International Journal of Renewable Energy Technology (14 papers in press)
Short term solar energy forecasting using GNN integrated Wavelet based approach
by Priyanka Chaudhary, Mohammad Rizwan
Abstract: The power generation from solar energy is gaining more attention because of advancement in the solar photovoltaic technology including enhanced efficiency of solar cells by incorporating the good materials. In the present scenario the bidding of power is done on 15 minutes basis by many distribution companies. Keeping in mind aforesaid, 15 minutes ahead short term solar energy forecasting has been done and presented. As the power from solar energy is fluctuating and nonlinear in nature, the results obtained from mathematical models are not found satisfactory. Therefore, an intelligent approach based on wavelet transform and generalized neural network (GNN) is developed and applied for the short term solar energy forecasting problem. The results obtained from the proposed model are evaluated on the basis of statistical indicators like root mean square error (RMSE) and mean absolute error (MAE). It is concluded that the performance of the proposed model is found better as compared to GNN model.
Keywords: Generalized neural network; wavelet transform; grid integrated solar PV systems; solar energy forecasting.
Empirical model for prediction of density and water resistance of corn cob briquettes
by Simeon Jekayinfa, Ralf Pecenka, Ifeolu Orisaleye
Abstract: Biomass obtained from agricultural wastes have a high potential for energy generation, particularly in developing countries. The poor properties of the agricultural biomass cause handling problems and limit the suitability as fuel in conventional grates. Densification of biomass into briquettes enhances its fuel properties. In this study, effects of pressure (9, 15 MPa), temperature (90, 120
Keywords: Biomass briquette; densification variable; corn cob; empirical model; density; water resistance.
Eucalyptus Biofuel Study as Alternative for Diesel Engine
by Bousbaa Hamza, Lyes Tarabet, Khatir Naima, Abdelkrim Liazid, Mohand Tazerout
Abstract: Biodiesel is a hopeful alternative to petroleum-based diesel fuels. Its expanded use in unmodified engines has been very successful. After a brief synthesis on vegetable biofuels as alternatives for compression ignition engines, this paper present a study of a biofuel from the eucalyptus tree leaves. This vegetable source is selected due to its strong availability in South and North of Africa, California, Latin America, Europe and all the Mediterranean countries. Eucalyptus trees are original to the Australian continent where they dominate more than 90% of the forests. In this study, the investigations are performed for a direct injection diesel engine, single cylinder and four-stroke with rated power of 5.4 kW. The effects of neat eucalyptus biofuel and its different blends with diesel fuel are examined at different loads. Comparative measures of brake thermal efficiency, volumetric efficiency, brake specific fuel consumption, exhaust gas temperature and pollutant species are presented and discussed. The impacts of neat eucalyptus biofuel are examined at twice loads (50% and 90% of full load).A numerical investigationsunder three dimensional Reynolds-averaged Navier Stokes approachhave been carried out for more investigations using the computational fluid dynamic code Converge. Sub-models are employed to describe respectively the in-cylinder turbulence and combustion processes. Results show that when the engine is supplied with neat eucalyptus fuel, the combustion characteristics are slightly changed compared to neat diesel fuel and the soot species are reduced. The numerical investigations have also permit to analyze the impact of injection timing on the soot and Oxides of Nitrogen emissions.
Keywords: Diesel engine; Biodiesel; Eucalyptus; Combustion modelling; Gaseous emissions; Engine numerical simulations.
Renewable Energy Investment Prospects in Turkeys Power Generation Sector
by Linet Ozdamar
Abstract: Turkeys power demand is mainly met by fossil fuel generation plants. In the last decade, Turkey has focused on hydro power development in order to reduce carbon emissions and her dependency on imported fuels. 25% of power demand is met by hydropower, however, in the long term, hydropower efficiency is expected to decrease due to desertification. Turkey has also recently embarked on wind power development; however, its potential is not so high on a national scale. At present, solar farm capacity is almost non-existent despite the fact that Turkey has a good insolation level. Here, we develop a model that considers various renewable resource options to meet long term demand while maximizing the net present value of the power generation sectors net returns. The results of this model indicate that the sector can be transformed into a sustainable one over the next two decades by directing the majority of new investments to solar power while also using the full potential of wind and hydro power. Renewable resource share in power supply can go up to 65% by the year 2040 if appropriate policies such as carbon tax is implemented while continuing to provide current renewable energy purchase incentives. The model also provides the annual and cumulative expenses of the Ministry of Energy and Natural Resources for different demand, purchase price, renewable resource share goals and different carbon tax implementation scenarios for subsidizing renewable resource investments.
Keywords: power generation; renewable resources; long term power supply plan; government subsidies and budget; carbon tax; renewable energy targets; climate impact on hydropower; long term power consumption scenarios; private sector financial planning; Net Present Value of power sector; mathematical model; Mixed Integer Programming;.
Contribution to The Reliability Study of Photovoltaic Systems Using Static and Dynamic Analysis Methods
by Ismahan Mahdi, Bouchra NADJI, Zineb SIMEU-ABAZI
Abstract: The access to clean energy became, more and more, large with the technological revolution in the industry, in particular, solar energy. Considering the competing manufacturing of the solar panels, it is interesting to guarantee: the reliability, the availability, as well as the durability of these panels. However, the study of reliability has not been received great attention from researchers. An estimation of lifetime and why not improve enhance it, is still possible. For that, it is necessary to distinguish the different failure modes, their causes and their effects on solar modules, in our case composed by Silicon, the most spread technology and the most used in the production of electricity. In this article, we will present a contribution to the reliability study of photovoltaic (PV) systems. First, the study will be focused on the static analysis of our PV system by using: SADT (Structured Analysis and Design Technique) and FAST (Function Analysis System Technique) methods, which make it possible to carry out a functional analysis of our system. In the second time, our study will be based on the dynamic analysis by using: the FMECA (Failure Mode, Effects, and Criticality Analysis), the FTA (Fault Tree Analysis) and finally the SPN (Stochastic Petri Nets) methods. These allow making a dysfunctional analysis of the system by introducing the time factor which is very important in our study.
Keywords: Solar energy; PV module; Reliability; Failure; Petri Nets; MTBF; Fault Tree.
Enhancing the Performance of a Building Integrated Compound Parabolic Photovoltaic Concentrator using a Hybrid Photovoltaic Cell
by Damasen Ikwaba Paul, Mervyn Smyth
Abstract: In this study, a hybrid photovoltaic (PV) cell consisting of high efficiency and low efficiency cells was designed and fabricated. For comparison, low efficiency single cell was also fabricated and both PV cells were evaluated within a CPC. The fabrication of a hybrid cell was based on the simulation analysis which identified the regions with high energy concentration and low energy concentration in the CPC. Results indicates that the overall experimental daily power output of a hybrid PV cell on a clear sunny day and partial cloud day is higher than that of low efficiency single PV cell by 12% in both cases. On the other hand, the overall theoretical daily power output of a hybrid PV cell on a clear sunny day, partial cloud day and overcast day is also higher than that of low efficiency single PV cell by 11%, 10% and 13%, respectively.
Keywords: Building integrated concentrating Photovoltaic; symmetric 2-dimensional compound parabolic concentrator; hybrid PV cell; low efficiency single PV cell; non-uniform illumination; experimental daily power output; theoretical daily power output; low-concentrating system.
Effect of some operational conditions on bioelectricity production in algal fuel cell
by Victoria Adenigba, Julius Oloke, Iyabo Omomowo, Collins Odjadjare, Oluwabusayo Oluyide, Seun Ogunsona
Abstract: Optimization of bioelectricity production from microalgae in double chamber algal fuel cell was investigated. Ten microalgae were isolated from pond and sea water. They were identified as follow: Nanochloropsis sp, Chlorella sorokiniana and Coelastrella sp.. Others include Chlorococcum sp, Neodesmus pupukensis, Chlorella vulgaris, Leptolyngbya boryana, Chlamydopodium starrii, Parachlorella sp. and Neochloris aquatica. The bioelectricity potential of these microalgae was determined in human urine as substrate. Three microalgae; C. vulgaris, C.sorokiniana and Parachlorella. sp with the best output were selected for optimization: pH, inoculum size, salt bridge concentration, oxidizing agent and number of salt bridge. At the end of the different experiments, C.vulgaris, C.sorokiniana and Parachlorella sp. had maximum output of (1.49 V;1.31 mA), (1.67 V; 1.4 mA) and (1.46 V; 1.25 mA) respectively. The optimum requirement for the 3 microalgae were similar: pH of 8-8.5, 10-15 ml of each algal as inoculum,1 M KCl based salt bridge, potassium permanganate as oxidizing agent and increase in the number of salt bridges favoured optimum performance by each microalgae.
Keywords: Algal fuel cell; Human urine; Microalgae; Optimization; Pond water; Sea water.
Testing and Simulation of a Solar PV / Battery Storage System with and without PWM Charge Control
by Wael Yassine, Kevin Anderson
Abstract: This paper presents an experimental and modelling study of an off-grid solar photovoltaic system using pulse width modulation (PWM) charge control and battery storage using Manganese Oxide as the cathode, Carbon Titanium Phosphate Composite as the anode, and Alkali-ion Saltwater as the Electrolyte battery cells. The paper presents the development and fabrication of a test apparatus, experimental data collection and numerical modelling and simulation of the system. The experimental data for charging and discharging the system is used to correlate the numerical simulation model output. Results for charging and discharging the system are subsequently used to develop transfer function models of the systems charging and discharging behavior.
Keywords: photovoltaic; batteries; charge controller; modeling; simulation; experimental.
Special Issue on: ECRES2018 Advances in Renewable Energy
Investigation of the efficiency of a solar dryer with thermal storage by rock salt and by pebble bed
by HICHAM EL FEROUALI, AHMED ZOUKIT, ISSAM SALHI, SAID DOUBABI, NAJI ABDENOURI
Abstract: Storage materials by salt rocks and pebbles were introduced in an indirect solar dryer. Experiments were carried out by using rock salt and pebbles (0.076m3) as thermal storage materials. To overcome the thermal behaviour with storage materials, the solar dryer was modelled by SolidWorks flow simulation. Rock layers were arranged as superimposed sphere beds. The maximum reached temperature during the sunny period and the duration of the thermal discharge phase are strongly affected by the location of rocks in the drying chamber. These storage media maintained consistent the drying chamber temperature in the absence of the solar radiation by four more hours. Experimental tests were performed on lemon with and without the storage medium. Finally, the insertion of storage medium could increase the dryer efficiency by about 13.83%. Pebbles seem to be more suitable for thermal storage not for their thermal capacity but especially for their density.
Keywords: CFD modelling; thermal storage; pebble bed; rock salt; dryer efficiency.
The effect on the efficiency of the photovoltaic panel used for the charging of mobile phones of the solar radiation in Elazig, Turkey
by Ahmet YILDIZ, Beşir DANDIL, Gülşah ÇAKMAK
Abstract: In this study, mobile phone charge analysis was performed with portable solar panel in changing irradiation conditions and the efficiency of photovoltaic panel was determined. In photovoltaic systems, it is necessary to take into account the actual environmental conditions in the installation site to accurately determine the system performance. In this context, the aim of this study is to determine the efficiency of portable photovoltaic panels used to charge mobile phones in real outdoor conditions and to contribute to the use of the system in maximum efficiency. The designed system was tested in Elazig/ TURKEY province under external atmospheric conditions. Experiments were done in different months and throughout days in 2017. Radiation and outdoor temperatures were measured during the experiments. As a result, it was seen that the actual meteorological values affect the efficiency of the photovoltaic panel and the panel efficiency ranged from 12% to 19% for the Elazig province.
Keywords: Battery charger; current; efficiency; Elazig; mobile phone; photovoltaic panel; power bank; solar radiation; voltage.
Improving Photovoltaic Panel Performance Using a Flipping Technique Analysis and feasibility study
by Ahmad El Mais, Mohamad Abou Akrouch, Mohamad Hawa, Farouk Hachem, Mohamad Ramadan, Mahmoud Khaled
Abstract: Scientists all over the world are striving to improve the efficiency of the photovoltaic panel by many different techniques to maintain its temperature in the range of PV operation. In this paper a new technique of cooling photovoltaic panels PVs is suggested and investigated theoretically based on experimental behaviour obtained for a single PV panel. This technique is based on a flipping method consisting of two PV panels A and B installed at the opposite direction of each other. Initially Panel A is active, after certain time when the temperature of panel A increases above a prescribed limit, the system rotates the panels to become panel B the active panel. This technique is based on previous experiment and studied at two different flipping temperatures (36
Keywords: Solar energy; PV panel; Flipping technique; Enhancement; Efficiency.
The impacts of the geographical location on the performance of PV system- Skikda in Algeria and Atbara in Sudan: case study
by Osman Abdeen, Mourad Mordjaoui, Salim Haddad
Abstract: The meteorological situation is different from one place to another, so this affects the production of the photovoltaic system. Therefore, it is very important to use a simulation tool for photovoltaic system to select all components so as to know the generating energy according to the geographical location and to choose the optimal operating for photovoltaic system. This paper study the impacts of geographical location on the output of energy from photovoltaic system (5 MW) particularly apply in Skikda and Atbara, to compare annual energy output in order to select the best site to connect with the grid. The comparison which has been , done using four methods for controlling the photovoltaic array (fixed tilt, seasonal tilt , tracking horizontal, tracking vertical). The network was designed in PVsyst program by using (latitude, longitude, elevation ,time Zone ) of Skikda and Atbara and then all components of photovoltaic system have been selected . The results of simulation show the total quantity of electrical annual energy produced by photovoltaic system in Atbara is greater than that which produced with same system in Skikda, about 18.66%, 16.49%, 18.60%, and 8.93% of the energy injected into grid in Skikda for fixed tilt, seasonal tilt, tracking horizontal and tracking vertical respectively.
Keywords: Photovoltaic (PV); PVsyst; geographical location; effective energy; annual energy.
Development of a 2-D Numerical Transient Model to study Geothermal Coaxial Borehole Field Heat Exchangers
by Mohamed Salah Saadi, Rabah Gomri
Abstract: Coupling ground source heat pump system (GSHPS) with borehole heat exchangers (BHE) represents the best tool to exploit shallow geothermal energy. In many previous studies, only a single or few factors that influence the sustainability of a GSHPS were investigated. In the present paper a numerical 2D transient model has been built and implanted in MATLAB, which is suitable to predict transient temperature distributions of the heat carrier fluid and the surrounding soil over the well depth for a borehole field and this is under thermal interferences; it has been compared against two analytical solutions and the numerical code COMSOL where the results has been found identical. This model accounts for axial effects, porosity, underground-water flow and phase change in the soil simultaneously. A coaxial borehole heat exchanger has been selected regarding to its better performances. The model parameters are based on local conditions of Constantine area - Algeria. The results show, for the thermal investigation in the surrounding ground, that porous grounds are more suitable for these systems, when porosity is 0% the thermal load decreases by 15.725% than the case where porosity is 45%; also, it has been found that after occurrence of phase change in the saturated sub-ground, effective thermal properties changes in a way to make the withdrawn thermal load decreases in a more intense manner, it reduces by 5.36% than the case where the process is not accounted for and this is during the last 843h (35 days) since the process start; the last part of the thermal investigations yields that the underground-water flow is favoured for the system performance. This study can be used as a tool for sizing a BHE field.
Keywords: Geothermal Energy; Axial Effects; Thermal Interferences; Phase Change; Porosity; Under Ground-Water Flow; Finite Volume Method.
Special Issue on: Sustainable Energy Technologies
STUDIES ON HYDROGEN FUELLED STATIONARY C. I. ENGINE OPERATED END-UTILITY SYSTEM
by Vinod Singh Yadav, Dilip Sharma, S.L. Soni
Abstract: The refineries turned in a better performance with their cumulative 181 million tones crude throughput, almost 7 per cent more than the previous fiscals achievement and a little over 2 percent of the planned target. The world is presently confronted with the twin crisis of fossil fuel depletion and environmental degradation. Combined residential and commercial energy demand is expected to increase in order to meet the expected increase in electricity demand as the worlds population shall grow and more people shall move to urban areas with access to electricity. The search for an alternative fuel, which promises a pleasant link with sustainable development, energy conservation, management, efficiency, and environmental safeguarding, has become highly noticeable in the present context. rnIn this investigation, fresh air with hydrogen enrichment was used as intake charge in a C. I. engine. Experiments were conducted on a 1-C, 4-S, air-cooled, stationary direct-injection diesel engine (Kirlosker TAF1) with maximum 1500 rpm and maximum 4.4 kW capacity coupled to an electrical generator. The injection timing (17
Keywords: Hydrogen-Enrichment; Injection timing; Flow rate of hydrogen; Performance.