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International Journal of Renewable Energy Development
Published by Universitas Diponegoro
ISSN : 22524940     EISSN : 27164519     DOI : https://doi.org/10.14710/ijred
Core Subject : Science,
Chemistry Energy
The scope of journal encompasses: Photovoltaic technology, Solar thermal applications, Biomass, Wind energy technology, Material science and technology, Low energy Architecture, Geothermal energy, Wave and Tidal energy, Hydro power, Hydrogen Production Technology, Energy Policy, Socio-economic on energy, Energy efficiency and management The journal was first introduced in February 2012 and regularly published online three times a year (February, July, October).
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 573 Documents
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Experimental Study of Rice Husk Fluidization Without a Sand Bed Material on a Bubbling Fluidized Bed Gasifier Abeth Novria Sonjaya; Kania Safitri; Adi Surjosatyo
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.46068

Abstract

This study aimed to determine the effect of rice husk fluidization and variation in the equivalence ratio of bubbling fluidized bed gasifiers without sand bed materials. It also aimed to improve the fluidization quality by reducing the diameter of rice husks. Therefore, the bulk density increases, whereas voidage decreases, both of which are the main parameters for improving the quality of fluidization in solid particles. Experiments were carried out at a velocity of 0.82 m/s, by varying the equivalent ratios ranging from 0.20 to 0.35, and analyzing the syngas composition, cold gas and carbon conversion efficiencies, lower heating value, and temperature distribution. An equivalence ratio of 0.30 was obtained for a bubbling fluidized gasifier with syngas compositions of 7.415%, 15.674%, 3.071%, 17.839%, and 56.031% for H2, CO, CH4, CO2, and N2, respectively. Under these conditions, we obtained cold gas and carbon conversion efficiencies and a lower heating value of 31.340%, 37.120%, and 3.881 MJ/Nm3, respectively.
Statistical Analysis on The Near-Wake Region of RANS Turbulence Closure Models for Vertical Axis Tidal Turbine Muhammad Wafiuddin Abd Rahim; Anas Abdul Rahman; Ayu Abdul-Rahman; Muhammad Izham Ismail; Mohd Shukry Abdul Majid; Nasrul Amri Mohd Amin
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.48380

Abstract

The flow field in the near wake region (up to six turbine diameters downstream) of a tidal current turbine is strongly driven by the combined wake of the device support structure and the rotor. Accurate characterisation of the near-wake region is important, but it is dominated by highly turbulent, slow-moving fluid. At present, limited number of research has been undertaken into the characterisation of the near-wake region for a Vertical Axis Tidal Turbine (VATT) device using the Reynolds Averaged Navier Stokes (RANS) model in the shallow water environment of Malaysia. This paper presents a comprehensive statistical analysis using the Mean Absolute Error (MEA), Mean Squared Error (MSE) and Root Mean Squared Error (RMSE) on the near-wake region for shallow water application by comparing numerical solutions (i.e., different types of RANS turbulence models using Ansys Fluent) with published experimental data. Seven RANS turbulence models with a single VATT, represented by using a cylindrical object, were employed in the preliminary study. The statistical analysis performed in this study is essential in exploring and giving a detailed understanding on the most suitable RANS turbulence model to be improved, specifically on its near-wake region. In this study, the near wake region is defined as D ≤ 6, where D is the device diameter. The analysis shows that the RANS numerical solutions are unable to accurately replicate the near-wake region based on large statistical errors computed. The average RMSE of near-wake region at z/D = [2, 3, 4, 6] are 0.5864, 0.4127, 0.4344 and 0.3577 while the average RMSE at far-wake region z/D = [8, 12] are 0.2269 and 0.1590, where z is the distance from the cylindrical object along the length of domain. The statistical error values are found to decrease with increasing downstream distance from a cylindrical object. Notably, the standard k–ε and realizable k–ε models are the two best turbulent models representing the near-wake region in RANS modelling, yielding the lowest statistical errors (RMSE at z/D = [2, 3, 4, 6] are 0.5666, 0.4020, 0.4113 and 0.3455) among the tested parameters
Techno-Economic Assessment of a 100 kWp Solar Rooftop PV System for Five Hospitals in Central Southern Thailand Rawit Khamharnphol; Ismail Kamdar; Jompob Waewsak; Somphol Chiwamongkhonkarn; Sakrapee Khunpetcha; Chuleerat Kongruang; Yves Gagnon
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.46864

Abstract

This paper presents a techno-economic assessment of a 100 kWp solar rooftop photovoltaic (PV) system at five hospitals in central southern Thailand.  The system encompasses 100 kWp PV panels, 100 kW grid-tied inverters and balance of system (BOS) under the grid code of the Provincial Electricity Authority (PEA).  The latest PV technology of bifacial mono-crystalline solar panels, inverters and BOS were simulated along with the Meteonorm 7.3 database using the PVsyst simulation toolkit with different tilt angles, orientations, solar radiations and ambient temperature.  The technical aspects of solar rooftop PV power generation systems include the annual energy output and the performance ratio (PR) under IEC standard.  Further, an economic analysis of the model was examined using a cost benefit analysis (CBA) and various assumptions.  Four main financial criteria, i.e., benefit cost ratio (BCR), net present value (NPV), internal rate of return (IRR), and payback period (PBP) were evaluated under three different scenarios: (1) self-consumption scheme, (2) feed-in tariff (FiT) scheme, and (3) private power purchase agreement (PPA) scheme.  Finally, the levelized cost of energy (LCOE) was also calculated.  The results reveal that the Takua Thung hospital is characterized by the maximum average global horizontal irradiation (GHI) and the maximum annual produced energy of 199 kWh/m2 and 164.8 MWh/year, respectively.  The PR calculated for all hospital sites is above 85%. The outcomes of the financial analysis show that the optimum scenarios are PPA and FiT schemes.  The LCOE analysed in this study indicates that the Takua Thung hospital site has the lowest LCOE at 2.47 THB/kWh (0.07 USD/kWh).  This research confirms the potential for hospitals and stakeholders in central southern Thailand for investments in solar rooftop PV systems
Techno-Economic Analysis of Co-firing for Pulverized Coal Boilers Power Plant in Indonesia Zainal Arifin; Visang Fardha Sukma Insani; Muhammad Idris; Kartika Raras Hadiyati; Zakie Anugia; Dani Irianto
International Journal of Renewable Energy Development Vol 12, No 2 (2023): March 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.48102

Abstract

The utilization of co-firing (coal-biomass) in existing coal-fired power plants (CFPPs) is the fastest and most effective way to increase the renewable energy mix, which has been dominated by pulverized coal (PC) boilers, particularly in the Indonesian context. This study aims to investigate the technical and economic aspects of co-firing by conducting a pilot project of three PC boiler plants and capturing several preliminary figures before being implemented for the entire plants in Indonesia. Various measured variables, such as plant efficiency, furnace exit gas temperature (FEGT), fuel characteristic, generating cost (GC), and flue gas emissions, were identified and compared between coal-firing and 5%-biomass co-firing. The result from three different capacities of CFPP shows that co-firing impacts the efficiency of the plant corresponding to biomass heating value linearly and has an insignificant impact on FEGT. Regarding environmental impact, co-firing has a high potential to reduce SO2 and NOx emissions depending on the sulfur and nitrogen content of biomass. SO2 emission decreases by a maximum of 34% and a minimum of 1.88%. While according to economic evaluation, the average electricity GC increases by about 0.25 USD cent/kWh due to biomass price per unit of energy is higher than coal by 0.64×10-3 USD cent/kcal. The accumulation in the one-year operation of 5%-biomass co-firing with a 70% capacity factor produced 285,676 MWh of green energy, equal to 323,749 tCO2e and 143,474 USD of carbon credit. The biomass prices sensitivity analysis found that the fuel price per unit of energy between biomass and coal was the significant parameter to the GC changes.
Thermal Performance of Double Pass Solar Air Heater With Tubular Solar Absorber Nassr Fadhil Hussein; Sabah T Ahmed; Ali L Ekaid
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.46328

Abstract

In this investigation, the effect of replacing the conventional solar absorber with a new solar absorber on the thermal performance of a double-pass solar air heater has been studied experimentally and numerically.  Three configurations have been introduced, the first configuration is a double pass solar air heater with a flat plate solar absorber (DPSAHWFP) for the aim of comparison, and the second configuration is a double pass solar air heater with a tubular absorber that includes a set of tubes which are fitted perpendicularly to the direction of airflow (DPSAHWT-1),  and the third configuration is double-pass solar air heater with a tubular absorber that involves set of tubes which are fitted in parallel to the direction of airflow (DPSAHWT-2). The experiments have been carried out under indoor conditions at a constant heat flux equal to 1000 W/m2 and different air mass flow rates (0.01– 0.03 kg/s). The results revealed that the air mass flow rate has a substantial impact compared to the rise in air temperature, hence, the thermal performance of solar air heater is directly proportional to increase air mass flow rate. In addition, the experimental and numerical outcomes indicated that for all air flow rates. The (DPSAHWT-2) offers higher thermal performance as compared to other models, where the maximum effective efficiency has been obtained at 0.03 kg/s equal to 80.9 %. Moreover, (DPSAHWT-2) is more efficient than DPSAHWFP and DPSAHWT-1 by 4.2 % and 9.8 % respectively.
An investigation of the Steady-State and Fatigue Problems of a Small Wind Turbine Blade Based on the Interactive Design Approach Khalil Deghoum; Mohammed T Gherbi; Muhsin J Jweeg; Hakim S Sultan; Azher M Abed; Oday I Abdullah; Necib Djilani
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.48616

Abstract

A wind turbine blade is an essential system of wind energy production. During the operation of the blade, it is subjected to loads resulting from the impact of the wind on the surface of the blade. This leads to appear large deflections and high fatigue stresses in the structure of blades. In this paper, a 5 kW horizontal axis wind turbine blade model is designed and optimized using a new MATLAB code based on blade element momentum (BEM) theory.The aerodynamic shape of the blade has been improved compared with the initial design, the wind turbine power has been increased by 7% and the power coefficient has been increased by 8%.  The finite Element Method was used to calculate the loads applied to the blade based on Computational Fluid Dynamics (CFD) and BEM theory.High agreements were obtained between the results of both approaches (CFD and BEM).The ANSYS software was also used to simulate and optimize the structure of the blade by applying variable static loads 3.3, 6, and 8.3 kg and compared the results with the experimental results. It was reduced the maximum deflectionswith 37%, 42.85%, and 42.61% when using CFRP material and 4.5%, 15.45%, and 16.19% for GFRP material that corresponds to the applied forces. Based on the results, the mass of the optimized model decreased by 47.86% for GFRP and 71.24% for CFRP. IEC 61400.2 standard was used to estimate thefatigue loads, damage, blade life prediction, and verify blade safety usinga Simplified Load Model(SLM) and FAST software. It was found that the blade will be safe under extreme wind loads, and the lifetime of the wind blade (GFRP) is 5.5 years and 10.25 years,according to SLM and FAST software, respectively. At the same time, the lifetime of the wind blade (CFRP)is more than 20 years, according to the two applied methods.
Effects of Injection Strategies on Mixture Formation and Combustion in a Spark-Ignition Engine Fueled with Syngas-Biogas-Hydrogen Thanh Xuan Nguyen-Thi; Thi Minh Tu Bui
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.49368

Abstract

The paper presents the effects of blend injection and dual injection strategies on mixture formation and combustion of syngas-biogas-hydrogen fueling engine working in the solar-biomass hybrid renewable energy system. The research was performed by simulation method on a retrofitted Honda GX200 spark-ignition engine. The results show that at the end of the compression process, in the case of blend injection of 50% syngas-50% biogas, the fuel-rich zone was positioned on the top of the combustion chamber, whereas in the case of dual injection, this zone was found on the top of the piston. In the case of 50% syngas-50% hydrogen supplied, at the end of the compression process, the fuel-rich area observed on the top of the piston with slightly deflected towards the inlet port in both cases of blend and dual injection. When shifting from blend injection mode to dual injection mode, in the case of 50% syngas-50% biogas fueling engine, the mean temperature of the exhaust gas decreased from 1208 K to 1161 K and the NOx concentration decreased from 1919 ppm to 1288 ppm. In the case of a 50% syngas-50% hydrogen fueling engine, the mean exhaust gas temperature decreases from 1283 K to 1187 K leading to a decrease in NOx concentration from 3268 ppm to 2231 ppm. The dual injection has the advantage of lower NOx emission, whereas the blend injection has the advantage of higher efficiency
Monitoring of Heat Flux Energy in the Northernmost Part of Sumatra Volcano Using Landsat 8 and Meteorological Data Muhammad Yanis; Nasrullah Zaini; Isra Novari; Faisal Abdullah; Bondan Galih Dewanto; Muhammad Isa; Marwan Marwan; Muzakir Zainal; Abdurrahman Abdurrahman
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.47048

Abstract

Geothermal energy, as a part of green and renewable energy, has been widely developed in the world to replace the current conventional fossil energy. Peut Sagoe is an active volcano in the northern part of Sumatra. The volcanic mountain has not been completely explored for geothermal and energy reserves study. This is due to the volcano locates in a high topography and surrounded by dense tropical forest, which makes it challenging to deploy geophysical instruments in the area. The Landsat 8 thermal infrared and meteorological data from 2013 – 2020 were used to estimate the energy resources by calculating the radiative heat flux (RHF) and measuring the energy lost annually through the heat discharge rate (HDR). We also used the normalized differential vegetation index (NDVI) for vegetation analysis, and estimation of its emissivity data. The mono-window algorithm was used to calculate the land surface temperature (LST). The Stefan–Boltzmann equation was utilized to analyze thermal infrared data for RHF, and ambient temperature and relative humidity data were acquired from the Indonesian Meteorological Agency (BMKG) database. The results showed that low vegetation values and high LST of 25°C–35°C were found in crater areas, which indicate the underground thermal activities of the mountain. It demonstrates that the maximum RHF values were 55 W/m2 in 2013 and 37 W/m2 in 2020. The HDR data were calculated by applying 15% of the RHF data, and the amounts of energy lost were 132.5 MWe and 64.5 MWe in 2013 and 2015 respectively. It increased to 186.4 MWe in 2017 and 89 MWe in 2020. Based on these predicted results, we conclude that the combination of thermal infrared imagery of Landsat 8 and meteorological data is an effective approach in estimating geothermal energy potential and energy loss of volcanoes situated in remote areas
Effect of Pretreatment and C/N Ratio in Anaerobic Digestion on Biogas Production from Coffee Grounds and Rice Husk Mixtures Budiyono Budiyono; Hashfi Hawali Abdul Matin; Ihzani Yulistra Yasmin; Iwang Septo Priogo
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.49298

Abstract

Indonesia has great potential in producing large quantities of renewable energy sources, such as biomass. Biogas is a renewable energy source produced from biomass. It is can be developed in agricultural countries producing rice and coffee, where a large amount of waste is produced in the form of rice husks and coffee grounds. This study examined the effect of physiochemical pretreatment and the C/N ratio on biogas production using coffee grounds and rice husk mixtures. Physical pretreatment was conducted by grinding the mixture up to 50 mesh size, followed by chemical pretreatment by soaking the mixture in 3% KOH; moreover, the variation in the C/N ratio was set at 25 and 30. Anaerobic bacteria were acquired from rumen fluid. The ratio of the coffee ground material, rice husks, and rumen fluid was 1:1:1. This research was conducted in duplicate under batch conditions at ambient temperature (25–35 oC) with a digester volume of 1.5 L. Biogas productivity was measured every 2 d for 60 d. The experimental results indicated that biogas production with a C/N ratio of 30 was 13.3–66.5% higher than that with a C/N ratio of 25. The inclusion of physical pretreatment at a C/N ratio of 30 increased biogas production by up to 31.3%. Moreover, the inclusion of a chemical pretreatment at a C/N ratio of 30 resulted in 30.3% higher biogas production. The kinetics model of biogas production showed that a C/N ratio of 30 with physical and alkaline pretreatment can produce maximum biogas yields of 6,619 mL and 6,570 mL, respectively. Overall, both pretreatments sequentially increased the biogas production significantly.
An Effect of Wind Veer on Wind Turbine Performance Undarmaa Tumenbayar; Kyungnam Ko
International Journal of Renewable Energy Development Vol 12, No 1 (2023): January 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.47905

Abstract

An investigation was performed to identify the wind veer impact on wind turbine power performance at a wind farm located on Jeju Island, South Korea. A 2 MW wind turbine was used as a test turbine. An 80 m-tall met mast was located 220 m away from the test wind turbine and a ground lidar was installed close to the met mast. The wind veer conditions were divided into four types: veering in upper and lower rotor (VV), veering in upper and backing in lower rotor (VB), backing in upper and lower rotor (BB) and backing in upper and veering in lower rotor (BV). The frequency of the four types was identified at the wind farm. The characteristics of wind veer was analysed in terms of diurnal variation and wind speed. In addition, the power curves of the four types were compared with that under no veer condition. Also, the power deviation coefficient (PDC) derived from the power outputs was calculated to identify the effect of the four types on the turbine power performance. As a result, the frequencies of the types, VV, VB, BB and BV were 62.7 %, 4.9 %, 9.2 % and 23.1 %, respectively. The PDCs for the types VV and BV were 3.0 % and 4.2 %, respectively, meaning a power gain while those for the types VB and BB were -2.9 % and -3.9 %, respectively, meaning a power loss.

Page 48 of 58 | Total Record : 573

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