# Can LiDARs Replace Meteorological Masts in Wind Energy?
## 5 Conclusions  
The current paper presented the results from a year-long Doppler LiDAR-based measurement campaign with the primary goal of providing an answer to the question of whether a single LiDAR can replace the meteorological tower for wind energy applications. Wind data measured by a profiling LiDAR was compared against those measured using sonic and cup anemometers mounted to a neighboring meteorological mast. LiDAR-measured wind speeds showed very good agreement with those measured using the sonic anemometer, though the variation in the comparison of the standard deviations was higher than that for the mean wind speeds. The bin-averaged turbulence intensities showed that compared to the cup anemometers, the LiDAR-measured turbulence intensity was closer to the sonic anemometers measurements. Thus, the fatigue load computed using the LiDAR-measured turbulence will be more reliable than that computed using the turbulence measured by the cup anemometers. Furthermore, the gust factor obtained from the sonic anemometer-measured and LiDAR-measured peak wind speed roughly converged to 1.9 showing that the LiDAR is able to measure peak wind speeds with acceptable accuracy (at least up to 57 m height considered in this study). To investigate the applicability of LiDAR in moderately complex terrain, the measurements were divided into those blowing from the homogeneous terrain sector and those blowing from the complex terrain sector. When compared against the sonic anemometer measurements, both the homogeneous and complex terrain data sets showed good agreement. Thus, it can be concluded that--even with the classical DBS mode of measurement--LiDAR-measured wind speeds can be considered to be accurate for moderately complex terrain. Comparison of the velocity distribution showed that for lower wind speeds (\(\overline{V}<5\) m/s), the frequency of occurrence for the LiDAR measurement was lower than that for the sonic anemometer, although for \(\overline{V}\geq 5\), the LiDAR measurement showed a slightly higher frequency of occurrence. Figure 18: Comparison of DELs computed using the distribution of wind speed and turbulence intensity of the sonic anemometer and the LiDAR measurements. (**a**) DELs for the blade root bending moment; (**b**) DELs for the tower base moment; (**c**) Lifetime DELs (vertical line separates the blade root and the tower base moments). The difference in the occurrence frequency of power distribution between the two devices for all power production bins was less than 1%. Finally, fatigue loads for wind speed and turbulence distributions for the two devices were assessed in the form of DELs. It was found that the LiDAR measurement overestimated the lifetime DEL by 2%-6% for the blade root bending moments and by 11%-13% for the tower base bending moments. This study shows that even with the inherently lower data availability and some shortcomings of the classical DBS technique, profiling LiDAR can measure wind speed and turbulence intensity with acceptable accuracy and, therefore, can be deployed for actual wind energy applications. The long-term measurement campaign conducted in this study shows that such measurements can be influenced by a lot of parameters which were not considered in the current study. In future studies, atmospheric stability and other environmental conditions such as snow and rain should also be considered. In addition, measurements at sites with different degrees of complexity and offshore sites will also be important. [PERSON] and [PERSON] jointly set up the study; [PERSON] performed most of the data analyses; [PERSON] performed analysis of terrain complexity of the measurement site and reconfirmed several analyses; [PERSON] was responsible for collecting information related to IEC standard and organizing paper according to the requirements of the standard; [PERSON] wrote the manuscript; all the authors read, reviewed and provided valuable and critical input for the manuscript.