Preliminary analysis on the influence difference of the inland/offshore wind farms group on local turbulence intensity and wind shear exponent
Wind farms have obvious impact on the local climate. However, whether obvious differences on environmental effects of local wind between the inland and offshore wind farms still need to be explored. This article used the inland wind farms data from Shangyi, Hebei province and offshore wind farms in Rudong, Jiangsu province. Based on the data of meteorological observation and wind gradient tower around wind farm, the influence and comparative analysis on the inland and offshore wind farms on local wind environment, Turbulence Intensity (TI) and Wind Shear Exponent(WSE) were preliminarily analyzed. The results showed that the inland and offshore wind farms have significant effects on TI and WSE. The construction of inland and offshore wind farms has an enhancement effect on TI. The average annual TI increased by 31% and 37%, and the largest rise occurred in spring (47%) and winter (49%) in inland and offshore wind farms respectively. Moreover, the TI increasing range of high-level was greater than that in low-level, and greater at night than in day in inland wind. The TI increasing range was relatively smooth of different heights and diurnal variation in offshore wind farms. The construction of inland and offshore wind farms has significant differences effect on WSE. The WSE increased during the day and decreased at night, and the daily variation was significantly reduced and the average annual WSE decreased by 8%, the largest decline of WSE occurred in autumn (12%) at inland wind farms. The WSE increased obviously during the day and night with average annual WSE increased by 24%, and the largest rise occurred in spring (37%) at offshore wind farms .