling production room temperature and improving air quality. A quantitative descriptive method with an Action Research approach was employed. Problem identification and root cause analysis were conducted using the 7 QC Tools, particularly the Pareto Diagram and Fishbone Diagram. Improvement actions included the installation of turbine ventilators, aluminum foil roof insulation, and a 3-meter vertical exhaust ducting system. The results showed that the average room temperature decreased from 34.6°C to 27.4°C, representing a reduction of 7.2°C, while the peak daytime temperature decreased by 8.7°C and met the established threshold limit value. In addition, chemical odor pollution was completely eliminated. Therefore, the Kaizen-PDCA approach proved effective in improving the physical work environment sustainably.

The increasing demand for electrical energy and the limited availability of fossil fuels have driven the development of renewable energy sources, including marine current energy, which remains underutilized in coastal and remote maritime regions. This study presents the design and realization of a small-scale marine current power generation prototype using a horizontal axis propeller turbine with a NACA S814 blade profile and analyzes the effect of turbine rotational speed on electrical power output. The system converts marine current kinetic energy into mechanical energy through turbine rotation and subsequently into DC electrical energy using a generator, which is stabilized by a Buck–Boost Converter and Maximum Power Point Tracking (MPPT) for charging a 12 VDC battery. Real-time monitoring of electrical and mechanical parameters is implemented using an Internet of Things (IoT)–based system comprising an ESP32 microcontroller, a PZEM-017 sensor, and an RPM sensor. Experimental results demonstrate a positive correlation between water flow rate, turbine rotational speed, and generator output voltage. The system begins operating at a minimum flow rate of 35.2 L/s at 56 RPM, producing 0.2 V, while optimal performance is achieved at 45.3 L/s and 516 RPM, generating up to 13.3 V. These results indicate that the proposed prototype is a viable alternative renewable energy source for marine applications.

The low thermal efficiency of Gas Power Plants (PLTG) due to exhaust gas heat loss drives the implementation of cogeneration at PLTGU Block II PT. PLN Indonesia Power UBP Semarang. This study analyzes the performance of the Gas Turbine Generator (GTG), combined cycle efficiency, and Exergy distribution using a 3-3-1 configuration. The research utilizes actual operational data from January 28, 2026, sampled at 10-minute intervals. Results indicate that cogeneration via a Heat Recovery Steam Generator (HRSG) significantly enhances plant efficiency. The GTG output ranged from 273–283 MW with an efficiency of 30.0–30.2%. Following combined cycle integration, system efficiency increased to 43.9–44.4%, a gain of approximately 14%, with a heat rate of 11,916–11,988 kJ/kWh. Exhaust heat of 665–713 MW was recovered to generate an additional 130 MW through the Steam Turbine Generator (STG). Exergy analysis reveals that the largest irreversibility occurs in the GTG combustion process (285 MW), followed by the HRSG (185 MW) and STG (49 MW).

The foundation of turbine machines in industrial buildings must be able to withstand static and dynamic loads caused by operational vibrations. Generally, reinforced concrete block foundations are used due to their good stability. However, under certain conditions such as limited land, decreased soil bearing capacity, and the need for structural rehabilitation, their application becomes less effective. Therefore, this study aims to analyze the use of Micropile foundations as an alternative for turbine machine foundations at Candi Baru Sugar Factory, Sidoarjo.The research method includes literature studies, soil data collection through Cone Penetration Test (CPT), machine technical data analysis, and the design and analysis of Micropile foundations. The analysis covers bearing capacity, settlement, dynamic response, pile cap design, and cost estimation.The results indicate that Micropiles with a diameter of 0.20 m, a length of 2 m, five piles, and a pile cap size of 2 m × 2 m × 4.5 m are able to safely and stably support the machine load. In addition, this system is considered more efficient in terms of construction time and implementation. Therefore, Micropile foundations are recommended as an effective and economical alternative for turbine machine foundations.

Gas turbine generators play an important role in providing electrical energy, especially in the maritime sector, but they are vulnerable to disturbances such as overcurrent and undervoltage, which can cause equipment damage. This study aims to design and test an automatic protection system based on the ESP32 microcontroller with the INA219 sensor to detect current and voltage, as well as a relay as a circuit breaker. The method used is an experimental approach including static and dynamic testing, both with and without a 5W AC lamp load as a simulation of real loading conditions. Test results show that the average sensor reading error is 2.65% for current and 1.76% for voltage, which is still within the ±3% tolerance limit. The system is able to disconnect the load when any parameter exceeds the protection threshold, although there are slight inconsistencies in the relay response due to sensor reading fluctuations. In conclusion, this automatic protection system is proven to be 85% accurate and responsive in maintaining the operational reliability of the gas turbine generator, making it applicable as a preventive solution against electrical disturbances in marine environments.

The energy that is stored in water can be used to generate electricity by taking advantage of the potential energy available, like the energy from waterfalls and the movement of flowing water. Micro-hydropower plants (PLTMH) are one solution to address the energy crisis, particularly in electricity. VDI 2221 is a method that German engineers use as a guideline when designing construction projects. The VDI (Verein Deutsher Ingeneure or German Engineers Association) design process involves several stages: task description, design concept determination, physical design, and detailed design. Based on the solution principle matrix table, 3 variants were obtained, each of which has criteria. Of the 3 variants that have been evaluated, variant 2 was obtained with results that met the requirements. The cost analysis table shows that the total cost for designing a prototype test equipment for a micro-hydroelectric power plant (PLTMH) based on a laboratory-scale crossflow turbine is Rp 10,032,000. This cost includes instrumentation, control and electrical panels, measuring instruments, pipe instruments, frame and casing, and unforeseen costs.

Accurate wind turbine power curve modeling plays a crucial role in performance evaluation, energy yield estimation, and data-driven control strategies. However, actual power curves often exhibit non-linear behavior influenced by atmospheric variability, measurement noise, and SCADA anomalies, making conventional modeling approaches less effective. This study proposes an optimized logistic power curve model whose parameters are tuned using Particle Swarm Optimization (PSO) to improve predictive accuracy. The analysis uses the Wind Turbine SCADA Dataset from Kaggle, which undergoes extensive preprocessing including physical rule filtering, outlier detection with the Interquartile Range (IQR) method, anomaly removal, and smoothing of the power signal. A three-parameter logistic model is selected due to its ability to capture the typical S-shaped relationship between wind speed and power output. PSO is applied to identify optimal model parameters by minimizing the Mean Squared Error (MSE), utilizing 40 particles over 200 iterations. The optimized model achieves strong predictive performance with RMSE of 404.09, MAE of 179.96, and R² of 0.904 on the test set, indicating that more than 90% of the variability in actual power can be explained by wind speed. Residual analysis reveals heteroscedastic patterns and slight overestimation in mid-range wind speeds, yet overall model consistency remains high. Comparative evaluation against Linear Regression, Random Forest, and logistic modeling using curve_fit shows that the Logistic–PSO approach provides the most accurate and stable predictions. These findings demonstrate that combining logistic modeling with PSO offers an effective and robust method for data-driven wind turbine power curve optimization.

The Gas and Steam Power Plant (PLTGU) utilizes exhaust heat from gas turbines to produce steam, which is then used to drive steam turbines. One of the critical processes in this system is seawater desalination, which requires reliable measuring instruments to ensure the continuity and quality of the water supply. The Differential Pressure Flow Transmitter type Azbil JTD920S is used to measure fluid flow rates at four main points: Sea Water Flow (feed), Distillate Water Flow, Condensate Water Flow, and Sea Water to Ejector Condenser Flow. A decline in transmitter performance may occur due to environmental factors, corrosion, and high workload, making periodic preventive maintenance (PM) essential. This study aims to analyze the transmitter’s performance by comparing PM data with the manufacturer’s maximum specifications using literature studies, direct observation, and interviews. The calculation results show that the highest performance levels are found in the Distillate Water Flow (73.53%) and Sea Water to Ejector Condenser Flow (73.87%) lines, while the lowest is in the Condensate Water Flow (49.00%). These findings emphasize the importance of close monitoring of high-performance transmitters to prevent premature failure and maintain the efficiency of the desalination process.

This research aims to design and build an Internet of Things (IoT)-based electrical energy monitoring system on a Darrieus turbine prototype to optimize energy yield. This research using the Research and Development or RnD method, this method was chosen by researchers because it can provide solutions, enable the development and application of more effective learning methods. The system uses NodeMCU ESP32 sensors to measure important parameters such as voltage, current, power, and energy produced by the turbine. The collected data is then analyzed and visualized through IoT platforms such as ThingsBoard, which allows real- time monitoring of the turbine's performance. The integration of IoT in this system is expected to improve energy use efficiency by providing useful information for management and decision-making in turbine operations. This research also fills the gap in Darrieus turbine development with an approach that combines IoT-based monitoring and energy yield optimization, and can be applied to improve the efficiency of renewable energy in Indonesia

Renewable energy is non-fossil energy that can be renewed and managed sustainably, such as solar, wind, water, and biomass. To overcome dependence on weather conditions, this energy can be combined with alternative energy sources such as piezoelectric sensors, which can convert pressure into electrical energy. This study aims to design a prototype monitoring system for hybrid electric energy using solar panels, wind turbines, and piezoelectric elements as alternative energy sources on board ships. The use of Internet of Things (IoT) technology is key to monitoring and managing these energy sources in real-time and automatically through integrated sensors and software. This research uses the Research and Development (R&D) method by creating a prototype that combines solar panels, wind turbines, and piezoelectric components as energy sources and designing a monitoring system based on the Internet of Things (IoT) using the Kodular application. Several system components were tested through two types of testing: static and dynamic testing. The test results showed that the solar panel had the most stable performance with a voltage of approximately 16.50V and a current of 2.41A occurring between 13:00 and 16:00 WIB. The wind turbine was able to operate at low wind speeds and reached its highest voltage of 3.63V and current of 1.14A on the fifth day at 20:00 WIB with a wind speed of 1.1 knots. The piezoelectric system generated power according to the pressure and frequency of footstep impacts. The highest voltage recorded for a 70kg subject was 4.11V with a current of 0.19A. This hybrid system has the potential to be an environmentally friendly energy support solution on board ships.

This research aims to develop and evaluate the performance of a steam plant prototype designed as an alternative source of electrical energy to support the Vessel to Grid (V2G) concept. Utilization of backup energy on ships is becoming important as electricity demand increases and demands for a more sustainable electrical system. This system relies on ESP32 microcontroller technology as a control center that functions to monitor and control several key parameters, including steam pressure, combustion temperature, boiler water level, and the generated electrical voltage. The research method used is an experiment with a static and dynamic testing approach. Static testing is carried out to measure the performance of main components such as the boiler, turbine, and generator separately, while dynamic testing focuses on evaluating the overall system by involving the integration of sensors and supporting actuators. The test data is then analyzed quantitatively to determine the system's response to variations in steam pressure, temperature, and other operational conditions. The results show that the steam produced by the boiler is able to rotate the turbine, thereby driving the generator to produce electricity. The maximum voltage achieved is 25.7 volts at a steam pressure of 50 psi. The highest energy conversion efficiency was recorded at 4%, while the lowest efficiency was 0.9%. These findings demonstrate that, despite its relatively low efficiency, the prototype can function as an alternative energy source and emergency backup solution. Thus, this research provides an initial contribution to supporting the implementation of the V2G concept through the development of a small-scale steam plant-based energy conversion system.

As an archipelagic country, Indonesia has significant potential for the utilization of renewable energy, particularly wind energy in maritime areas with low wind speeds (3–6 m/s). This study aims to design and test a vertical Savonius wind turbine system equipped with a Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) algorithm as a power source for shipboard water heating systems. The research method applied is Research and Development (R&D), integrating several components such as a DC generator, full-wave bridge rectifier, INA219 current sensor, anemometer cup sensor, ESP32 microcontroller, and a monitoring interface utilizing Google Spreadsheet and a 20x4 LCD. The system was tested under two operating conditions: without MPPT and with MPPT. The experimental results show that the application of the MPPT algorithm successfully increased power output by up to 272.64% while maintaining voltage stability despite varying wind speeds. Nevertheless, the average output power of 2.605 W remained insufficient to meet water heating requirements within a short time. For example, charging a 12V 50Ah battery would require approximately 9.6 consecutive days of operation, highlighting the system’s limitations in high-demand scenarios. Despite these constraints, the findings demonstrate that the vertical Savonius wind turbine integrated with MPPT has strong potential as a clean and environmentally friendly alternative energy solution for maritime applications, particularly for small-scale onboard electrical loads. This study contributes to renewable energy utilization in the shipping sector and provides a foundation for further technological development and optimization.

This research explores the engineering and performance evaluation of 17-4 PH stainless steel as a potential material for turbine blades in geothermal power plants (PLTP). To promote renewable energy innovation in industrial engineering, this study focuses on improving material reliability through microstructural optimization and mechanical property control. The material was produced using the investment casting method at PT SPVMB and then subjected to four heat treatment variations: H900, H1025, AVG (average), and as-cast conditions, with reference to ASTM A747 standards. Mechanical and corrosion characterization were performed through hardness and tensile tests, electrochemical corrosion analysis using geothermal water from the Dieng PLTP, and microstructural observation using an optical microscope. The results showed that the H900 condition had the highest hardness and yield strength (48.46 HRC and 939.25 MPa), but its corrosion rate was relatively high. In contrast, the H1025 heat treatment provides balanced mechanical strength (43.88 HRC and 860.91 MPa) with the lowest corrosion rate (0.027 mm/year), supported by a uniform tempered martensite structure. These findings indicate that heat treatment optimization significantly improves the suitability of 17-4 PH stainless steel for sustainable geothermal applications. The H1025 condition meets all the requirements for geothermal turbine blades, including hardness, strength, and corrosion resistance, potentially extending component life and reducing maintenance costs. Furthermore, the results of this study strengthen the agenda for developing durable, environmentally friendly materials to support renewable energy systems. This study also provides practical insights for industry in selecting the optimal heat treatment that combines mechanical performance and corrosion resistance in extreme geothermal environments.

The increasing need for electrical energy in Indonesia encourages the development of new renewable energy (EBT), including hydroelectric power plants (PLTA) as an environmentally friendly solution. This research was conducted at the Mentawa Dam, West Toili District, Banggai Regency, Central Sulawesi, to analyze the potential of water energy that can be utilized as a source of micro-hydro power plants (PLTMH). This dam currently functions as irrigation and a tourist attraction, but has significant potential to generate sustainable electrical energy. The research methods include measuring water discharge using the float method, measuring the height of the water fall (head) with an altimeter and GPS, and analyzing the potential for electrical power using the formula P = η ⋅ ρ ⋅ g ⋅ Q ⋅ H. The measurement results show an average water discharge of 3.01 m³ / s and a water fall (head) of 6.56 meters. With a turbine efficiency of 80%, the potential electrical power that can be generated reaches 154.76 kW. This study recommends the use of Kaplan turbines in Mentawa Dam, which are ideal for large discharge conditions and low to medium heads, and can adapt to discharge fluctuations, making it an optimal choice to maximize energy potential. This research is expected to provide sustainable energy solutions for the people of Toili Barat District and support the development of the tourism sector.

This study aims to analyze the performance and conduct reverse engineering of the Francis Turbine runner at the Tanggari 1 Hydroelectric Power Plant (PLTA Tanggari 1) through 3D scanning and Computational Fluid Dynamics (CFD) simulation. The main objective is to evaluate the turbine's efficiency and identify areas for improvement in the runner geometry. Data from the 3D scan are used to reconstruct a CAD model, which is then numerically tested to predict hydraulic performance. CFD simulations are carried out under various guide vane openings and head variations. The simulation results show a maximum efficiency of 93% at a head of 122.4 meters with a guide vane opening angle of 26° and a flow rate of 8.5 m³/s. The resulting performance curve and hill chart indicate the optimal operating point or Best Efficiency Point (BEP), which serves as a critical reference for turbine operation settings. Flow phenomena such as separation and vortex formation were detected under off-BEP operating conditions, potentially causing pressure fluctuations and vibrations. As a technical recommendation, it is advised to operate the turbine close to the BEP to minimize vibrations and energy losses. Furthermore, the runner geometry obtained from reverse engineering can serve as a basis for component refabrication and the development of new runner designs that are more adaptive to varying load conditions.

Electrical energy is a vital need to support daily life in various sectors such as industry, housing and government. In Indonesia, the majority of electrical energy is still produced from fossil fuel plants, which have significant environmental impacts and limited resources. Therefore, the development of renewable energy is crucial to reduce dependence on fossil fuels. One promising alternative is the Micro Hydro Power Plant (PLTMH), which uses flowing water to produce electrical energy. This research focuses on the implementation of MHP in Babakan Banten Village, Bogor Regency, an area with the potential for abundant water flow throughout the year. This project aims to provide a reliable electricity supply for communities, most of whom do not yet have access to electricity from the national grid. This study includes the process of planning, assembling and testing the MHP system using field data such as river water discharge, land elevation (head) and other technical specifications. The measurement results show that the PLTMH with a generator capacity of 2 kW is able to meet the electricity needs of 18 houses in Babakan Village, Banten. System testing shows good operational stability with optimal turbine rotation at full load and results in accordance with planning. It is hoped that the implementation of this PLTMH will not only increase accessibility to sustainable electrical energy, but will also have a positive impact on the welfare of local communities. Utilization of locally available natural resources not only reduces dependence on conventional energy, but also becomes a real example of the application of technology for sustainable development in remote areas of Indonesia.

Hydroelectric Power Plants (HPP) are a type of power plant that utilizes renewable energy from water flow. The hydroelectric system works by converting the kinetic energy of flowing water into mechanical energy, which is then converted into electrical energy. Water flows through a penstock directed towards the turbine, where it strikes the turbine blades, causing rotation. To maintain the stability of the turbine's rotational speed at the Maninjau HPP, a governor system is used. The Maninjau HPP consists of four generating subunits with a nominal rotational speed of 600 rpm. The governor system functions to stabilize the turbine's rotation at the nominal speed of 600 rpm, as the speed affects the generator's output frequency. The stabilization process is carried out by adjusting the Guide Vane openings, which are the blades surrounding the turbine. The Maninjau HPP has a speed drop of 3%, with a frequency reduction of 1.5 Hz. Additionally, a frequency change of 0.1 Hz will result in a load change of 0.13 MW.

The largest source of energy currently utilized is still predominantly from fossils. Fossil energy sources are non-renewable so over time they will run out. So it is necessary to utilize renewable energy sources. One renewable energy source that is environmentally friendly and easy to obtain is wind energy. Wind is a collection of air that is experiencing movement due to a difference in pressure on the earth's surface. Wind will move from areas of high pressure to areas of lower pressure. Experimental research on wind energy is a useful energy that can be put to good use. Wind energy is a form of energy that comes from utilizing air flow in the atmosphere to produce mechanical or electrical energy. The main technology used to utilize wind energy is a wind turbine, which converts wind kinetic energy into electrical energy through a generator. Which of course also requires sufficient wind speed so that the wind turbine can rotate and produce mechanical movement in the form of rotational torque which can then be converted into electrical energy. Wind energy has great potential as a clean, sustainable and environmentally friendly resource, as it does not produce greenhouse gas emissions or hazardous waste during its operation. However, wind energy development faces challenges such as fluctuations in wind speed, large land requirements, visual impacts, and potential disruption to local ecosystems. With technological innovation and careful planning, wind energy can be a significant solution to meet global energy needs in a sustainable manner.

The Sutami Hydroelectric Power Plant managed by PLN Nusantara Power UP Brantas is one of the power plants that relies on air resources to generate electricity. However, the optimization of electricity production can still be improved by considering the availability of primary energy and the interests of related stakeholders. This study aims to create a simulation of operating patterns to optimize the daily electricity production of the Sutami Hydroelectric Power Plant using the MS Excel Solver program. The total electrical energy in March based on the results of the simulation calculation was 56,537,445.55 MWh, 3.09% greater than the actual data of 54,792,800 MWh. The results of the simulation calculation of electricity production in June 2024 were 27,564,315.75 MWh, 3.82% greater than the actual data of 26,511,800 MWh. In FDC 2014-2023, the average mainstay discharge is 32 m3/s available throughout the year to be utilized by water turbines to produce a minimum power of 20 MW. Meanwhile, from the estimated historical data obtained by FDC 2024-2033 with an average mainstay discharge of 40.68 m3/s to produce a minimum power of 30 MW.

Wind Turbine Blades are one of the renewable energy sources that are the main solution to reduce excessive use of conventional fuels. Wind Turbine Blades absorb kinetic energy into mechanical energy which is then converted into electrical energy by the generator. This study uses the National Advisory Committee for Aeronautics (NACA) 1.2 horizontal axis wind turbine blade design with a taper type (having a wide base and a small tip). The initial wind turbine blade data was obtained rotating at a wind speed of 3.5 m/s with a voltage of 5.1 Volts. This blade design was carried out using maximum wind speed data of 9.5 m/s and minimum wind speed data of 3.6 m/s, then current and voltage data were obtained. The results of this study confirm that the design of this wind turbine blade affects the efficiency of converting wind energy into electricity. This taper type wind turbine blade is designed to produce optimal performance in a certain wind speed range.