Forthcoming and Online First Articles

International Journal of Renewable Energy Technology

International Journal of Renewable Energy Technology (IJRET)

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International Journal of Renewable Energy Technology (11 papers in press)

Regular Issues

  • Experimentation studies of microalgae biodiesel blends influence on variable compression ratio diesel engine performance and exhaust emission characteristics   Order a copy of this article
    by Bhojraj N. Kale, S.D. Patle, S.R. Kalambe 
    Abstract: Microalgae are found to be most competent and unswerving resource of biodiesel due to their attentional attributes like non-eatable, non-requirement of crop-land for their cultivation. This work was directed to investigate the capability of novel, often overlooked biodiesel from microalgae species, which can be utilised as a substitute fuel in place of traditional diesel. The experimental investigation of impact of biodiesel on performance along with exhaust emission characteristics of single cylinder diesel engine was researched. Various blends of microalgae biodiesel presented a reduction in torque and hence brake power resulting in average reduction of 7.14% in the BTE also 11.54% increase of BSFC as equated to petroleum diesel. With increase in blends ratio in diesel, there were considerable reductions in exhaust emission characteristics which are CO and HC. However, for all the algal biodiesel blends, NOx and CO2 increases but compatible and in acceptable range.
    Keywords: algal biodiesel; fuel properties; VCR compression ignition engine; performance characteristics; emission characteristics.
    DOI: 10.1504/IJRET.2022.10048728
  • Characterisation of Terminalia ivorensis bio-char produced using a fixed-bed tubular reactor   Order a copy of this article
    by Joseph Adewumi Oyebanji, Josiah P. Obinna, Olawumi Taiye Oyebanji 
    Abstract: Terminalia ivorensis (TI) bio-char was investigated within the temperature range of 400C to 700C. The bio-char yields were characterised using analytical method. Proximate analysis showed that volatile matter, ash content and fixed carbon are 19.55, 1.20, and 79.45% respectively. The ultimate analysis results showed the carbon, hydrogen, nitrogen, oxygen, and sulphur as 74.90, 13.33, 0.86, 10.85 and 0.06% respectively. The moisture content for TI is 8.04% with highest HHV (30.90 MJ/kg) while the HHV of bio-char from the analysis of the samples ranged from 29.35 MJ/kg to 30.92 MJ/kg. Bio-char SEM-EDX and FTIR results show visible structural porosity and shaky surface morphology with the presence of oxygen. This investigation shows that the pyrolysis products of wood sawdust have adequate fuel properties as alternative source of energy.
    Keywords: biomass; pyrolysis; characterisation; higher heating value; HHV; renewable.
    DOI: 10.1504/IJRET.2022.10049898
  • Optimisation of series and parallel combination of N-SPVT air collectors based on overall thermal energy and exergy   Order a copy of this article
    by G.N. Tiwari, Prashant Bhardwaj, Sujata Nayak, Arvind Tiwari 
    Abstract: It is established that solar collectors connected in series for a constant mass flow rate in forced mode provide variable higher operating temperatures. In this case, thermal energy can be stored in a separate insulated storage tank for later application preferably either in domestic or preheating of industrial requirements. However, some industries need constant outlet temperature due to its sensitive nature, particularly in solar drying/cotton industries. Hence in this paper, we have analysed a semi-transparent photo-voltaic integrated air collector refer as SPVT air collectors which are connected in the combination of series and parallel keeping collection outlet temperature constant. For a typical day in New Delhi, India, modelling of SPVT and numerical computations has been done using basic energy balance equations. The optimisation of design parameters has been done based on overall thermal energy and exergy. It has been found that overall thermal energy and exergy are independent of series and parallel combinations keeping collection temperature constant. The effect of constant collection temperature, number of SPVT air collectors, and packing factor has also been studied.
    Keywords: solar energy; photo-voltaic thermal; PVT; module; air collector and exergy.
    DOI: 10.1504/IJRET.2022.10051006
  • Energy management of gravity energy storage to boost solar energy invasion   Order a copy of this article
    by Stella Morris, Laya M. A. Al-Hilfi, Peer Fathima Abdul Kareem, Morris Ezra 
    Abstract: Due to the sporadic nature of renewable energy, RE, maintaining an energy balance becomes challenging for utilities. An increased energy storage capacity would help resolve these challenges. A cutting-edge new grid-scale energy storage technique being studied is gravity energy storage, GES. Even though the literature suggests that GES may be a good replacement for existing energy storage techniques, there isn’t much research on its potential to boost RE penetration. Therefore, an energy management algorithm is developed for a modified IEEE system to optimise the GES and compare its potential in increasing solar penetration with respect to battery energy storage. A modified particle swarm algorithm is used to minimise network losses. Results show that the solar penetration is increased by 7.26% for the selected data, but the performance of both GES and BES are similar except for how their energy statuses differ owing to variations in depths of discharge.
    Keywords: gravity energy storage; GES; battery energy storage; solar energy; energy management; optimum scheduling; modified particle swarm optimisation.
    DOI: 10.1504/IJRET.2022.10052275
  • Comparative analysis of various methods to enhance the bioethanol production   Order a copy of this article
    by Kumari Yogyta, Kaul Kanak, Sarin Lakshmi, Jain Sadhna, Pratyusha Vavilala 
    Abstract: Bioethanol is a green fuel that is it is produced from renewable biological materials such as plant biomass. Our study aims to find out the most efficient and eco-friendly method for producing bioethanol from the feedstock and considers several parameters, including the selection of feedstock, pre-treatment method, enzymatic hydrolysis, fermentation and fractionation step. It is concluded that lignocellulosic biomass is the best material. Agriculture waste such as duckweed and agro-industrial waste can also serve as a good lignocellulose-rich biomass substrate. Duckweed with its low lignin content, low doubling time, and cheap pre-treatment appears to be the most suitable choice for bioethanol production. Genetically modified microorganisms for the production of ethanol from a mixture of sugars and a single stage fermentation using fed-batch process would be preferable. A combination of the above-mentioned processes and materials should provide efficient and low-cost bioethanol production, which would be a significant competitor to fossil fuels.
    Keywords: bioethanol; biofuel; duckweed; nanoparticles; sustainable energy.
    DOI: 10.1504/IJRET.2022.10052512
  • Experimental study and comparison of integrated solar dryer with and without reversed absorber and reflector   Order a copy of this article
    by Vijay R. Khawale, Bhojraj N. Kale, Vilas G. Dhore 
    Abstract: The aim of this manuscript is to recommend a solar crop dryer with reversed absorber and reflector which collects the maximum possible solar emission. For experimentation, the model was made adjustable such that it can satisfy the required conditions. Two types of solar dryers are used: 1) solar dryer without reversed absorber and reflector; 2) solar dryer with reversed absorber and reflector. The average collector efficiency (ηc), drying efficiency (ηd) and the picking efficiency (ηp) of multi-pass SCD with reversed absorber and reflector (SD6) values were 34%, 49% and 64% respectively. Excel software was used to find the changes in moisture content with the time and constants by graphical method. These values show that SD6 is more effective than any other solar dryer. The experimental data is more suitable for Pages' model than other models. Pages' model gives the best results with the maximum value of R2 and the minimum value of MBE and RMSE. It has been found that SD6 is the most effective solar dryer and can be used to dry other agriculture food products also.
    Keywords: flat plate collector; solar crop dryer; reversed absorber; reflector; red chilli.
    DOI: 10.1504/IJRET.2022.10048427
  • Incorporating grid extension into the geospatial multi-criteria analysis of the suitability of multi-renewable energy projects   Order a copy of this article
    by Dave J. Pojadas, Michael Lochinvar S. Abundo 
    Abstract: Geographic information system-assisted multi-criteria analysis is the most popular approach in selecting the most suitable sites for renewable energy projects. The current practice in this approach often takes only one or two technologies at a time (mostly solar and wind), and grid extension has never been considered in the process. This paper presents a methodology for selecting sites for utility-scale renewable energy projects considering solar, wind, biomass, and hydro resources all at once. Splitting the study area according to proximity from the existing grid and extending the latter to relatively distant areas is proposed to account for the possibility that resource quality may outperform grid infrastructure investment. As a parallel research objective, the sensitivity of new (terrain ruggedness index and resource density) and traditional ranking criteria was investigated. The case study showed that a resource over 5 km away from the grid is a better project option when the grid is extended.
    Keywords: grid extension; geospatial; multi-criteria analysis; suitability analysis; renewable energy; wind energy; solar energy; biomass; hydropower.
    DOI: 10.1504/IJRET.2022.10048428
  • Techno-economic optimisation of a standalone solar PV battery energy storage system: a metaheuristic approach   Order a copy of this article
    by Kudzanayi Chiteka, Tendaishe Munetsiwa, Tatenda Kanyowa, Garikayi Victor Nyakujara, Emmanuel Ndala 
    Abstract: This study optimised the battery energy storage system of a standalone solar home system. The optimisation considered the futuristic price drops in battery energy storage systems due to future technological developments. Two battery technologies, i.e., the lithium ion battery type and the sealed maintenance free battery were analysed. This study modelled the life of a battery energy storage system against the depth of discharge and the cost of energy storage. It was revealed that optimising the battery energy storage system considering future price drop reduced the levelised cost of energy by at least 17% and in this study a levelised cost of energy of US$0.066 was obtained which is 8.33% less than the standard domestic tariff in Zimbabwe. This study recommended an optimal depth of discharge of respectively 73% and 45% for lithium ion batteries and sealed maintenance free batteries.
    Keywords: solar energy; battery energy storage system; BESS; optimisation; metaheuristic; solar home system; SHS; depth of discharge; DoD.
    DOI: 10.1504/IJRET.2022.10048345
  • Soil thermal saturation characteristics a limiting performance parameter of an Earth air heat exchanger - an experimental investigation   Order a copy of this article
    by Swati Donde, Ram Subhash Maurya 
    Abstract: In the continuous work of an Earth air heat exchanger (EAHE), the thermal saturation of the soil adversely affects its further workg. Hence, for its in-depth analysis, an actual EAHE is modelled as an equivalent cartridge heater and as a source of heat in the soil. Four soil samples were considered for the experimental investigation. The nature of heat propagation in all soil samples under continuous heating for six hours was recorded and studied. In terms of thermal saturation, the soil with the highest thermal conductivity (0.61W m-1 K-1) performed better than the soil with the lowest thermal conductivity (0.01W m-1 K-1). For all soil samples, the maximum heat-affected zone is up to 0.15 m from the heat source. The present work proposes an efficient method of easy investigation to characterise the site soil, which is cost-effective and less laborious compared to other available methods. This paper is really helpful for EAHE designers.
    Keywords: earth air heat exchanger; EAHE; thermal saturation; modelling; soil; geothermal; cooling/heating; experimental investigation.
    DOI: 10.1504/IJRET.2023.10051078
  • A multi-objective decision framework for the selection of feasible and viable hybrid renewable energy systems in energy-constrain communities   Order a copy of this article
    by Zwalnan Selfa Johnson, Yousif Abdalla Abakar, S. Anandan Shanmugam, Andy Chan 
    Abstract: Choosing the appropriate system configuration that meets the multi-objective of profit-making and environmental protection is always a critical decision for both entrepreneurs and the government. The choice is complicated primarily if several possible alternatives exist. In this paper, a decision framework was developed to select from four configurations, the configuration that best fits decision-makers' multi-objective of profit-making and environmental protection. It was found that, overall, the grid-connected PV-battery hybrid configuration, for now, offers the best fit to the desired profitability and CO2 mitigation effort with a similarity index of 96.10%. Whereas for now, the standalone PV-batt configuration is only about 29.93% close to this desired objective. It is inferred, therefore, that the complete exclusion of conventional energy from the concept of sustainable energy, for now, leads to an unequivocal increase in installation costs, preventing investments in green technology, particularly in developing countries.
    Keywords: hybrid energy system; techno-economic; multi-objective; CO2 emission.
    DOI: 10.1504/IJRET.2022.10049897

Special Issue on: Emerging Advances of Solar Thermal Applications for Sustainable Development

  • Thermal and exergy analysis of N-semi-transparent photovoltaic thermal air collectors connected in series/parallel   Order a copy of this article
    by G.N. Tiwari, Prashant Bhardwaj, Sujata Nayak, Arvind Tiwari, V.K. Dwivedi 
    Abstract: An attempt has been made to develop a thermal model of a semi-transparent photovoltaic thermal (SPVT) air collector connected in series and parallel for a given total number of PVT air collectors. It has been observed that the temperature of outlet fluid (air) increases with the increase of the number of SPVT air collectors connected in series along with the decrease in electrical efficiency of a solar cell of PV module. In order to maximise the thermal as well as electrical output, one has to analyse the combination of SPVT air collectors (N). It has been observed that: 1) all SPVT air collectors should be connected in series based on an overall thermal energy; 2) 3-SPVT and 4-SPVT air collectors should be connected in series and parallel combination respectively for maximum overall exergy for given 12-SPVT air collectors. Further, the effect of mass flow rate and packing factor has also been studied.
    Keywords: SPVT air collectors; overall energy; series and parallel connection; and solar energy.
    DOI: 10.1504/IJRET.2022.10051513