00345 Cat litter containing dry mining coal

07 required. The parameters that are mostly used are the mean wind speed or the total wind energy output (primary parameters). It is, however, shown in the present study that one cannot judge the suitability of the functions based on the primary parameters alone. Additional parameters (secondary parameters) that complete the primaly parameters are required to have a complete assessment of the fit, such as the discrepancy between the measured and fitted distributions, both for the wind speed and wind energy (that is the standard deviation of wind speed and wind energy distributions). Therefore, the secondary statistical parameters have to be known as well as the primary ones to make a judgement about the suitability of the distribution functions analysed. The primary and secondary parameters are calculated from the 12-month of measured hourly wind speed data and detailed analyses of wind speed distributions are undertaken. 04/00345 Cat litter containing dry mining coal Morgenstern, I. Ger. Offen. DE 10,132,495 (Cl. AOlK23/00), 30 Apr 2003, Appl. 10,132.495. (In German) The cat litter contains a grainy and porous material especially dry mining coal. The mining coal is used prior the flotation and thereby has an increased content of quartz. The mining coal can be used as well as fertilizer carrier. 04100346 Computer-aided design of PVIwind hybrid system Ai, B. et al. Renewable Energy, 2003, 28, (lo), 1491-1512. A complete set of match calculation methods for optimum sizing of PVI wind hybrid system is presented. In this method, the more accurate and practical mathematic models for characterizing PV module, wind generator and battery are adopted; combining with hourly measured meteorologic data and load data, the performance of a PV/wind hybrid system is determined on a hourly basis; by fixing the capacity of wind generators, the whole year’s LPSP (loss of power supply probability) values of PViwind hybrid systems with different capacity of PV array and battery bank are calculated, then the trade-off curve between battery bank and PV array capacity is drawn for the given LPSP value; the optimum configuration which can meet the energy demand with the minimum cost can be found by drawing a tangent to the trade-off curve with the slope representing the relationship between cost of PV module and that of the battery. According to this match calculation method, a set of match calculation programmes for optimum sizing of PV/wind hybrid systems have been developed. Applying these match calculation programmes to an assumed PV/wind hybrid system to be installed at Waglan island of Hong Kong, the optimum configuration and its hourly, daily, monthly and yearly performances are given. 04/00347 Determination of Angstrom’s turbidity coefficient over Thailand Janjai, S. et al. Renewable Energy, 2003, 28, (11), 16X5-1700. Values of the Angstrom’s turbidity coefficient, @, at 53 meteorological stations covering Thailand were determined by using three different methods. A selection of the methods was based on input data available at each station. It was started with the calculation of p at Nakhon Pathom (13.81”N and 100.4”E) using narrow-band spectral irradiance data obtained from a multi-filter rotating shadow band radiometer. Langley’s method was employed to calculate 4 from the spectral data. The values of p derived from this method were used as references to validate a method for computing p from broad-band direct irradiance proposed elsewhere by Louche et al. It was found that this method was valid for a tropical climate. Then Louche et 01,‘s method was used to calculate B at meteorological stations situated at four main cities, namely Chiang Mai (18.78”N, 98.98”E) located in the north, Ubon Rachathani (15.25”N, 104.87”E) in the northeast, Songkhla (7.20”N, 100.60”E) in the south and Bangkok in the central region. Based on vaiues of ,a of these cities, a new model relating to visibility, suitable for the tropical climate was developed. This model was used to estimate 0 at the other 48 meteorological stations where the visibility was routinely observed. Finally, seasonal variations of 0 were investigated. It was found that for the stations in the north, the northeast and the central region, the values of p are relatively high in the dry season (November-April). They decrease in the wet season (May-October). For most stations in the south, /? was relatively low and remained nearly constant all year round. It was also inferred that the northeast monsoon and the southwest monsoon had a strong influence on the seasonal variations of l3. 04100348 Economics of off-shore/on-shore wind energy systems in Qatar Marafia, A-H. and Ashour, H. A. Renewable Energy, 2003, 28; (12), 1953-1963. This work presents an assessment of the potential and economicai feasibility of adopting off-shore/on-shore wind energy as a renewable source of energy in Qatar. An analysis is presented for the long term measured on-shore wind speed (1976-2000) at Doha International Airport. A similar analysis is presented for the measured off-shore

Alternative

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wind speed at the Qatari Haloul Island. For the on-shore measurements, the average annual wind speed (at 20 m height) was found to be about 5.1 m/s. On the other hand, for the off-shore measurements at Haloul, the average annual wind speed was found to be about 6.0 m/s. This result indicates the suitability of utilizing small to medium-size wind turbine generators, efficiently. Such generators can be implemented for water pumping and to produce sufficient electricity to meet vital, limited needs of remote locations, such as isolated farms, which do not have access to the national electricity grid. An economical assessment is presented which takes into consideration the interest recovery factor, the lifetime of the wind energy conversion system (WECS), the investment rate and operation and maintenance costs. The results indicate that the cost of electricity generation from the wind in Qatar compares favorably to that from fossil fuel resources. The feasibility of utilizing off-shore wind turbine systems to meet the power requirements of the island of Haloul and possibly provide additional power for nearby on-shore areas is discussed. 04/00349 Hourly wind speed analysis in Sicily Bivona, S. et al. Renewable Energy, 2003, 28, (9), 1371-1385. The hourly average wind speed data recorded by CNMCA (Centro Nazionale di Meteorologia e Climatologia Aeronautica) have been used to study the statistical properties of the wind speed at nine locations on Sicily. By grouping the observations month by month, it is shown that the hourly average wind speed, with calms omitted, is represented by a Weibull function. The suitability of the distribution is judged by the discrepancies between the observed and calculated values of the monthly average wind speed and of the standard deviation. 04/00350 How California hopes to manage the intermittency of wind power Asmus, P. The EkfricitJl Journal, 2003, 16, (6), 48-53. California’s Participating Intermittent Resources Program hinges on the notion that there can be a way to schedule wind energy in future markets without imposing large penalties upon wind projects when they do not deliver energy as forecasted. 04/00351 Statistical bivariate modelling of wind using firstorder Markov chain and Weibull distribution Ettoumi, F. Y. et al. Renewable Energy, 2003, 28, (11), 1787-1802. This paper studies the statistical features of the wind at Oran (Algeria). The data used are the wind speed and wind direction measurements collected every 3 h at the meteorological station of Es Senia (Oran), during the 1982-1992 period. The eight directions of the compass card have been considered to build the frequency distribution of the wind speed for each month of the year and each direction. The three-hourly wind data have been modelled by means of Markov chains. First-order nine-state Markov chains are found to fit well the wind direction data, whereas the related wind speed data are well fitted by first-order threestate Markov chains. The Weibull probability distribution function has also been considered and found to fit the monthly frequency distributions of wind speed measurements. Two methods of wind data retrieval are thus made available. In fact, two models of chronological bi-series are obtained describing wind speed and wind direction. 04/00352 The potential for electricity generation from onshore wind energy under the constraints of nature conservation: a case study for two regions in Germany Krewitt, W. and Nitsch, J. Renewable Energy, 2003, 28, (IO), 1645-1655. In spite of the well-acknowledged environmental benefits of electricity generation from wind energy, there is increasing concern about impacts from wind turbines on local ecosystems and on the natural scenery. A GIS-based approach is developed to analyse the effect of different nature conservation criteria on the wind energy potential in quantitative terms. Results for two case study regions in Germany, representing a coastal area with quite good wind conditions and an inland region with limited wind resources, illustrate to which extent the ban of wind turbines in, for example, landscape conservation areas, special bird protection areas, or areas with high visual sensitivity reduces the potential for electricity generation from wind energy. It was concluded that even under strict nature conservation constraints there is still a large potential for on-shore wind energy use that can be used to establish a sustainable electricity supply in Germany. 04/00353 Transient stability of a fixed speed wind farm Ledesma, P. et al. Renewable Energy, 2003, 28, (9), 1341-1355. A typical fixed speed wind farm connected to a simple grid is modelled. Using this model, a three-phase fault is applied close to the wind farm, and cleared by disconnecting the affected line. The effect of several electric, mechanical and operational parameters on the critical faultclearing time of this base case is evaluated and discussed. The studied parameters are the short-circuit power at the connection bus, the reactive power compensation, the distance to the fault, the rotor inertia, the hub-generator resonant frequency, the wind speed and the Fuel

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