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| Titel: |
Alterations of potential wind energy with height and parts of the day |
| Auteur: |
Károly Tar Sándor Szegedi |
| Verschenen in: |
Journal of electrical and electronics engineering |
| Paginering: | Jaargang 2 (2009) nr. 1 pagina's 206-210 |
| Jaar: |
2009 |
| Inhoud: |
According to studies on the planetaryboundary layer the theoretical logarithmic windprofile law can give a good approach of wind speedat heights over 100 meters above the ground and atgreater heights in periods of close to neutral orweakly unstable atmospheric situations, that ismainly daytime. The value of exponent of simplifiedversion of this law is constant for practical use determinedmainly by the roughness of the surface.Due to its simplicity this law is widely used in energeticwind measurements for converting wind speedsmeasured near the ground to the height of the windturbines. However the value of the exponent is determinednot only by the roughness of the surface,but numerous atmospheric factors like stabilityconditions, for example, as it was proved by thestudies on the wind energy potential of Hungary.For this reason if the diurnal course of the exponentis neglected and a constant value is used for it theerror of the estimation will increase in case of closeto the surface inversions (strongly stable conditions)especially in the night. Results of our examinationson the seasonal characteristics of the diurnalcourses of the exponent what determines the estimatedchanges of the wind speed with the height arepresented in this paper. Our method is demonstratedon the wind speed datasets of the meteorologicaltower of Paks for the year of 2000-2001. There arewind speed measurements at three levels (20, 50 and120 meters) on the tower with the 10 minutes averagesregistered. On the base of our examinations itcan be claimed that there is a turn in the dailycourse of potential wind energy over the inflexionheight that is, there is more utilizable wind energyduring the night than in the day. Naturally, thesame is true for the electricity produced from windenergy. |
| Uitgever: |
Editura Universităţii din Oradea (provided by DOAJ) |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 5 van 50 gevonden artikelen
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