Posters

Abstract

Introduction: Whilesome LiDAROEMs have reached the commercial statusfor deployment in benign sites, it is stillcommon practicetovalidateLiDARspre-/post-deploymentnext tocup-anemometer equipped windmasts,toensurebank-grade measurements.Mainstreamdecided to review all itsground-mountedLiDAR validations(22)to see ifthis practice isstill justifiable andadding value. Industry-adoptedguidance only exists forfloating LiDARvalidations, in the form of theCarbon Trust OWARoadmapv2.0(OWAR2.0).This guidanceisalso applied to ground-based LiDARvalidations,supplemented byengineer's judgement.OWAR2.0definestheKey Performance Indicators(KPI)whichspecifythe required minimum level of performance to be achievedby the LiDAR unit to beclassified as aStage3device. Method: This study examined 22of Mainstream'sonshoreLiDARvalidation resultsacross Chile, South Africa, and Vietnam, coveringa period from May 2018 untilJanuary 2023,withelevenZX LidarsZX300andelevenLeosphereWindCubev2.0/v2.1validation campaigns.Theresultswere reviewed according to the pass/fail criteria within each KPI, and further studied according to the absolute values obtained from the validations against the KPI accepted ranges.Further analysisbytheLiDAR model, the region where the validation took place, andthevalidation completion datewas performed. Results: Therewereno validationspassingall validation criteria,with5 out of 22validationspassingless than60%criteria, andonly2 out of 22passingover90%criteria.Certain criteriahadfrequentlylow pass rates of 14% and 23% for'Data recovery(centred17m/s +)'and'Mean wind direction offset(all wind speeds)'respectively.The performance of LiDARs over time showed no significant trends,indicatingconsistent performance.Somedifferences in performance wereobservedacrosssomecategories(groups of criteria)thoughnoconcerningextremeswereobserved. In the'Direction slope'category, the most notable difference was seen between the LiDAR models, with52% and 70%pass rate fortheZX LidarsandLeosphererespectively.In the'Mean wind directionR2' category, there was a 64% and 91% pass rate for theZX Lidar and theLeosphererespectively. Thismight be explained by theZX LidarsZX300havinga wind rose split and correction mechanism (requireddue to the180°uncertainty from non-heterodyne laser)resulting ina less reliable wind rose compared toLeosphere.Lastly,ZX Lidarshadhigher observed data recoveryKPI ratesin windier sites. Conclusion: Based onthis review of theLiDARvalidation results,Mainstream decided to continue the practice of onshore pre-deployment validationsinsimplesites.NeitherLiDAR model showed significant changes invalidation results over time, showing consistency and a similar level of scattering around theaccepted ranges of KPI's.An industry standard set of KPI's for LiDAR onshore wind measurements, or a joint standard for onshore and offshore LiDARs, could prove highly beneficial in ensuring uniformity in measurements globally.