Environmental parameters effects on wind properties in Kermanshah province’s synoptic stations

An important step in the implementation of wind turbines is an assessment of the wind energy potential for relevant locations. This can be challenging because of the nature of the resource. The characteristics of wind energy, in terms of speed and direction, exhibit a high degree of temporal and spatial variability. The variability could lead probabilistic uncertainties, and these uncertainties might affect system operation significantly. The change in environmental parameters can greatly affect the wind characteristics. Therefore, determining the effect of environmental parameters on measured data is very important for determining the wind potential in locations and heights other than the point of measurement. However, in many studies, wind potential has been evaluated solely on the basis of data measured at synoptic stations and has been generalized to the surrounding area. This research aimed to assess environmental parameters effects such as roughness and obstacles on wind properties. To do this we used 3-hour wind speed and wind direction data acquired from synoptic stations, Digital Elevation Model, and land use map of Kermanshah province. Also the obstacles map has been prepared around every synoptic station using satellite imagery. WAsP software was used for estimation of wind properties in given conditions (0.03 m roughness and remove obstacles). In this way, wind properties from measured data in stations was compared with estimated wind properties for given conditions in 10 m AGL and so environmental parameters effects on wind properties was evaluated in all stations. Obstacles were identified around the all studied stations except for Tazehabad. Many obstacles were identified in the direction of the second prevailing winds (western winds) at Sarpol Zahab and Ravansar stations and in the direction of the north of the station at Javanrood and Sararood stations. The highest obstacles (with an average elevation of more than 10 meters) are also observed at in Kermanshah (northwest and north-east), Eslamabad-Qarb (west and southwest), Kangvar (south, southeast) and Harsin (east) stations. The result showed that the most induced environmental parameters effects change in mean wind speed occurred in Eslamabad-Qarb, Ravansar, Sarpol-Zahab, Kermanshah (30% to 40% respectively) and the least change of it was occurred in Harsin, Tazeabad and Somar (9% to 15%). The percentage of change in wind speed at other stations is equal to 28% at Gilanqarb, 26% at Sararood, 26% at Javanrood, 20% at Sonqor, 18% at Qashisharin, and 16% at Kangavar. Mean wind power density was changed between more than 81% in Ravansar and Eslamabad-Qarb to 27% in Harsin. The percentage of change in mean wind power density at other stations is equal to 66% at Sarpol-Zahab, 65% at Kermanshah, 64% at Sararood, 63% at Javanrood, 62% at Gilanqarb, 49% at Qashisharin, 48% at Sonqor, 38% at Tazeabad, 37% at Somar and 33% at Kangavar. Thus many obstacles in wind dominates direction in Ravansar, Sarpol-Zahab, and high obstacles in Eslamabad-Qarb and Kermanshah and also high roughness value in Kermanshah, Ravansar, Eslamabad-Qarb, Javanrood and Gilanqarb has great impact on wind speed decrease to more than 26% and wind power density to more than 62%. As a result, it can change priority of suitable places for using wind energy if we ignore environmental parameters effects on wind measured data.