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001-es BibID:	BIBFORM010346
Első szerző:	Tar Károly (klimatológus)
Cím:	Alteration of potential wind energy with height and parts of the day / Tar Károly, Szegedi Sándor
Dátum:	2009
Megjegyzések:	According to studies on the planetary boundary layer the theoretical logarithmic wind profile law can give a good approach of wind speed at heights over 100 meters above the ground and at greater heights in periods of close to neutral or weakly un-stable atmospheric situations, that is mainly day-time. The value of exponent of simplified version of this law is constant for practical use determined mainly by the roughness of the surface. Due to its simplicity this law is widely used in energetic wind measurements for converting wind speeds measured near the ground to the height of the wind turbines. However the value of the exponent is determined not only by the roughness of the surface, but numerous atmospheric factors like stability conditions, for example, as it was proved by the studies on the wind energy potential of Hungary. For this reason if the diurnal course of the exponent is neglected and a constant value is used for it the error of the estima-tion will increase in case of close to the surface inversions (strongly stable conditions) especially in the night. Results of our examinations on the seasonal characteristics of the diurnal courses of the exponent what determines the estimated changes of the wind speed with the height are presented in this paper. Our method is demonstrated on the wind speed datasets of the meteorological tower of Paks for the year of 2000-2001. There are wind speed measurements at three levels (20, 50 and 120 meters) on the tower with the 10 minutes averages registered. On the base of our examinations it can be claimed that there is a turn in the daily course of potential wind energy over the inflexion height that is, there is more utilizable wind energy during the night than in the day. Naturally, the same is true for the electricity produced from wind energy.
Tárgyszavak:	Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban potential wind energy exponent of Hellman-law seasonal characteristics of the exponent
Megjelenés:	Journal of Electrical and Electronics Engineering. - 2 : 1 (2009), p. 206-210. -
További szerzők:	Szegedi Sándor (1970-) (klimatológus)
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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