International Journal of Energy & Environment
The International Journal of Energy & Environment is a scientific journal dedicated to publishing innovative research and comprehensive studies in energy and environment. It provides a platform for academics, researchers, and practitioners to disseminate the latest findings related to renewable energy, energy efficiency, environmental sustainability, and energy and environmental policy development. The journal is published biannually, in June and December. All articles undergo a rigorous peer-review process to guarantee their quality and scientific contribution to advancing energy and environmental studies knowledge. The journal is officially registered under the electronic International Standard Serial Number (e-ISSN: 3083-9718), ensuring its unique digital identity and facilitating global indexing, accessibility, and citation tracking for readers and researchers worldwide.
Combustion and Emission Behavior of Fusel Oil–Gasoline Blends in a Modern Spark-Ignition Engine
The global pursuit of sustainable energy solutions has intensified interest in alternative fuel sources, particularly bio-derived alcohol fuels such as fusel oil. This study investigates the combustion characteristics and emissions mitigation potential of fusel oil–gasoline blends (F10, F20, F30) in a turbocharged gasoline direct injection (GDI) engine under steady-state conditions at 2000 rpm and 40% throttle load. Employing detailed combustion analysis and emissions measurement, the study highlights that blending fusel oil, a renewable by-product of ethanol production, can significantly enhance combustion completeness due to its inherent oxygen content. Methodologically, each fuel blend was tested systematically, ensuring high data reproducibility by averaging results over 200 combustion cycles per test condition, repeated three times. Results showed fusel oil blends accelerated combustion initiation, as evidenced by an earlier peak in-cylinder pressure and rate of heat release. Specifically, HC emissions decreased notably from 125 ppm (F0) to 90 ppm (F30), signifying improved combustion efficiency. Conversely, CO emissions increased from 0.22 mg/kg (F0) to 0.45 mg/kg (F30), indicating localized incomplete combustion due to fusel oil's high latent heat of vaporization. This research uniquely explores fusel oil's viability in turbocharged GDI engines without hardware modifications, contributing valuable insights toward optimizing biofuel integration and reducing harmful emissions, thus supporting sustainable automotive advancements.
Copyright (c) 2025 International Journal of Energy & Environment https://creativecommons.org/licenses/by/4.0
Effect of Oxygenated Turpentine and Alpha-Pinene on Diesel Fuel Physicochemical Properties
The increasing demand for alternative fuels has led to extensive research on bio-additives to enhance fuel performance and reduce environmental impact. This study investigates the effect of turpentine and alpha-pinene, both in pure and oxygenated forms, on the physicochemical properties of diesel fuel. The fuel properties analyzed include density, kinematic viscosity, calorific value, and cetane number. The results indicate that adding bio-additives alters the fuel's characteristics significantly. The density of the test fuels increased compared to diesel (857.72 kg/m³), with the highest density observed in alpha-pinene diesel at 877.06 kg/m³. Kinematic viscosity decreased with the addition of bio-additives, with oxygenated alpha-pinene diesel showing the lowest value of 2.83 mm²/s, compared to 3.32 mm²/s for diesel. The calorific value of turpentine oxygenated diesel was the highest at 44.94 MJ/kg, while alpha-pinene oksigenasi had the lowest at 41.09 MJ/kg. The cetane number decreased in most test fuels, with the lowest value found in turpentine diesel at 63.78, while APD had the highest cetane number of 69.46, surpassing diesel (67.3). Gas chromatography-mass spectrometry analysis revealed significant compositional changes due to oxygenation, with α-pinene content reducing from 61.81% to 32.68% and new oxygenated compounds, such as α-pinene-oxide (6.15%) and trans-verbenol (6.66%), emerging. These findings suggest that turpentine and alpha-pinene bio-additives influence fuel properties differently, with turpentine-oxygenated diesel showing the highest calorific value and alpha pinene-diesel exhibiting the best cetane number. Further research is required to evaluate their impact on engine performance and emissions.
Performance and Emission Characteristics of Biodiesel-Butanol Blends in Variable Engine Speeds and Loads
This study investigates the impact of biodiesel–butanol fuel blends on the performance and emissions of a single-cylinder diesel engine under various loads and speeds. Biodiesel was blended with butanol in volumetric ratios of B100 (pure biodiesel), B90Bu10, B80Bu20, and B70Bu30 to evaluate their effects on specific fuel consumption (SFC) and carbon dioxide (CO₂) emissions. Experimental results indicate that at 25% engine load, the B80Bu20 blend achieved the lowest SFC at 1200 RPM, reducing fuel consumption by 8.5% compared to B100. At 50% load and 1800 RPM, B90Bu10 showed an 11.2% improvement in fuel efficiency over B100. Conversely, higher butanol content (B70Bu30) led to increased SFC at high engine speeds (2400 RPM), likely due to the lower cetane number and heating value of butanol. Regarding emissions, the B80Bu20 blend produced the lowest CO₂ emissions across all engine speeds, achieving a 12.6% reduction at 1800 RPM compared to the B100. This suggests that the moderate addition of butanol enhances combustion efficiency while reducing carbon output. Compared to previous studies that often focused on constant engine load or a single operating speed, this research comprehensively assesses multiple load-speed conditions, highlighting the optimal balance point for fuel blend composition. The findings suggest that B80Bu20 can be a viable alternative fuel for small-scale diesel engines, particularly in applications such as small fishing vessels and rural generators where fuel economy and emission control are critical.
Evaluation of Domestic Wastewater and Constructed Wetland Treatment in Residential Areas
Domestic wastewater management in developing countries often faces challenges due to limited sanitation infrastructure, leading to environmental pollution and public health risks. Constructed wetland (CW) technology, a nature-based solution that utilizes vegetation to filter and decompose pollutants, offers a promising alternative. This study aims to design a domestic wastewater treatment plant (WTP) using a combined CW system, which includes an equalization tank, sedimentation tank, and subsurface flow constructed wetland (SFCW). The case study was conducted in Lam Trieng Madani Housing, Aceh Besar Regency, which lacks adequate wastewater treatment facilities. Laboratory analyses revealed that the Total Suspended Solids (TSS) and total coliform levels in domestic wastewater exceeded the thresholds of Indonesian Regulation No. 68/2016 from the Ministry of Environment and Forestry. The proposed WTP with combined CW technology is expected to offer an effective solution for reducing domestic wastewater pollution in the area. Furthermore, the study contributes to developing and implementing CW-based treatment systems, serving as a model for other residential areas with similar conditions. This approach supports creating sustainable, efficient, and environmentally friendly wastewater management systems, in line with Sustainable Development Goal (SDG) 6: ensuring availability and sustainable management of water and sanitation for all.
Performance Analysis of Diesel Blends with Additives: Impact on Power, Efficiency, and Emissions
This study investigates the performance characteristics of an engine operating with diesel fuel blended with various additives, including turpentine oil, alpha-pinene oil, and oxygenated fuels. Engine performance was evaluated under high load conditions at different engine speeds, focusing on brake power (BP), brake torque (BT), brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), and exhaust gas temperature (EGT). The results indicate that additive-diesel blends generally enhance engine performance compared to conventional diesel fuel. Specifically, at 1,800 rpm, alpha-pinene diesel (APD) achieved the highest BP improvement (7.33%) over diesel, while turpentine diesel (TD) recorded the highest BTE (24%) with a notable reduction in BSFC. The oxygenated additive-diesel blends further improved combustion efficiency, lowering BSFC and EGT values. However, the torque performance varied, with some oxygenated additives showing a slight reduction due to increased oxygen content. The findings suggest that incorporating specific chemical additives can optimize engine efficiency and fuel consumption while reducing exhaust emissions. These results support the potential of alternative fuel formulations in improving engine sustainability and performance.
Emission Characteristics of Oxygenated Diesel Blends Under Varying Engine Speeds
This study investigates the exhaust emission characteristics of various oxygenated diesel blends under different engine speeds and high engine loads. The primary emissions analyzed include carbon dioxide (CO₂), carbon monoxide (CO), and nitrogen oxides (NOₓ), which are key indicators of combustion quality and environmental impact. Experimental tests were performed using pure diesel and its blends with turpentine, alpha-pinene, and oxygenated additives. The results revealed that CO₂ emissions increased with engine speed for all fuels, peaking at 2,400 rpm, where the highest CO₂ level recorded was approximately 11.2% for the APD blend. Notably, the OAPD blend showed the lowest CO₂ emissions across all speeds, indicating less efficient combustion. CO emissions also rose with engine speed, reaching a maximum of 0.65% for diesel at 2,400 rpm. However, the use of oxygenated blends significantly reduced CO emissions—by 0.44% for OTD, and 28.3% for both APD and OAPD—due to improved atomization and fuel-air mixing. NOₓ emissions also increased with engine speed, from 86 ppm at 1,200 rpm to 238 ppm at 2,400 rpm. Blends with turpentine and alpha-pinene exhibited higher NOₓ levels compared to diesel, due to greater premixed combustion and higher in-cylinder peak temperatures. Overall, the findings suggest that oxygenated additives can effectively reduce CO emissions but may increase NOₓ levels, highlighting a trade-off in emission behaviors that must be considered when developing cleaner alternative fuels.
Constructed Wetland as an Alternative for Domestic Wastewater Treatment in Residential Areas
Domestic wastewater management in developing countries still faces obstacles due to limited sanitation infrastructure, which can pollute the environment and endanger public health. One promising solution to overcome this problem is Constructed Wetland (CW), a vegetation-based treatment system that mimics the natural mechanism of wetlands in filtering and decomposing pollutants. This study aims to design a Domestic Wastewater Treatment Plant using Combined Wetland technology, which includes an equalization tank, sedimentation tank, and Subsurface Flow CW. The case study was conducted in Lam Trieng Madani Housing, Aceh Besar Regency, which does not yet have an adequate wastewater treatment system. The technologies selected in this study are equalization tanks, sedimentation tanks, and CW SSF type. CW is a complex technology in processing wastewater and has an aesthetic value that makes CW very suitable for application in rural environments. The planning stages include identifying problems, searching for various literature studies, collecting data, processing data, planning design, and creating a Combination CW and DWTP design. The calculation results in the form of a processing unit design drawing for the equalization tank dimensions are 1.5 m × 0.5 m × 2.3 m with a required land of 0.75 m2, a sedimentation tank with dimensions of 2 m × 1 m × 3.5 m, a required land of 2 m2 and SSFCW dimensions of 19 m × 5 m × 1.2 m with a required land of 95 m2. The total land needed for this planning is 97.75 m2.
Evaluation of Domestic Wastewater Quality in Residential Areas and Treatment Alternatives with Constructed Wetland Technology
Domestic wastewater management in developing countries frequently encounters challenges due to limited sanitation infrastructure, resulting in environmental pollution and public health risks. A promising alternative to mitigate this problem is Constructed Wetland (CW), a vegetation-based system replicating natural wetland processes to filter and degrade pollutants. This study aims to design a Domestic Wastewater Treatment Plant (DWTP) utilizing Combined CW technology, comprising an equalization tank, sedimentation tank, and Subsurface Flow CW. The case study was conducted at Lam Trieng Madani Housing in Aceh Besar Regency, which lacks proper wastewater treatment facilities. Laboratory tests revealed that Total Suspended Solids (TSS) and total coliform levels in domestic wastewater at this site exceeded the standards outlined in the Indonesian Minister of Environment and Forestry Regulation Number 68 of 2016. Implementing the Combined CW system is proposed as an effective solution to reduce environmental pollution from domestic wastewater in the area. Additionally, the findings offer insights into CW-based wastewater treatment technology, potentially serving as a reference for similar contexts. Consequently, this research contributes toward developing a sustainable, efficient, and environmentally friendly wastewater treatment system. Furthermore, it supports achieving Sustainable Development Goal 6, ensuring universal availability and sustainable management of water and sanitation.
Carbon Footprint Reduction Potential of On-Grid Renewable Microgrids
Using renewable energy-based microgrids in on-grid systems has great potential in reducing carbon emissions and increasing energy efficiency. This study analyzes the impact of renewable energy integration on microgrids using HOMER Pro simulation. The simulation results show that with a combination of 500 kW of solar power, 300 kW of wind turbines, and 1 MWh of battery storage systems, microgrids can replace up to 60% of electricity needs that previously depended on fossil fuels. The reduction in carbon emissions reaches 40%, from 1,200 tons per year in conventional systems to around 720 tons per year in microgrid systems. In addition to environmental benefits, the implementation of microgrids also provides economic benefits by reducing fuel consumption by up to 500,000 litres per year, which has an impact on reducing operational costs by up to 30%. This system also increases energy efficiency by up to 85%, especially with energy storage technology that optimises renewable electricity utilization. The results show that the higher the penetration of renewable energy in the microgrid, the greater the operational cost efficiency achieved, with fuel savings reaching 500,000 litres per year and operational cost reductions of up to 20% in scenarios with renewable energy penetration of 60–70%. Policy support such as feed-in tariffs (FiT) and tax incentives are essential to accelerate the adoption of renewable energy-based microgrids. With continued development, microgrids can be a strategic solution in transitioning to a more environmentally friendly, efficient, and sustainable energy system.
Copyright (c) 2025 International Journal of Energy & Environment
Cycle-to-Cycle Variation in Diesel Engines Using Water-Diesel-Butanol Blended Fuels
This study investigates the cycle-to-cycle variations in cylinder pressure. It indicates the mean adequate pressure (IMEP) of a single-cylinder diesel engine fueled with water-in-diesel-butanol (WDBu) emulsified blends at various engine loads. Experiments were conducted at a constant engine speed of 3,000 rpm under 50% load, using five different fuel types: pure diesel (D), water-in-diesel (W5D), and three WDBu blends W5DBu5, W5DBu10, and W5DBu15. Results revealed that the highest peak cylinder pressure (Pmax) of 89.10 bar was recorded with W5DBu10, while the lowest (79.03 bar) was observed with W5DBu15. The maximum pressure variation was most stable for W5D with a %RSD of 1.23% and least stable for W5DBu10 with a %RSD of 2.21%. Notably, the W5DBu5 blend showed a moderate Pmax variability of 8.95 bar and produced the most inconsistent pressure across 100 cycles. Regarding IMEP cyclic variation, the coefficient of variation (COVimep) was used to assess combustion stability at engine loads of 20%, 35%, and 50%. At 50% load, W5DBu5 exhibited the lowest COVimep of 1.10, indicating superior cyclic stability compared to diesel, which showed the highest COVimep of 1.26. The findings suggest that a WDBu5 blend offers an optimal balance between performance and stability, positioning it as a promising alternative fuel for compression ignition engines. This study contributes valuable insights for enhancing combustion consistency in alternative fuel applications.
Cylinder Pressure and Heat Release Analysis of Diesel-Butanol Blends at High Engine Load
This study investigates the impact of butanol-water blended fuels on the combustion characteristics of a diesel engine, focusing on cylinder pressure and heat release rate under high engine speed (3,000 rpm) and varying load conditions (20%, 35%, and 50%). With increasing butanol concentrations, the blends tested include W5DBu5, W5DBu10, and W5DBu15. Results show that higher butanol content increases peak in-cylinder pressure and enhances thermal performance. At 35% load, W5DBu15 recorded the highest peak pressure compared to other blends, indicating improved combustion due to better air-fuel mixing. At 50% load, the peak in-cylinder gas temperature reached nearly 2,000°C for all blends, slightly lower than pure diesel, suggesting effective NOx reduction from water cooling effects. The heat release rate analysis reveals a higher premixed combustion phase for all blends, with W5DBu15 showing the most significant increase. This increase is attributed to a longer ignition delay caused by the lower cetane number of butanol. Moreover, the heat release pattern of all blends closely resembles that of base diesel, ensuring compatibility without engine harm. The study confirms that diesel-butanol-water emulsions improve thermal efficiency and combustion behaviour without compromising engine safety, especially at medium to high loads and speeds.
Lifecycle Analysis of Biocoke Fuel from EFB Waste for Sustainable Energy Production
Biocoke from Empty Fruit Bunch (EFB) waste has the potential to be an alternative fuel that is more environmentally friendly than coal and other biomass. This study analyzes the environmental impact, energy efficiency, and economic aspects of biocoke based on Life Cycle Impact Assessment (LCIA) and financial analysis. The results show that biocoke has CO₂ emissions of 50 kg, much lower than coal, which reaches 120 kg CO₂ and other biomass of 80 kg CO₂. In addition, the energy consumption for biocoke production is only 1,500 MJ, or 50% lower than that of coal, which requires 3,000 MJ. In terms of economy, the production cost of biocoke is recorded at 30 USD/MWh, slightly higher than coal (25 USD/MWh) and biomass (28 USD/MWh). However, its market price of 50 USD/MWh makes it competitive. Biocoke has the highest energy efficiency, 80% higher than coal (75%) and biomass (70%). Sensitivity analysis shows that increasing the efficiency of the pyrolysis process from 70% to 85% can reduce production costs by 20% and increase the sustainability of biocoke as an alternative fuel. With policy incentives and technology optimization, biocoke has the potential to replace fossil fuels and support a sustainable energy transition.
Heavy Metal Contamination in Biomass-Based Fuels: Risks and Mitigation Strategies
Biomass is a potential renewable energy source to reduce dependence on fossil fuels. However, heavy metal contamination in biomass, especially from agricultural waste, poses environmental and health risks. This study analyzed the heavy metal content in various types of biomass, including oil palm empty fruit bunches (EFB), rice husk, wood pellets, and biocoke, and evaluated mitigation strategies that can be applied. The results showed that EFB had the highest heavy metal content, with concentrations of Pb (2.5 mg/kg), Cd (1.8 mg/kg), As (0.9 mg/kg), and Hg (0.5 mg/kg), compared to wood pellets which had lower levels (Pb: 0.8 mg/kg, Cd: 0.3 mg/kg, As: 0.2 mg/kg, Hg: 0.1 mg/kg). Several mitigation strategies have been shown to be effective in reducing heavy metal content. The washing method with a weak acid solution can reduce Cd content by up to 40% and As by up to 35%, while adsorption with biochar can reduce Pb levels by up to 50% and Hg by up to 60%. In addition, the volatility of heavy metals increases significantly at temperatures above 600°C, which increases the risk of hazardous air emissions. Overall, most biomass samples are still within safe limits according to EN 14961 and EPA standards, although some agricultural wastes are close to the threshold. Therefore, strict monitoring and broader mitigation strategies are needed to ensure that biomass remains safe for use as fuel. Implementation of appropriate technology will improve the sustainability of biomass energy and reduce negative impacts on the environment and human health.
Sustainability Assessment of Biocoke as an Alternative Fuel: A Comparative Study
The increasing environmental concerns and the need for sustainable energy sources have driven research into alternative fuels. This study evaluates the sustainability of biocoke as an alternative fuel by comparing its characteristics, emissions, economic feasibility, and combustion efficiency with conventional fuels such as coal-based coke and charcoal. The proximate and ultimate analysis revealed that biocoke contains 75% fixed carbon, lower than coal-based coke (85%) but higher than charcoal (70%). Its heating value of 26 MJ/kg is comparable to conventional fuels, making it a viable alternative. Additionally, biocoke has a lower ash content (5%) than coal-based coke (10%), reducing solid waste generation during combustion. Emission analysis indicated that biocoke reduces CO₂ emissions by 25%, producing 150 kg/ton compared to 200 kg/ton from coal-based coke. Furthermore, SO₂ and NOₓ emissions from biocoke are significantly lower, attributed to its lower sulfur and nitrogen content. From an economic perspective, biocoke’s production cost is currently 150 USD/ton, higher than 100 USD/ton for coal-based coke but expected to decrease with technological advancements. Combustion efficiency tests showed biocoke’s efficiency at 88%, slightly lower than 92% for coal-based coke but superior to charcoal at 80%. Biocoke presents a promising alternative fuel with lower emissions, comparable heating value, and high combustion efficiency, making it suitable for industrial applications. However, optimization of production processes and policy support are essential to improve its economic feasibility and widespread adoption. Future research should explore large-scale applications and co-firing potential to enhance energy efficiency further
Optimizing Biodiesel-Butanol Blends for Low CO₂ Emissions and Fuel Efficiency in Diesel Engines
This study investigates the impact of various biodiesel–butanol fuel blends on CO₂ emissions and brake-specific fuel consumption (BSFC) under different engine speeds and load conditions. Experiments were conducted using blends of biodiesel (B5, B10, B15) combined with butanol concentrations of 5% and 10% (Bu5, Bu10) at engine speeds of 1200, 1800, and 2400 rpm, across load levels of 25%, 50%, and 75%. The results indicate that both CO₂ emissions and BSFC are significantly influenced by fuel composition, engine load, and speed. Notably, blends such as B5Bu5 and B10Bu5 showed the lowest CO₂ emissions at high engine loads, reaching values as low as 0.2% at 75% load and 1200 rpm, suggesting enhanced combustion efficiency. At higher engine speeds, CO₂ emissions increased, especially at mid-load conditions, with B10Bu10 recording a peak emission of 4.2% at 2400 rpm and 50% load. Regarding BSFC, the B15Bu10 blend consistently demonstrated superior fuel efficiency, especially under full-load conditions, with the lowest recorded BSFC of 165 g/kWh at 25% load and 1200 rpm. Conversely, blends with excessive butanol content exhibited higher BSFC at low loads, indicating incomplete combustion. These findings highlight the importance of optimizing biodiesel–butanol ratios based on specific engine operating conditions. The study contributes valuable insights into cleaner alternative fuels, supporting efforts to reduce carbon emissions and improve energy efficiency in diesel engine systems.
Comprehensive Review on Renewable Energy Initiatives at Universiti Malaysia Pahang Al-Sultan Abdullah
The transition to renewable energy is crucial in achieving sustainability and carbon neutrality. This study reviews the renewable energy initiatives implemented at Universiti Malaysia Pahang Al-Sultan Abdullah (UMPSA), including solar, wind, hydro, and biodiesel energy systems. The findings reveal that UMPSA has installed a total solar energy capacity of 3.58 MWp, supplying up to 75% of the campus’s electricity needs. Solar energy installations generated 269,318 kWh between 2022 and 2023, significantly reducing reliance on fossil fuels. Wind energy has also been integrated, with wind turbines generating up to 22 kW since 2012, supporting campus operations and research activities. Additionally, small-scale hydro systems, including the Sea-Lite seawater electrolysis and pico hydro projects, contributed 1,116.9 kWh of electricity annually. Furthermore, the biodiesel initiative has produced 2,640 litres annually, generating 10,150 kWh of energy while promoting waste-to-energy conversion. These efforts align with Malaysia’s 2050 carbon neutrality goal and demonstrate the potential of academic institutions in leading the renewable energy transition. The study concludes that UMPSA’s integrated renewable energy systems provide significant environmental, economic, and educational benefits. Future recommendations include expanding renewable energy projects, enhancing efficiency, and fostering collaborations with industry and government to strengthen Malaysia’s green energy agenda. The results of this study highlight the role of universities in promoting sustainable energy solutions and provide a model for similar institutions to adopt renewable energy strategies.
Environmental Impacts of Biocoke Fuel Production from Agricultural Waste
Biocoke fuel, derived from agricultural waste, is an emerging alternative to fossil fuels due to its lower environmental impact. This study investigates the ecological effects of biocoke production from Empty Fruit Bunches (EFB), rice husks, and corn stalks. The research focuses on biocoke yield efficiency, air emissions, heavy metal contamination, and life cycle assessment (LCA). The highest biocoke yield was observed at 400°C, with EFB achieving 65%, corn stalks 60%, and rice husks 55%. Gas emissions analysis showed CO2 emissions ranging between 1100–1200 ppm, approximately 50% lower than conventional coal combustion. Heavy metal analysis detected trace amounts of cadmium (Cd), lead (Pb), and arsenic (As), remaining within safe limits but necessitating proper disposal of biocoke ash. The LCA results indicated a 50–70% reduction in greenhouse gas emissions when substituting coal with biocoke, with the lowest carbon footprint recorded for EFB-based biocoke at 30 kg CO2 equivalent, compared to coal at 100 kg CO2 equivalent. While biocoke presents environmental advantages, concerns over large-scale production, biomass sustainability, and potential soil degradation require further study. Future research should focus on optimizing production processes, improving emissions control, and assessing industrial applications. Overall, this study highlights the potential of biocoke as a sustainable energy source, contributing significantly to carbon emission reduction and renewable energy development.
Techno-Economic Assessment of Renewable Energy Integration in On-Grid Microgrids
Integrating renewable energy sources into on-grid microgrids is a promising approach to enhance energy efficiency, reduce greenhouse gas emissions, and improve economic feasibility. This study performs a techno-economic assessment using HOMER Pro to optimize the configuration of a hybrid microgrid incorporating solar photovoltaic (PV), wind turbines, biomass generators, and battery storage. The optimal system comprises 500 kW of solar PV, 300 kW of wind turbines, 200 kW of biomass generation, and 400 kWh of battery storage. The economic evaluation indicates a Levelized Cost of Energy (LCOE) of 0.08 USD/kWh, a Net Present Cost (NPC) of 1.2 million USD, and a Return on Investment (ROI) of 18.5%, demonstrating its financial viability. Sensitivity analysis reveals that a 20% increase in fuel prices leads to a 10% rise in LCOE. In comparison, a 15% reduction in renewable technology costs decreases LCOE by 12%, highlighting the economic stability of the system. Additionally, the environmental analysis shows that the microgrid reduces CO2 emissions by approximately 1,780 tons annually, contributing significantly to sustainability efforts. The financial projection further indicates that the system reaches a break-even point within 7 years, generating a positive net cash flow. These findings suggest that renewable-integrated microgrids are technically feasible and economically viable for on-grid applications. Future research should focus on real-world implementation and policy support to enhance the adoption of such systems. This study provides valuable insights for stakeholders, policymakers, and investors aiming to transition towards cleaner and more sustainable energy solutions.
Heavy Metal Analysis in Biocoke Fuel Derived from Empty Fruit Bunch (EFB) Waste
This study aims to analyze the effect of carbonization temperature on the concentration of heavy metals in biocoke produced from oil palm empty fruit bunches (EFB). EFB samples were carbonized at three different temperatures, namely 300°C, 400°C, and 500°C, to evaluate the effectiveness of the process in reducing the content of heavy metals such as Pb, Cd, Zn, Cr, Cu, Ni, and Hg. The results showed that increasing the carbonization temperature significantly reduced the concentration of heavy metals in biocoke products. The concentration of Pb decreased by 44% from 2.15 mg/kg at 300°C to 1.20 mg/kg at 500°C. Similarly, Cd decreased by 47% from 0.85 mg/kg to 0.45 mg/kg, while Zn decreased by 37% from 15.20 mg/kg to 9.60 mg/kg. ANOVA statistical analysis strengthens this finding by showing significant F-values ​​for Pb (12.35 with p=0.001), Cd (15.20 with p=0.000), and Zn (10.50 with p=0.003). Based on these findings, applying high carbonization temperature, especially 500°C, is recommended to minimize the content of heavy metals, thus producing a more environmentally friendly biocoke that is safe to use as an alternative fuel. This study provides important insights for developing renewable energy from biomass in Indonesia.
Optimization of On-Grid Microgrid Systems Using HOMER Pro: A Case Study Approach
This research presents a comprehensive optimization of on-grid microgrid systems using HOMER Pro software, employing a detailed case study approach. The main objective was to explore optimal configurations involving solar photovoltaic (PV), wind turbines, battery storage, and integration with the existing grid, considering local resource availability, economic parameters, and regulatory constraints. The study highlighted the significance of effectively integrating renewable energy sources to achieve sustainable and economically viable energy solutions. Simulation and optimization results demonstrated that a hybrid configuration of solar PV, wind turbines, battery storage, and grid integration significantly reduced operational costs and improved renewable energy penetration. Specifically, the optimized hybrid system achieved a renewable energy penetration rate of approximately 72%, considerably decreasing dependency on conventional energy sources. Economically, the configuration resulted in a Net Present Cost (NPC) of 350,000 USD and a Levelized Cost of Energy (LCOE) of 0.18 USD/kWh, representing a 30% cost saving compared to the conventional grid-only system with an NPC of 500,000 USD and an LCOE of 0.26 USD/kWh. Additionally, sensitivity analysis highlighted that battery storage is crucial in ensuring system reliability, particularly during peak load hours. These findings underline the effectiveness of HOMER Pro for developing economically feasible and sustainable energy solutions adaptable to diverse geographic and regulatory contexts.