ASEAN Journal of Systems Engineering
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SENSITIVITY ANALYSIS OF HYPERPARAMETER IN SOLAR ENERGY PREDICTION MODEL USING GRADIENT BOOSTING METHOD
Full text linkSolar energy prediction is one alternative to handling unpredicted conditions of weather and solar radiation intensity. It could be the most important factor in achieving stability in electricity generation using solar energy resources. In making predictions, the use of machine learning models has been carried out by various methods, and in this study, the method used for the algorithm model is gradient boosting. In the modeling process using gradient boosting, several hyperparameter settings are needed. Hyperparameters have an important role in producing stable predictive patterns and can avoid overfitting or underfitting conditions. In this study, the accuracy and speed of prediction of the machine learning model with the gradient boosting approach, namely XGBoost and LightGBM, were analyzed in relation to setting the hyperparameter learning rate and max depth of the model's prediction pattern. The dataset used spans 6 months at a data resolution rate of every 5 minutes and includes meteorological data at the location point of Energy Laboratory UKRIM Yogyakarta as well as the output value of PLTS power and temperature panels onsite. Setting the hyperparameter learning rate in the highest and lowest conditions generates accuracy values with a difference of 2% and about the same prediction speed. With nMAE values of 2.84% and 1.35% and nRMSE values of 6.11% and 3.68%, respectively, the higher learning rate results in lower error values for both models. The XGBoost model shown tendency for overfitting and slower prediction speeds with the highest max depth setting. The prediction speed is faster at the lowest max depth condition, but the XGBoost and LightGBM models both exhibit underfitting
The Role of Renewable Energy in ReducingCarbon Emissions in Cirebon District
Full text linkThe adverse effects of the use of fossil energy such as global warming make people slowly decrease the use of fossil energy including in the electric power generation sector. Emissions from burning fossil fuels such as carbon dioxide are one of the components that make up and dominate the composition of greenhouse gases. It is this greenhouse gas that prevents the sun's heat from being reflected back into the atmosphere, so that it accumulates over many years which causes the temperature of the earth's surface to increase. Slowly the use of fossil energy is stopped and replaced with new renewable energy which produces less greenhouse gases. In meeting the demand for electricity supply, Cirebon Regency is still relying on Steam Coal Power Plants to supply electricity demand. According to projection, Cirebon's total electricity demand will be 109.860,28 GWh by 2050. If Cirebon still continues to use Steam Coal Power Plants until 2050 it's estimated that it will emit 100.489.721,74 tons of carbon dioxide emissions. Cirebon Regency has alternative energy potential from municipal solid waste (MSW) that can be utilized. Every day, every person in Cirebon Regency can produce 0,541 kg of waste. From the observations, the electrical energy that can be generated and utilized from waste until 2050 is 8.360,45 GWh, of which 2.462,34 GWh is generated from organic waste and 5.898,12 GWh is generated from combustible waste. The electrical energy that can be generated from city waste is sufficient for 7,61% of the electricity needs of Cirebon Regency. With an energy mix scheme between PLTU and waste-based power plants, total carbon dioxide emissions can be reduced by 3,05%
TECHNO-ECONOMIC ANALYSIS OF THE POTENTIAL FOR HYBRID POWER PLANT IN GUNUNG SEWU GEOPARK, PACITAN REGENCY
Full text linkGunung Sewu has been designated as a Global Geopark Area by The United Nations Educational, Scientific and Cultural Organization (UNESCO) in 2015. In the preparation of the Gunung Sewu Masterplan as a UNESCO Global Geopark (UGGp), the provision of environmentally friendly and sustainable electricity is one of the strategies to utilize the renewable energy. The application of Hybrid Power Plants (HPP) that utilize wind and solar energy in the industrial and tourism sectors can have a positive impact on regional income where economic growth is one of the strategic issues of Pacitan Regency.The average wind speed in Pacitan is 3.41 m/s and the average solar radiation reaches 5.69 kWh/m2/day so that it can be said that the potential for solar and wind energy in the Gunung Sewu Pacitan Geopark is reliable and feasible to be used as an environmentally friendly energy source. The simulation of HPP that will be implemented at Buyutan Beach illustrates that the system could produce an output of 7,519 kWh/yr. This result is able to meet the annual demand of 4,107 kWh/yr and even exceed the annual requirement.The economic analysis of the simulated HPP system produces a negative Net Present Value (NPV). This could be due to the large value of Operational Expenditure (OpEx) and Capital Expenditure (CapEx) and the low purchase price (National Electricity Company’s feed in tariff). However, this research also proposes a scenario so that the HPP system can still be applied by dividing the cost components contained in the budget plan into two parts. In the proposal obtained cash inflows of Rp. 8,640,834.80/year and a positive or feasible NPV
NATIONAL PLATFORM OF LIFE CYCLE INVENTORY DATABASE IN INDONESIA
Full text linkThe national Life Cycle Inventory (LCI) database needs to be built, collaborated and integrated to harmonize LCI data, research and information systems across all stakeholders nationally. The goals of national LCI data harmonization are to: advance national data, research, and information systems by leveraging multi-agency resources and expertise; improve consistency in Life Cycle Assessment (LCA) methods developed by each institution to develop LCA results for decision-making and public disclosure; and enhance public and national institutions to access harmonized data in a standardized searchable format from a common repository. However, the low number of LCI datasets originating from Indonesia results in using other countries' LCI databases that have the potential for high errors and uncertainties and do not represent supply chain data for specific geographical locations in conducting LCA for Indonesian products. The Research Center for Sustainable Production Systems and Life Cycle Assessment (PR SPB PDH) at the National Research and Innovation Agency (BRIN), an institution tasked with establishing a national database for LCI in Indonesia, is currently entering the stage of collecting LCI datasets. This paper proposes recommendations for developing a national platform for the LCI database in Indonesia. The method used is descriptive qualitative analysis from a comparative review of national databases of various countries. The study reveals that the development that has started fulfilled several criteria. However, some requirements must still be met to become a comprehensive LCI national database
IMPLEMENTATION OF THE IMPORTANCE PERFORMANCE ANALYSIS METHOD IN MEASURING SOLID WASTE MANAGEMENT PERFORMANCE IN SENDAWAR CITY, WEST KUTAI REGENCY
No full textSolid waste management is a public service that must be provided by the government and regulated by law. The Solid waste management service in Sendawar City is currently managed by the local government through the Environmental Government Agency (DLH) of West Kutai Regency. In the service business, an evaluation process is needed in order to know the extent to which the level of performance has been achieved, especially from the point of view of service users. In this study, the method used to evaluate the solid waste management service in Sendawar City is the Importance Performance Analysis (IPA), using five service quality variables, namely reliability, assurance, tangibles, empathy, and responsiveness. Then, five variables are translated into twenty attributes as evaluation material from the service user community.The results of this study found that the level of conformity between the level of performance and the level of importance in the solid waste management system in the City of Sendawar was 78.32% ( good category), definitively meaning that the user community considered the performance of DLH was good, although there were several attributes that, according to the community should be a priority for improvement because they are deemed not optimal, namely the BF2 attribute (availability of garbage bins (TPS) and equipment for transporting garbage), BF4 attribute (safety and health equipment for transport officers) and the DT3 attribute (readiness and responsiveness of the Department in responding to public complaints)
PIAT DEVELOPMENT TOWARDS WELLNESS TOURISM WITH KANSEI ENGINEERING AND KANO MODELS
Full text linkWellness tourism is one of the efforts to revive the Indonesian tourism sector during the transition period of the pandemic to endemic. People seek prevention and health maintenance by traveling to get a better quality of life. Giving rise to wellness tourism as wellness and health tourism in the form of health care based on a healthy natural environment and restoration of relaxation. One of the innovations carried out by PIAT is the development of agro-industry by applying the concept of wellness tourism. Tourist attractions will be more valuable if they can meet the needs of the highest level, namely pleasure. This study aims to: (1) identify the words Kansei of prospective tourists related to wellness tourism. (2) determine the concept model of wellness tourism atmosphere design that suits the pleasure needs of tourists. (3) improve the products and services of the Agrotechnology Innovation Center (PIAT) based on the priority attribute of tourist needs. This research used the Kansei engineering method and the kano model. Semantic Differential (SD) Questionnaire 1 to capture images of wellness attractions. Kansei engineering begins with the collection of tourist pleasure needs in the form of Kansei word, simplifying Kansei word with factor analysis, categorization analysis of Kano models, identification of technical attributes, dissemination of SD 2 questionnaires and questionnaire analysis with quantification theory 1 (QT1) to determine the correlation between tourist attributes and design concepts quantitatively. The results obtained from the first questionnaire, there are nine Kansei words that describe wellness tourism places at PIAT UGM, namely "Worthy-Shady", "Quite Adequate-Good", "Warm-Cool", "Spread-Neat", "Somber-Fun", "Set-Customized", "General-Local Wisdom", "Independent-Existence of Guides", and "Vintage-Latest (Update)". The order of priority of improvement is based on the attraction & one attribute. In addition, this study produced five concepts of wellness tourism service design atmosphere that suit the pleasure needs of tourists, namely: "cool", "local wisdom", "fun", "the presence of a guide", and "good". The results showed that all service design concepts have an R-value of more than 0.8 so all concepts are used in determining service design prototypes
ON-GRID AND OFF-GRID RENEWABLE ENERGY DESIGN AS SWRO (SEAWATER REVERSE OSMOSIS) POWER FOR FRESHWATER NEEDS IN GILI TRAWANGAN (STUDI CASE: GILI TRAWANGAN)
Full text linkIndonesia has 17,504 islands and one of them is Gili Trawangan. Gili Trawangan is one of the favorite tourist destinations in Indonesia which has an area of approximately 6 km2. In order to achieve the development of tourism islands, sufficient water and energy are needed in the area. The island's location in the middle of the sea makes it difficult to get freshwater and energy supplies.In this study, on-grid and off-grid simulations of renewable energy (solar, wind, and biomass) were carried out to determine the potential of integration energy as seawater desalination power as the need for freshwater in the area by calculating NPC (Net Present Cost), COE (Cost of Energy), operational costs, energy, and CO2 emissions. In the off-grid simulation, the lowest NPC and COE integration potentials were found at PV (Photovoltaic) capacities of 102 kW, 14 WT (Wind Turbine), 50 kW BG (Biogas Generator), and 50 kW DG (Diesel Generator) with a value of Rp 17,042,910,000 and Rp 1,587. The lowest operational costs and CO2 emissions are at the PV capacity of 209 kW, 8 WT, 50 kW BG, and 50 kW DG with a value of Rp 292,308,100 and 163 kg/year. In energy production, there is excess production and electrical energy at the PV capacity of 188 kW, 25 WT, 50 kW BG, and 50 kW DG with values of 2,301,533 kWh/year and 1,821,626 kWh/year. On-grid simulation results obtained the lowest NPC and NOE at 30 kW PV, 5 WT, and 50 kW BG with a value 2,961,782,000 and Rp. 200. Lowest operating costs, lowest CO2 emissions, largest electricity production, and best electricity trading at the PV capacity of 209 kW, 5 WT, and 50 BG with a value Rp 12,428,750, 84,000 kg/year, 882,455 kWh/year, 239,996 kWh, and 132,911 kWh
ANALYSIS OF SOLAR ENERGY POTENTIAL TO ACHIEVE NEARLY ZERO ENERGY COMMUNITY. (CASE STUDY: MALIOBORO STREET, YOGYAKARTA).
Full text linkA number of concrete strategies developed at global, national and local level as a step forward in implementing the sustainability in the community. An interesting concept introduced by the European Commission about buildings that can reach nearly zero energy building with energy efficiency and use the integration of renewable energy sources. This concept then developed into nearly zero Energy Community (nZEC) at community level referring to a group of buildings. Along with the vision of the Malioboro area in the RTBL Final Report on the creation of an environment-friendly and sustainable Malioboro area, research on the potential of solar energy as a PV power source is conducted.This study applies a mapping of the distribution of solar energy potential using 3D building data analysis on Open Street Map (OSM) and Digital Elevation Model (DEM). ArcGIS Pro software was applied to analyze 3D buildings data and geospatial aspects. This study shows a negative correlation between building density and the average solar energy potential with a coefficient of determination R2=0.85. Coverage Degree shows that only by using a solar energy conversion system, the level of coverage by renewable energy can be achieved from 10.25% – 12.56%. However, this value is not enough to achieve energy independence through the nearly Zero Energy Community (nZEC) concept, so a way is needed to achieve it in the future. Significant planning and geometric parameters in relation to performance indicators provide insight as a reference for establishing solar energy-friendly urban planning and architectural design guidelines
ANALYSIS OF TECHNO-ECONOMIC PLANNING OF ON-GRID ROOFTOP PV SYSTEM AT THE GOVERNMENT HOUSE OF PACITAN REGENCY
Full text linkThe geographical condition, which is relatively difficult to reach, electricity and infrastructure has not been maximized, making the electrification ratio in Pacitan Regency one of the lowest on the island of Java at 65%. Pacitan Regency has a promising renewable energy potential, but it has not been maximized for the benefit of the residents. One of them is a solar power plant. If used properly, this alternative energy source can be a solution to meet energy needs in remote areas. As part of the Government's efforts to achieve the new and renewable energy (RE) target of 23% by 2025, the Ministry of Energy and Mineral Resources has issued Minister of Energy and Mineral Resources Regulation Number 26 of 2021 concerning Connected Rooftop Solar Power Plants. On the Electric Power Network, the Holder of a Business License for the Provision of Electric Power for Public Interest (IUPTLU). This Ministerial Regulation is a refinement of the previous regulation to improve the governance and economics of PV, especially PV Rooftop. This regulation is also a step to respond to the existing dynamics and facilitate the public's desire to obtain electricity from renewable energy sources, as well as the desire to contribute to reducing greenhouse gas emissions. This study was conducted to calculate the optimum potential of rooftop photovoltaic power plants in the official residence of the Pacitan Regency Government as an alternative energy source to supply the electricity system from the official residence. This simulation was carried out using the System Advisor Model (SAM) software, considering the technical and economic aspects. Where the economic calculation has two scenarios, namely the profit value based on the Minister of Energy and Mineral Resources Regulation No. 26 of 2021 and the Minister of Energy and Mineral Resources No. 49 of 2018 with total energy produced of 13012 kWh / year with a total of 20 modules installed with a slope of 20o facing north and 1 Inverter and an LCOE value of Rp. 1231.31/kWh, and an NPV of Rp. 117,579,325.50
CO-COMBUSTION EVALUATION OF SPENT BLEACHING EARTH AND COAL: A STUDY CASE IN CEMENT INDUSTRY
Full text linkAs one of largest producers of greenhouse gas (GHG) emission, cement industries are committed to applying alternative ways to reduce the GHG emission level. Co-combustion of spent bleaching earth (SBE) and coal in cement industry is evaluated to reduce dependencies on fossil fuels. Such evaluation is conducted at one of cement plants in Indonesia owned by PT Indocement Tunggal Prakarsa Tbk. Palimanan Unit (PT ITP Palimanan Unit). Combustion in rotary kiln and calciner in two plant units (P9 and P10) were analyzed and compared. The comparison was conducted not only between plant units but also in different combustion operations, i.e., with and without SBE utilization as co-combustion agent. Several parameters consisting of temperature and gas compositions, which include CO, PM, SO2, NO2, CO2, and O2, were analyzed.The study results show insignificant differences in the kiln temperature, while in the calciner, SBE utilization enhances temperature level by up to 40°C compared to the process without SBE. Based on gas composition measurement, slight discrepancies are observed between the two different combustion conditions, although different trends in average absolute value are obtained. NO2 and PM concentrations are found to be slightly higher in the system without SBE, while an opposite trend is observed in SO2 emission. The study also discovered that properties of raw coal and SBE influence the emission trend in the combustion system. This work highlights the potential of SBE co-combustion with coal to be applied in a continuous manner since it provides slightly higher energy conversion while maintaining nearly similar emission level. In addition, the utilization of SBE is found to not cause significant disturbance to the rotary kiln and calciner operations