Methods to Estimate Surface Roughness Length for Offshore Wind Energy

<div>Average wind speed profiles obtained with <svg height="9.4347pt" id="M245" style="vertical-align:-3.29111pt" version="1.1" viewbox="-0.0498162 -6.14359 11.2181 9.4347" width="11.2181pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M475 445L452 468C423 436 401 426 385 426S352 427 305 436C268 443 216 448 185 448C156 448 128 425 102 382C89 360 77 338 64 304L89 291C117 340 143 380 190 380C214 380 268 376 295 373C320 370 344 371 362 374L70 101C32 65 23 36 23 18C23 5 27 -3 31 -8C36 -8 39 -6 42 -1C52 15 67 31 80 40S110 49 143 33C195 8 257 -20 290 -20C339 -20 382 11 439 129L416 148C366 74 334 55 305 55C278 55 236 68 203 81C169 94 141 100 122 96C205 170 348 308 411 376L475 445Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,6.149,3.132)"><path d="M245 635C92 635 37 457 37 312C37 149 91 -12 244 -12C395 -12 449 166 449 312C449 469 395 635 245 635ZM243 598C332 598 358 454 358 312C358 173 334 26 245 26C158 26 128 174 128 313S152 598 243 598Z"></path></g></svg> estimates via the statistical method using 5 m wind speeds from buoy 44022 and 20 and 41 m from the CW Historical campaign to predict the wind speed at 60 m. Each of the three levels was tried as reference (5 m in red, 20 m in blue, and 41 m in green), and the best performance was with the 20 m level as reference.</div>

Advances in Meteorology

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Figure 7

Figure 7: Methods to Estimate Surface Roughness Length for Offshore Wind Energy 