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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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Outstanding Photo-bioelectrochemical Cell by Integrating TiO2 and Chlorophyll as Photo-bioanode for Sustainable Energy Generation Christwardana, Marcelinus; Septevani, Athanasia Amanda; Yoshi, Linda Aliffia
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.41722

Abstract

Photosynthesis is a technique for converting light energy into chemical energy that is both efficient and sustainable. Chlorophyll in energy-transducing photosynthetic organisms is unique because of their distinctive structure and composition. In photo-bioelectrochemical research, the chlorophyll's quantum trapping efficiency is attractive. Chlorophyll from Spirulina platensis is demonstrated to communicate directly with TiO2-modified Indium Thin Oxide (ITO) to generate electricity without the use of any mediator. TiO2-modified ITO with a chlorophyll concentration of 100 % generated the greatest power density and photocurrent of approximately 178.15 mW/m2 and 596.92 mA/m2 from water oxidation under light among all the other materials. While the sensitivity with light was 0.885 mA/m2.lux, and Jmax value was 1085 mA/m2. Furthermore, the power and photocurrent density as a function of chlorophyll content are studied. The polarizability and Van der Waals interaction of TiO2 and chlorophyll are crucial in enhancing electron transport in photo-bioelectrochemical systems. As a result, this anode structure has the potential to be improved and used to generate even more energy.
Numerical Study of The Effect of Penstock Dimensions on a Micro-hydro System using a Computational Fluid Dynamics Approach Putra, Yoga Satria; Noviani, Evi; Muhardi, Muhardi
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.42343

Abstract

The performance of a micro-hydro system needs always to be improved so that the electrical power produced can be more optimal. This article aims to study numerically the effect of penstock dimensions on the potential of electrical energy in a micro-hydro system using a computational fluid dynamics (CFD) approach. The study of the effect of dimensions on the performance of a hydropower system is still quite rare. In this paper, the impact of dimensions on the micro-hydro system has been analysed by constructing thirty simulations of water flow in the penstock consisting of five variations of penstock slope ( and ) for six penstock diameter variations (  m,  m,  m,  m,  m, and  m). The simulation was built using the open-source CFD software OpenFOAM which applies the finite volume method to solve the Navier-Stokes equation as a flow model. The simulated water velocity profile is then validated against the velocity profile of the analytical solution (power-law) for turbulent flow in the pipe. Energy loss analysis on the penstock has been carried out to determine the cause of the energy loss in the penstock characterised by loss coefficient . An enormous  value will impact the decrease in the electric power potential of a micro-hydro system. The total length of the penstock  induces the variation of the   which affects the changes in the electrical power of the micro-hydro system. The shorter  will increase the electric power potential of a micro-hydro system. With a high flow velocity of water in the penstock (  m/s), the electric power increases linearly with increasing the diameter value of the penstock. The analysis results show that the penstock dimensions can affect the changes in the electric power of the micro-hydro system. In addition, the work presented in this article has shown that the CFD approach can be used as a low-cost initial step in building an actual micro-hydro system 
Machine Learning Models Based on Random Forest Feature Selection and Bayesian Optimization for Predicting Daily Global Solar Radiation Chaibi, Mohamed; Benghoulam, El Mahjoub; Tarik, Lhoussaine; Berrada, Mohamed; El Hmaidi, Abdellah
International Journal of Renewable Energy Development Vol 11, No 1 (2022): February 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.41451

Abstract

Prediction of daily global solar radiation  with simple and highly accurate models would be beneficial for solar energy conversion systems. In this paper, we proposed a hybrid machine learning methodology integrating two feature selection methods and a Bayesian optimization algorithm to predict H in the city of Fez, Morocco. First, we identified the most significant predictors using two Random Forest methods of feature importance: Mean Decrease in Impurity (MDI) and Mean Decrease in Accuracy (MDA). Then, based on the feature selection results, ten models were developed and compared: (1) five standalone machine learning (ML) models including Classification and Regression Trees (CART), Random Forests (RF), Bagged Trees Regression (BTR), Support Vector Regression (SVR), and Multi-Layer Perceptron (MLP); and (2) the same models tuned by the Bayesian optimization (BO) algorithm: CART-BO, RF-BO, BTR-BO, SVR-BO, and MLP-BO. Both MDI and MDA techniques revealed that extraterrestrial solar radiation and sunshine duration fraction were the most influential features. The BO approach improved the predictive accuracy of MLP, CART, SVR, and BTR models and prevented the CART model from overfitting. The best improvements were obtained using the MLP model, where RMSE and MAE were reduced by 17.6% and 17.2%, respectively. Among the studied models, the SVR-BO algorithm provided the best trade-off between prediction accuracy (RMSE=0.4473kWh/m²/day, MAE=0.3381kWh/m²/day, and R²=0.9465), stability (with a 0.0033kWh/m²/day increase in RMSE), and computational cost.
Catalytic Co-Pyrolysis of Palm Oil Empty Fruit Bunch and Coal into Liquid Oil Sunarno, Sunarno; Sari, Ronna Puspita; Frimacia, Tifanny; Yenti, Silvia Reni; Utama, Panca Setia; Saputra, Edy
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.42193

Abstract

The decline in fossil fuel sources has prompted research into finding renewable fuels. One of environmentally friendly energy sources with high efficiency is by producing liquid oil from palm oil empty fruit bunch (EFB) and coal. Pre-treatment of empty fruit bunches using NaOH and various concentrations of H2O2, various ratios of EFB/coal, the ratio of CaO catalyst, chemical and physical characteristics were studied to produce the better liquid oil yield. The H2O2 concentrations are 0%, 1%, 2%, and 3%. The ratios of EFB/coal (R) are 0/100, 25/75, 50/50, and 75/25. The ratios of catalyst CaO/raw material are 0%, 3%, 6%, and 9%. It ran at 400 °C with 100 mL/min nitrogen gas flowing during one hour. The results showed that adding sodium hydroxide and hydrogen peroxide in the EFB pre-treatment increased the liquid oil yield. With an increase in the EFB/coal ratio, the liquid oil yield increased. Co-pyrolysis treated EFB and Coal with a ratio of 75:25 produced 32% liquid oil yield, but the liquid oil yield decreased to 19% with the addition of 9% CaO catalyst. However, the addition of CaO catalyst reduces the acidity and increases the calorific value of the liquid oil.
Enhanced Geothermal Systems – Promises and Challenges Sircar, Anirbid; Solanki, Krishna; Bist, Namrata; Yadav, Kriti
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.42545

Abstract

Geothermal energy plays a very important role in the energy basket of the world. However, understanding the geothermal hotspots and exploiting the same from deep reservoirs, by using advanced drilling technologies, is a key challenge. This study focuses on reservoirs at a depth greater than 3 km and temperatures more than 150°C. These resources are qualified as Enhanced Geothermal System (EGS). Artificially induced technologies are employed to enhance the reservoir permeability and fluid saturation. The present study concentrates on EGS resources, their types, technologies employed to extract energy and their applications in improving power generation. Studies on fracture stimulation using hydraulic fracturing and hydro shearing are also evaluated. The associated micro-seismic events and control measures for the same are discussed in this study. Various simulators for reservoir characterization and description are also analyzed and presented. Controlled fluid injection and super critical CO2 as heat transmission fluid are described for the benefit of the readers. The advantages of using CO2 over water and its role in reducing the carbon footprint are brought out in this paper for further studies.
Synthesis and Characterization of Hydrochar and Bio-oil from Hydrothermal Carbonization of Sargassum sp. using Choline Chloride (ChCl) Catalyst Rustamaji, Heri; Prakoso, Tirto; Rizkiana, Jenny; Devianto, Hary; Widiatmoko, Pramujo; Guan, Guoqing
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.42595

Abstract

The purpose of this study is to alter the biomass of Sargassum sp. into elective fills and high valuable biomaterials in a hydrothermal process at 200oC for 90 minutes, using ZnCl2 and CaCl2 activating agents, withChClas a catalyst. This method generatedthree primaryoutputs: hydrochar, bio-oil, and gasproducts. ChCl to water ratio varies from 1:3, 1:1, and 3:1. The hydrochar yield improved when the catalyst ratio was increased, but the bio-oil and gas yield declined. The highest hydrochar yields were 76.95, 63.25, and 44.16 percent in ZnCl2, CaCl2, and no activating agent samples, respectively.The porosity analysis observed mesopore structures with the most pore diameters between 3.9-5.2 nm with a surface area between 44.71-55.2. The attribute of interaction between activator and catalyst plays a role in pore formation. The hydrochar products with CaCl2 showed the best thermal stability. From the whole experiment, the optimum hydrochar yield (76.95%), optimum surface area (55.42 m2 g-1), and the increase in carbon content from 21.11 to 37.8% were achieved at the ratio of ChCl to water was three, and the activating agent of ZnCl2. The predominant bio-oil components were hexadecane, hexadecanoic, and 9-octadecenoic acids, with a composition of 51.65, 21.44, and 9.87%, respectively the remaining contained aromatic alkanes and other fatty acids. The findings of this study reported that adding activating agents and catalysts improve hydrochar yield and characteristics of hydrochar and bio-oil products, suggesting the potential of hydrochar as a solid fuel or biomaterial and bio-oil as liquid biofuel
The Influence of Temperature and Irradiance on Performance of the photovoltaic panel in the Middle of Iraq Al-Ghezi, Moafaq Kaseim; Ahmed, Roshen Tariq; Chaichan, Miqdam Tariq
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.43713

Abstract

The photovoltaic (PV) panels are expected to be the most important systems to meet global energy demand by converting solar energy into electricity. The main obstacle to the widespread deployment of the PV systems its the limited efficiency, which are greatly affected by the solar radiation and the operating temperature. The full knowledge of the performance, efficiency and output power of photovoltaic modules and the extent of their change with the fluctuations of solar radiation and temperature is necessary to determine the optimal size of the system and avoid the financial risks of the project. This paper investigated numaricaly and experimentaly the influence of operating temperature and solar radiation on the output power and efficiency of polycrystalline PV panels in Baghdad-Iraq. The PVsyst software was used to simulate a model implementing simulation results presented the impact of variations temperature and solar radiation in the curves of I-V, P-V and efficiency. In order to verify the reliability of the simulated results with experimental ones, several measuring devices have been used to conduct field experiments in the outdoor conditions. It were used to determine the characteristics and performance of a 120W polycrystalline PV panel for different ranges of solar radiation and operating temperature. The simulation results showed that the current, voltage, output power and efficiency increased with increasing solar radiation, while they decreased with increasing temperature except the current that was increased. The experimental and simulated results were identical in terms of the effect of temperature and solar radiation on the current, voltage, output power and efficiency of the PV panel. The experimental tests showed that when the temperature is increased by 1°C, the current was increased by about 0.068%, the voltage decreased by 0.34%, the output power decreased by 0.489% and the efficiency decreased about 0.586%.  The experimental results displayed that the parameters of the PV panel under real operating conditions behave differently than in the standard test conditions (STC), as they are strongly affected by weather fluctuations in terms of temperature and solar radiation
Bioconversion of Industrial Cassava Solid Waste (Onggok) to Bioethanol Using a Saccharification and Fermentation process Soeprijanto, Soeprijanto; Qomariyah, Lailatul; Hamzah, Afan; Altway, Saidah
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.41332

Abstract

Cassava solid waste (Onggok) is a by-product of the starch industry containing a lot of fiber, especially cellulose and hemicellulose. It has the potential to be converted to bioethanol. This work aimed to evaluate the effect of feedstocks ratio for the optimal bioethanol production via enzymatic and acidic hydrolysis process in a batch fermentation process. The effect of alpha-amylase and glucoamylase activities was studied. The sulfuric acid concentrations in the hydrolysis process in converting cassava into reducing sugar were also investigated. The reducing sugar was then fermented to produce ethanol. Enzymatic and chemical hydrolysis was carried out with the ratio of onggok(g)/water(L), 50/1, 75/1, and 100/1 (w/v). In the enzymatic hydrolysis, 22.5, 45, and 67.5 KNU (Kilo Novo alpha-amylase Unit) for liquefaction; and 65, 130, and 195 GAU (Glucoamylase Unit) for saccharification, respectively of enzymes were applied. The liquefaction was carried out at 90-100⁰C for 2 hours. The saccharification was executed at 65 ⁰C for 4 hours. Meanwhile, the acidic hydrolysis operating condition was at 90-100 ⁰C for 3 hours. The fermentation was performed at pH 4.5 for 3 days. Fourier Transform Infra-Red (FTIR) analysis was conducted to evaluate the hydrolysis process. The highest ethanol was yielded in the fermentation at 8.89% with the ratio of onggok to water 100:1, 67.5 KNU of alpha-amylase, and 195 GAU of glucoamylase. Ethanol was further purified utilizing fractional distillation. The final ethanol concentration was at 93-94%.
Investigating the Environmental and the Energy Saving Behavior among School Principals through Classification Algorithms Ntanos, Stamatios; Kyriakopoulos, Grigorios L.; Anagnostopoulos, Theodoros; Xanthopoulos, Theodoros; Kytagias, Christos; Drosos, Dimitrios
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.43007

Abstract

Buildings are a significant energy consumption point since they account for 40% of the total energy demand and around 1/3 of greenhouse gas emissions. Energy-saving measures applied in the residential sector have led to a reduction in energy consumption during the last decade. On the contrary, such measures have not been widely applied in school buildings, although education is the second-largest energy consumer in the service sector. This paper aims to assess school principals' perceptions concerning energy saving and the environment since they are responsible for promoting energy-saving measures and investments and inspiring students and school personnel towards environmentally friendly behavior. Using survey data from Greek schools, we applied predictive classification models to locate the most critical variables that drive principals' perceptions of energy upgrading and energy-saving actions at school. Results revealed that the positive environmental perceptions of principals, the level of knowledge on Renewable Energy Sources (RES) and the active energy-saving behavior are related to energy-saving actions and energy upgrading in school environment. Furthermore, the creation of more RES oriented courses is related to positive energy-saving behavior and actions. Thus, emphasis should be put on educating and informing the school principals concerning RES technologies and energy-saving options since they are critical players in applying energy-saving measures in school buildings
Laminar Flame Characteristics of 2,5-Dimethylfuran (DMF) Biofuel: A Comparative Review with Ethanol and Gasoline Hoang, Long Vuong; Nguyen, Danh Chan; Truong, Thanh Hai; Le, Huu Cuong; Nguyen, Minh Nhat
International Journal of Renewable Energy Development Vol 11, No 1 (2022): February 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.42611

Abstract

Since the early years of the 21st century, the whole world has faced two very urgent problems: the depletion of fossil energy sources and climate change due to environmental pollution. Among the solutions sought, 2,5-Dimethylfuran (DMF) emerged as a promising solution. DMF is a 2nd generation biofuel capable of mass production from biomass. There have been many studies confirming that DMF is a potential alternative fuel for traditional fuels (gasoline and diesel) in internal combustion engines, contributing to solving the problem of energy security and environmental pollution. However, in order to apply DMF in practice, more comprehensive studies are needed. Not out of the above trend, this paper analyzes and discusses in detail the characteristics of DMF's combustible laminar flame and its instability under different initial conditions. The evaluation results show that the flame characteristics of DMF are similar to those of gasoline, although the burning rate of DMF is much higher than that of gasoline. This shows that DMF can become a potential alternative fuel in internal combustion engines.

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