Case 1: Wind farm gains 4.23% AEP across +150 WTGs Reaping the benefits of strong wind resources To get the most out of strong wind resources, wind farm owners choose turbines that are designed to perform optimally under such climatic conditions. However, even the best suited turbines will not capture the full potential of the available energy unless they are tuned to match the site-specific climate. As a site-specific upgrade, Extended Cut Out can improve the power capture significantly during high wind speeds. At sites with highly beneficial wind distributions, the AEP gain captured in the power curve can be as high as 5%. An example of this scenario is presented here, where a wind farm consisting of more than 150 V100-1.8MW turbines has been upgraded with Extended Cut Out. Based on a wind power plant assessment carried out with Vestas SiteCheck® tools, the cut out speed was increased from 20 m/s to 25 m/s, while the re-cut in speed was increased from 18 m/s to 23 m/s. AEP gain from energy capture in high wind speeds In the case at hand, the validated AEP gain is 4.23%. This is a significant AEP gain, which is only achievable at sites with very favorable wind speed distribution. Moreover, the gain is derived from two different, yet related, benefits of the Extended Cut Out upgrade. Firstly, the increased cut out speed allows the turbine to operate at wind speeds that the original cut out speed would have protected it against. With a propitious wind speed distribution, this increases production relatively more than at a site with lower wind speed averages. A significant amount of additional production hours in the wind speed interval between 20 m/s and 25 m/s was enabled due to the upgrade. This part of the gain is what can be identified in the new power curve. Specification of upgrade Turbine model Number of turbines Original cut out speed Original re-cut in speed Extended Cut Out speed New re-cut in speed Validated AEP gain Data training period Data testing period V100-1.8MW +150 20 m/s 18 m/s 25 m/s 23 m/s 4.23% Jun 14 - Dec 14 Jun 15 - Dec 15 Climatic conditions at the site Normal Wind Conditions (annual) Weibull A parameter Weibull k parameter Site hub height avg. WS Turbulence intensity (TI15) (avg.) Turbulence intensity (TI15) (std.) Average wind shear Average inflow angle Extreme Wind Conditions (50 year) Extreme WS (10 min. avg.) TI at extreme WS Survival (2 second gust) WS Temperature and Air Density Average temperature Min. temp., P1 Max. temp., P99 Avg. air density 8.9 m/s 1.9 7.9 m/s 6.3 % 2.7 % 0.22 1° 39.6 m/s 7.2 % 48.2 m/s 4.9 ° C -22.7 ° C 35.4 ° C 1.120 [kg/m3] 4 PowerPlusTM Case study Extended Cut Out
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