International Journal of Renewable Energy Development
ISSN / EISSN : 2252-4940 / 2252-4940
Published by: Diponegoro University (10.14710)
Total articles ≅ 360
Latest articles in this journal
Published: 30 September 2021
International Journal of Renewable Energy Development, Volume 11, pp 83-94; https://doi.org/10.14710/ijred.2022.39295
. In this study, a robust optimisation method (ROM) is proposed with aim to achieve optimal scheduling of virtual power plants (VPPs) in the day-ahead electricity markets where electricity prices are highly uncertain. Our VPP is a collection of various distributed energy resources (DERs), flexible loads, and energy storage systems that are coordinated and operated as a single entity. In this study, an offer and bid-based energy trading mechanism is proposed where participating members in the VPP setting can sell or buy to/from the day-ahead electricity market to maximise social welfare (SW). SW is defined as the maximisation of end-users benefits and minimisation of energy costs. The optimisation problem is solved as a mixed-integer linear programming model taking the informed decisions at various levels of uncertainty of the market prices. The benefits of the proposed approach are consistency in solution accuracy and traceability due to less computational burden and this would be beneficial for the VPP operators. The robustness of the proposed mathematical model and method is confirmed in a case study approach using a distribution system with 18-buses. Simulation results illustrate that in the highest robustness scenario, profit is reduced marginally, however, the VPP showed robustness towards the day-ahead market (DAM) price uncertainty
Published: 1 September 2021
International Journal of Renewable Energy Development, Volume 11, pp 71-81; https://doi.org/10.14710/ijred.2022.38493
. In this study, data of the monthly average of daily global solar radiation falling on a horizontal surface, relative humidity, maximum temperature, and duration of sunshine for the city of Baghdad were collected through two sources. First, from the Iraqi Meteorological Authority (IMA) for a period extending from 1961 to 2016. The second is from NASA, for the period from 1984 to 2004. Then, four linear regression models, two single and two polynomials were formulated to calculate the values of the monthly average of daily global horizontal solar radiation (GHSR) incidents. The models calculated the monthly average of daily extraterrestrial radiation and day length, using some data provided by NASA and the IMA. To ensure the validity of the used models, a statistical test was performed for the performance of the proposed models, using the indicators mean bias Error (MBE), root mean square error (RMSE) as well as mean percentage error (MPE). The validation shows the relationship between the measured and computed values (through the analysis of the results), where a great convergence was found between the measured and calculated values. This means that the proposed models can be adapted to predict global solar radiation. The highest values of measured solar radiation were during the month of June, which were 28.555 and 27.280 MJ/m2/day from the IMA and NASA, respectively. The same applies to the radiation calculated using the four empirical models. The month of June was the highest in terms of solar radiation values. The radiation values were 28.947, 26.315, 29.699, and 26.716 MJ/m2/day for the first, second, third, and fourth models, respectively. The lowest values of measured and calculated radiation were during the month of December. Always, radiation measured by the IMA was greater than those of NASA, as well as the values of radiation calculated in the two IMA-based models were greater than the other two NSA-based models. In the absence of a method for measuring the diffuse and direct (beam) solar radiations, as well as the lack of such values by meteorological authorities, and its paramount importance, they were reported to mathematically calculate them in this study. The values of statistical indicators RMSE; MJ/m2/day, MBE; MJ/m2/day and MPE% were (0.4769, 0.0164, 0.2207), (0.8641, 0.1773, -0.9680), (0.6420, 0.3996, -1.1487), (0.9604, 0.218, -1.0225) for the first, second, third and fourth models, respectively. According to the results of the statistical test, it can be indicated that the single linear regression model, based on the IMA’s data (model No.1), is the most accurate to calculate global solar radiation for Baghdad City.
Published: 28 August 2021
International Journal of Renewable Energy Development, Volume 11, pp 63-69; https://doi.org/10.14710/ijred.2022.37768
The environments have created an abundance of residual plants from all life sectors, which is not optimal for bioethanol. Therefore, this research developed microbial technology that yielded sugar and fermentation testing. The research aimed to discover the delignification process and compare the consuming sugar by Saccharomyces cerevisiae between the chemical saccharification and accelerated bio-agent of fungal consortium in the engineered media. The innovation of the bioethanol process was conducted using raw materials from biomass. Based on this study, some preliminary hypotheses were made: (i) arranging fungal substrate which consists of residual sugar, molasses, and enriched residual papaya fruits could provide distinguishable growth of cell mass; (ii) the substrate concentration of 2.5% and 7.5% in the growth medium using enriched residual papaya fruits, respectively, as a medium, could be distinguished using delignification. A benchmark was used to compare the chemical and bio-agent saccharification. The consortium that grew and produced cell mass by times factor in molasses has fulfilled the element needed compared to the natural organic substances from the papaya fruit. The higher concentration of delignification material substrate yielded higher growth-saccharification and the average of 10.45 ± 0.21 % Brix was obtained by the fungal consortium in the broth medium, although the acceleration growth is insignificant. Nonetheless, Saccharomyces cerevisiae had successfully fermented saccharification yield sugar from the delignification of plants residual
Published: 1 August 2021
International Journal of Renewable Energy Development, Volume 10, pp 635-651; https://doi.org/10.14710/ijred.0.35558
In this paper, a multi-objective hydro-thermal-wind-solar power scheduling problem is established and optimized for the Kanyakumari (Tamil Nadu, India) for the 18th of September of 2020. Four contrary constraints are contemplated for this case study (i) fuel cost and employing cost of wind and solar power system, (ii) NOx emission, (iii) SO2 emission, and (iv) CO2 emission. An advanced hybrid simplex method named as-the -constrained simplex method (ACSM) is deployed to solve the offered problem. To formulate this technique three amendments in the usual simplex method (SM) are adopted (i) -level differentiation, (ii) mutations of the worst point, and (iii) the incorporation of multi-simplexes. The fidelity of the projected practice is trailed upon two test systems. The first test system is hinged upon twenty-four-hour power scheduling of a pure thermal power system. The values of total fuel cost and emissions (NOx, SO2, CO2) are attained as 346117.20 Rs, 59325.23 kg, 207672.70 kg, and 561369.20 kg, respectively. In the second test system, two thermal generators are reintegrated with renewable energy resources (RER) based power systems (hydro, wind, and solar system) for the same power demands. The hydro, wind, and solar data are probed with the Glimn-Kirchmayer model, Weibull Distribution Density Factor, and Normal Distribution model, respectively. For this real-time hydro-thermal-wind-solar power scheduling problem the values of fuel cost and emissions (Nox, SO2, CO2) are shortened to 119589.00 Rs, 24262.24 kg, 71753.80 kg, and 196748.20 kg, respectively for the specified interval. The outturns using ACSM are contrasted with the SM and evolutionary method (EM). The values of the operating cost of solar system, wind system, total system transmission losses, and computational time of test system-2 with ACSM, SM, and EM are evaluated as 620497.40 Rs, 1398340.00 Rs, 476.6948 MW & 15.6 seconds; 620559.45 Rs, 1398479.80 Rs, 476.7425 MW & 16.8 seconds; and 621117.68 Rs, 1399737.80 Rs, 477.1715 MW and 17.3 seconds, respectively. The solutions portray the sovereignty of ACSM over the other two methods in the entire process.
Published: 14 April 2021
International Journal of Renewable Energy Development, Volume 10, pp 769-778; https://doi.org/10.14710/ijred.2021.37822
This paper examines the relationship between energy consumption, economic growth, and environmental degradation in Indonesia in 1965-2018 with the inclusion of gross capital formation and trade openness as relevant factors. The autoregressive distributed lag model to cointegration, fully modified ordinary least squares, dynamic ordinary least squares, and canonical cointegrating regression approach applied to estimate this relationship. The result of cointegration confirms the existence of a cointegration relationship between energy consumption, economic growth, gross fixed capital formation, trade openness, and environmental degradation. The empirical result, in the long run, indicates that energy consumption, economic growth, and trade openness have a positive relationship with environmental degradation. However, the gross fixed capital formation was found to be negatively associated with environmental degradation. This implying that gross fixed capital formation plays a pivotal role to reduce environmental degradation in Indonesia. The error correction model coefficient indicates that the deviation of CO2 emissions from its long run equilibrium will be adjusted by 0.53% through the short run channel per annual. The findings of this paper propose implementing an energy policy that focuses on energy from environmentally friendly sources. Reverse the effect of openness to the international markets to improve and facilitate access to advanced and environmentally friendly technologies to mitigate environmental degradation and improve environmental quality.
Published: 14 April 2021
International Journal of Renewable Energy Development, Volume 10, pp 731-736; https://doi.org/10.14710/ijred.2021.36277
It is crucial to examine the dependence of photoelectric parameters of solar cells on the light incidence angle. In the present study, two solar cell models have been developed using the Sentaurus Technology Computer-Aided Design software package. The light spectrum AM1.5 has been directed on the frontal surface of solar cells at different angles. It has been found that the angular coefficient of the photoelectric parameters of a solar cell with nanoparticles included, is two times more than that of a simple solar cell. Besides, it has been found that the efficiency of platinum nanoparticles induced solar cells is 2.15 times greater than simple solar cell efficiency. When the light incidence angle has been varied from 0 to 60 degrees, the short-circuit current has changed by 11% for simple solar cells and by 10% for solar cells with nanoparticles. Further, it has been observed that the variation of power for simple solar cells is 12.5%, while it is 10.5% for solar cells with nanoparticles. In addition, the short-circuit current of solar cells with nanoparticles has been found to be linear within a light incidence angle ranging from 0 to 60 degrees.
Published: 14 April 2021
International Journal of Renewable Energy Development, Volume 10, pp 755-767; https://doi.org/10.14710/ijred.2021.34927
In many developing countries,the use of conventional power plants to generate electricity is not meeting the increasing demands. Therefore, it has become important to find sustainable alternatives. In the present study, a solar hybrid combined cycle power plant consisting of a solar thermal plant, large-scale gas and steam turbines, and a magnetohydrodynamic generator has been investigated under oxy-fuel combustion. The performance analysis of this system under fuel pressure rate varying from 10 to 25 bar was conducted using Cycle Tempo software. The analysis of the gas and steam combined cycle shows that the net powers and the net efficiencies obtained ranged from 98 MWe to 134 MWe and 30.5% to 40%, respectively. In addition, the integration of the magnetohydrodynamic generator to the combined cycle led to an increase in the overall power from 169 MWe to 205 MWe. Moreover, it is seen that the fuel mass rate (2.81 kg/s) obtained in the gas turbine system under oxy-fuel combustion is significantly reduced when compared to conventional systems. The incorporation of solar energy and oxy-fuel combustion in the gas turbine system has increased the combustor inlet and outlet temperature and reduced the fuel consumption. From these observations, the solar hybrid system proposed in this study does not only generates electric power but also reduce the turbine exhaust fumes and CO2 emissions, which is a key factor in minimizing environment pollution.
Published: 11 April 2021
International Journal of Renewable Energy Development, Volume 10, pp 653-666; https://doi.org/10.14710/ijred.2021.37135
Kaltim presumably experiences an energy paradox, where the energy system is unreliable and unsustainable, despite energy-rich. This study presumes that the paradox is caused by the ‘ill-advised energy policy’ shown by ‘energy-area incompatibility’ that is exacerbated by the ‘energy-rich syndrome’ (a mindset of feeling secure due to energy-abundance leading to a wasteful behavior). This study investigates the indication of the syndrome in Kaltim energy policy by first investigating ‘the incompatibility’ and its impacts by examining Kaltim’s geographical characteristics, energy potential, population-distribution, electricity system, and infrastructure. Also, the impacts of retaining the syndrome through cost analyses. This study finds the incompatibility between energy-sources utilization and geographical characteristics, by conducting a descriptive method with data collection and analyses. Kaltim is forest-dominated with scattered-population, suitable with an off-grid system. However, the electricity development is mostly on-grid, fossil-based designed, explaining the difficulties of electrifying the entire Kaltim, although electricity is surplus. While off-grid should be applied to NRE, the massive use of diesel-gen-sets shows wasteful behavior. By conducting a linear-regression method, this study finds that Kaltim’s electricity consumption (indicating the infrastructure sufficiency) is lower than it should be, given its incredible economic performance. The incompatibility causes infrastructure insufficiency. The cost analysis finds that the massively-used fuel oil is the most expensive. The subsidy would be around 0.003%-0.275% of Kaltim GDRP or 17 billion-1.55 trillion IDR. As the new Capital location, NRE is a must for Kaltim. To conclude, NRE utilization is very low, although its potential is huge, and Kaltim’s forested characteristics suit it. NRE only covers 3% of Kaltim’s electricity, while the potential (hydro alone) is more than 6,900MW. The incompatibility causes an unreliable electricity system, although electricity is surplus. Following Kaltim’s geographical characteristics, NRE should be optimized. This study intends to aware the policy-makers of the syndrome, thereby develop a ‘proper energy policy’.
Published: 1 April 2021
International Journal of Renewable Energy Development, Volume 10, pp 653-662; https://doi.org/10.14710/ijred.2021.33834
The disposal of industrial sewage sludge is one of the most serious environmental problems in Thailand. Moreover, the disposal expense is considered as the production cost to the manufacturer. Therefore, the concept of waste-to-energy technology (WTE) is applied to solve this problem. This study aimed to study the effect of sewage sludge and rice straw proportions on the properties of co-pellets. Here, the production of co-pelleted sewage sludge from the canned food industry, combined with biomass (rice straw), was performed using a lab-scale pelletization machine. The pellets consisted of sewage sludge (SS) and rice straw (RS) with sewage sludge ratios of RS100:SS0, RS50:SS50, RS35:SS65, RS25:SS75, and RS0:SS100. The co-pellets produced were characterized for physicochemical properties and calorific heating values. In addition, the benefit to cost ratio (B/C), internal rate of return (IRR), and payback period (PB) from the utilization of co-pellets were studied. The results suggest that the proportion of sewage sludge affects the properties of the co-pellets. The optimum sewage sludge to rice straw ratio at RS0:SS100 is considered to have good fuel combustion properties. It is suitable for the production of co-pellets because of its high volatility and low ash slagging content
Published: 13 February 2021
International Journal of Renewable Energy Development, Volume 10, pp 563-571; https://doi.org/10.14710/ijred.2021.33845
With the wide acceptance of modeling a PV cell by a single diode, a series and parallel resistors; many researchers have discussed different mathematical forms and iterative techniques to extract the values of these model elements depending on the key parameters provided by the manufacturer datasheet. This paper avoids iterative techniques and obtains the values of the five parameters of the one diode model by developing closed form expressions. The maximum error produced by this technique is 10% when compared to the exact values of the one diode model circuit built by Spice. The 10% maximum error has occurred during the estimation of the reverse saturation current (Io) of the diode, nevertheless, it should be mentioned that even for this same parameter the model outperforms many iterative dependent works. Furthermore, this paper discusses the effect of temperature on the operation performance of PV cells. In particular, the temperature effect on the open circuit voltage, the short circuit current, the fill factor, the reverse saturation current, and the conversion efficiency was modeled and evaluated for different brand technologies