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Abstract: There has been considerable interest focused on the investment for the production of oilseed crops for biodiesel. The advance research is needed to provide knowledge needed for the feasible way of adaptation of oilseed crops for biodiesel. Among the various oilseed crops produced, sunflower is a prominent summer crop that can be used to produce on-farm biodiesel for energy security. The objective of this paper is to estimate the overall economic benefits of biodiesel production from sunflower under small scale settings. The economic viability on production of biodiesel and its market opportunity to the farmers were investigated at its 3 different production stages namely; seed, oil and seed meal, and biodiesel production. The study was based on three different on-farm biodiesel extraction scenarios. For example, the seed press and biodiesel extractor can be operated at three different rates (low, medium and high). Feedstock production, capital investment for biodiesel units and operations costs were considered for the analysis. To calculate cost and revenue in annual equivalent terms, the present values of all costs and revenues over the useful life was transformed into an equivalent annuity. Analysis shows that biodiesel production from sunflower production could generate positive net returns under various scenarios. The analysis per volume basis showed that the production cost of biodiesel from sunflower oil to producer was between $2.00 to $3.21/gal when revenue from seed meal was accounted. The estimated break-even price of sunflower seed range from $0.18 to 0.26/kg depending upon sunflower yield. The findings of this research further improve the understanding of growing sunflower as an oilseed crops and on-farm processing of oil for local biodiesel production that could play vital role in improving farm income as well as sustainable and independent energy for small farmers. Keywords: Biodiesel, Seed meal, Seed press, Small farms, Summer oilseed crops, Sunflower.Download Full Article |
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Abstract: The main objective of this work is to conduct a feasibility study of utilizing small autonomous water desalination units powered by photovoltaic modules as a green renewable energy resource to be employed in different isolated zones as a source of drinking water for some scattered societies where the installation of huge desalination stations are discarded owing to the unavailability of electric grid in remote areas. Yanbu City is chosen as a case study where the Renewable Energy Center exists and equipped with all sensors to assess the availability of solar energy all over the year. The study included two types of available water: the first type is brackish well water and the second type is seawater of coastal regions. In the case of well water, two versions of desalination units are involved in the study: the first version is based on day operation only. While the second version takes into consideration the night operation, which requires energy storage system as batteries to provide the necessary electric power at night. According to the feasibility study results, it is found that utilization of small autonomous desalinations unit is applicable and economically accepted in the case of brackish well water. However, in the case of seawater the capital costs are extremely high and the cost of desalinated water will not be economically feasible unless governmental subsidies are provided. In addition, the study indicated that, for the same water production, the utilization of energy storage version (day-night) adds additional capital cost for batteries, and extra running cost for their replacement, which makes the unit price not only incompetent with day-only unit but also with conventional units powered by diesel generator (fossil fuel) owing to the low prices of fuel in the kingdom. However, the cost analysis shows that the price of the produced water per cubic meter of day-night unit is similar to that produced from the day-only unit provided that the day-night unit operates theoretically for a longer period of 50 %. Keywords: Renewable energy, solar energy, water desalination, reverse osmosis.Download Full Article |
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Abstract: Lignin depolymerisation has recently a great deal of attention from scientists and companies worldwide due to the extensive possibilities of this recalcitrant material for the production of chemicals, fuels and materials. The natural complexity and stability of lignin bonds makes lignin depolymerization a highly challenging task. Several efforts have been directed towards a more profound understanding of the structure and composition of lignin in order to devise pathways and selectively cleave bridging bonds to break down the biopolymer into useful compounds. The present contribution aims to provide a series of key points in the field of lignin depolymerisation to provide an overview to the field for starting researchers. Keywords: Lignin, depolymerisation, heterogeneous catalysis, chemicals, fuels, materials.Download Full Article |
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Abstract: In this study, an interval two-stage integer programming model is formulated for planning electric-power systems and managing carbon dioxide (CO2) emissions under uncertainty. The developed model can reflect dynamic, interactive, and uncertain characteristics of regional energy systems. Besides, the model can be used for answering questions related to types, times, demands and mitigations of energy systems planning practices, with the objective of minimizing system cost over a long-time planning horizon. The developed model is also applied to a case study of planning CO2-emission mitigation for an electric-power system that involves fossil-fueled and renewable energy sources. Solutions can help generate electricity-generation schemes and capacity-expansion plans under different CO2-mitigation options and electricity-demand levels. Different CO2-emission management policies corresponding to different renewable energy development plans are analyzed. A high system cost will increase renewable energy supply and reduce CO2 emission, while a desire for a low cost will run into risks of a high energy deficiency and a high CO2 emission. Keywords: CO2 emission, electric-power systems, optimization, planning, renewable energy, uncertainty analysis.Download Full Article |
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Abstract: In this research work silicon based solar panels were used to investigate the impact of series and parallel shading on the photovoltaic performance of inorganic solar panels. The results showed that voltage, current and power of the solar panels were reduced upon shading the series and parallel cells. This decrement was seen to be larger for the series shading compared to that of the parallel shading. This was attributed to the adverse effect of the series resistance of the shaded cells, which is acted as a bottleneck in front of the passage of current. This was not very effective in the parallel shading because current is readily capable to pass through the illuminated parallel cells and neglect the pathway of parallel shaded cells. From the results, it was concluded that the lower performance of solar panels due to shading effect is because of the change in the internal resistance of the panels. This situation is possible to occur during daily life use of solar panels as a result of the shading by clouds, dusts or trees. Hence, considerable investigation towards solving this problem is of great importance. Keywords: Solar panel, partial shading, photovoltaics, I-V characteristic.Download Full Article |