22 research outputs found
Self-Transforming Configuration Based on Atmospheric-Adaptive Materials for Solid Oxide Cells
Solid oxide cells (SOC) with a symmetrical configuration have been focused due to the practical benefits of such configurations, such as minimized compatibility issues, a simple fabrication process and reduced cost compared to SOCs with the asymmetrical configuration. However, the performance of SOCs using a single type of electrode material (symmetrical configuration) is lower than the performance of those using the dissimilar electrode materials (asymmetrical configuration). Therefore, to achieve a high-performance cell, we design a 'self-transforming cell' with the asymmetric configuration using only materials of the single type, one based on atmospheric adaptive materials. Atmospheric-adaptive perovskite Pr0.5Ba0.5Mn0.85Co0.15O3-delta (PBMCo) was used for the so-called self-transforming cell electrodes, which changed to layered perovskite and metal in the fuel atmosphere and retained its original structure in the air atmosphere. In fuel cell mods, the self-transforming cell shows excellent electrochemical performance of 1.10Wcm(-2) at 800 degrees C and good stability for 100 h without any catalyst. In electrolysis mode, the moderate current densities of -0.42A cm(-2) for 3 vol.% H2O and -0.62 A cm(-2) for 10 vol.% H2O, respectively, were observed at a cell voltage of 1.3V at 800 degrees C. In the reversible cycling test, the transforming cell maintains the constant voltages for 30 h at +/- 0.2A cm(-2) under 10 vol. % H2O
Wind power resource in the south-western region of Algeria
In this study, we present a statistical analysis of wind speeds at Tindouf in Algeria using Risoe National Laboratory's Wind Atlas Analysis and Application Program (WAsP). It requires information related to the sheltering obstacles, surface roughness changes and terrain height variations in order to calculate their effects on the wind. Wind data, consisting of hourly wind speed records over a 5-year period, 2002-2006, were obtained from SONELGAZ R&D Office; the average wind speed at a height of 17ĂÂ m above ground level was found to range from 7.19 to 7.95ĂÂ m/s. The Weibull distributions parameters (c and k) were found to vary between 8.0 and 8.9ĂÂ m/s and 2.54-3.23, respectively, with average power density ranging from 318 to 458ĂÂ W/m2. The dominant wind directions and the frequency distributions were also determined.Tindouf WAsP Weibull parameters Wind power resource
Assessing the wind energy potential projects in Algeria
A research program is under way in the SONELGAZ R&D Office with the aim of studying the potential of wind energy in Algeria. This paper presents an analysis of recently collected hourly wind data over a period of almost 5 years between 2002 and 2006, from four selected sites as well as preliminary evaluation of the wind energy potential. The results showed that Tindouf and DĂ©ly Brahim sites have higher wind energy potential with annual wind speed average of 5.8 and 5.7ĂÂ m/s respectively at height of 17ĂÂ m above ground level (AGL). The two sites are candidates for remote area wind energy applications. The Ouled Fayet and Marsa Ben M'hidi sites wind speed data indicated that the two sites have lower annual wind speed averages between 3.9-4.7ĂÂ m/s at 17ĂÂ m AGL. That makes the two sites candidates for installation of windmills to provide water for drinking and small scale irrigation purposes Brief description of the equipment, is also performed. Finally the aim of this work is only a preliminary study in order to assess wind energy analysis in Algeria and give useful insights to engineers and experts dealing with wind energy.Algeria Parameter Weibull Projects WAsP Wind energy
Review of wind energy use in Algeria
Most scientists now agree that human-induced global climate change poses a serious threat to both society and the Earth's ecosystems. Renewable energy holds the key to future prosperity and a healthy global environment and is considered as a promising way to solve the problem of environmental pollution such as major environmental accidents, water pollution, maritime pollution, land use and sitting impact, radiation and radioactivity, solid waste disposal, hazardous air pollutants, ambient air quality (CO, CO2, SOx, NOx effluent gas emissions), acid rain, stratospheric ozone depletion, and global warming (GHG). Solar, wind and hydrogen power can be considered as potential renewable energy sources in Algeria. The share of renewable energy sources in Algeria primary energy supply is relatively low compared with European countries, though the trends of development are positive. One of the main strategic priorities of New Energy Algeria (NEAL) which is Algeria's renewable energy agency (government, Sonelgaz and Sonatrach), is striving to achieve a share of renewable energy sources in primary energy supply of 10-12% by 2010. IEA projects that the fastest growing sources of energy will be supplied by renewables. Much of this capacity will be installed in developing nations where solar and wind electric power is already competitive. Clearly, the nation that can capture a leadership position has potential for substantial economic returns. The article presents a review of the present wind energy situation and assessed potential of wind energy sources in Algeria in particular the southwest region of Algeria (Adrar, Timimoun and Tindouf).Wind energy source Power production
Wind power potential assessment for three locations in Algeria
This paper utilized wind speed data over a period of almost 10 years between 1977 and 1988 from three stations, namely Adrar, Timimoun and Tindouf to assess the wind power potential at these sites. The long-term annual mean wind speed values along with the wind turbine power curve values were used to estimate the annual energy output for a 30ĂÂ MW installed capacity wind farm at each site. A total of 30 wind turbines each of 1000ĂÂ kW rated power were used in the analysis. The long-term mean wind speed at Adrar, Timimoun and Tindouf was 5.9, 5.1 and 4.3ĂÂ m/s at 10ĂÂ m above ground level (AGL), respectively. Higher wind speeds were observed in the day time between 09:00 and 18:00ĂÂ h and relatively smaller during rest of the period. Wind farms of 30ĂÂ MW installed capacity at Adrar, Timimoun and Tindouf, if developed, could produce 98,832, 78,138 and 56,040ĂÂ MWh of electricity annually taking into consideration the temperature and pressure adjustment coefficients of about 6% and all other losses of about 10%, respectively. The plant capacity factors at Adrar, Timimoun and Tindouf were found to be 38%, 30% and 21%, respectively. Finally, the cost of energy (COE) was found to be 3.1, 4.3 and 6.6 US cents/kWh at Adrar, Timimoun and Tindouf, respectively. It was noticed that such a development at these sites could result into avoidance of 48,577, 38,406 and 27,544ĂÂ tons/year of CO2 equivalents green house gas (GHG) from entering into the local atmosphere, thus creating a clean and healthy atmosphere for local inhabitants.Wind energy assessment Wind speed Plant capacity factor Wind farm Green house gases Renewable energy
Investigation of wind resources in Timimoun region, Algeria
This article presents an analysis of wind power resources in Timimoun region using the Wind Atlas Analysis and Application Program. This application takes in consideration the effects of sheltering obstacles, surface roughness changes, and the terrain variations on the wind speed variability and power output. The analysis part is composed of generating the wind speed and direction data for developing the wind atlas. Hourly wind data records over a period of 3 years from 2001 to 2003 were obtained from Société Nationale de l'Electricité et du Gaz R&D Office. The wind data measurements were made at an elevation of 17 m above the ground level. The mean values of wind speeds, wind power density, the predominant wind directions, the frequency distribution, and the Weibull distribution parameters (c and k) were determined. Finally, the energy yield was estimated using the VESTAS V90-2.0-MW wind turbine as the reference turbine in the southwestern region of Algeria, Timimoun. RETScreen model was also used to estimate the wind power potential employing the long-term annual mean wind speed data over a period of almost 22 years between 1984 and 2005. © The Author(s) 2016
Freeze-Dried Precursor-Based Synthesis of Nanostructured CobaltâNickel Molybdates Co 1
Advanced Symmetric Solid Oxide Fuel Cell with an Infiltrated K2NiF4-Type La2NiO4 Electrode
Advanced symmetric solid oxide fuel cells (SOFCs) with a reducible electrode were proposed. Specifically, La2NiO4 + La0.9Sr0.1Ga0.8Mg0.2O3-delta (LSGM) [or Sm0.2Ce0.8O1.9 (SDC)] composite electrodes were successfully fabricated by an infiltration method and tested for power generation. X-ray diffraction (XRD) results demonstrated there was no noticeable phase reaction between infiltrated La2NiO4 and LSGM (or SDC) scaffold, and scanning electron microscopy (SEM) analysis indicated that the La2NiO4 phase formed as nanoparticles that decorated the surface of the scaffold. Different from conventional symmetric SOFCs, the electrode material La2NiO4 of current cells was reduced under an anode atmosphere to form metallic nickel as a high active catalyst for fuel oxidation. After the reduction, the electrode morphology and geometric integrity were maintained for the infiltrated electrode. For thick electrolyte-supported symmetric SOFCs with infiltrated La2NiO4 electrodes, an attractive maximum power density of ~550 mW cm-2 was achieved at 800 °C operating on hydrogen fuel, significantly higher than similar cells with stable perovskite oxide electrodes, as reported in the literature. It suggested that the unreduced and reduced La2NiO4performed well as a cathode for the oxygen reduction reaction and as an anode for fuel electro-oxidation, respectively. In addition, a favorable operating stability was demonstrated for a symmetric SOFC with an infiltrated La2NiO4 electrode. It provides a new way for developing cost-effective SOFCs with huge application opportunities