Posters

Abstract

Problem to solve Several Floating Lidar Systems (FLS) have achieved The Carbon Trust Offshore Wind Accelerator (OWA) Roadmap Stage 3 maturity status meaning that a unit Pre-Deployment Verification (PDV) offshore is no longer mandatory. However, these validations are used to inform the FLS measurement uncertainty in a preconstruction energy assessment.  Developers that employ Stage 3 FLS will often choose to add a small amount of uncertainty to their project by not completing a PDV offshore to save the large mobilization costs of completing a four-to-six-week PDV as per the OWA Roadmap. However, there is no industry standard on how to quantify or replace this unknown measurement uncertainty in a preconstruction energy assessment. When this risk-based approach is utilized and no PDV is performed, this gap in the uncertainty model may lead to inaccurate wind measurement uncertainties in a windfarm preconstruction energy assessment when using Stage 3 FLS measurement data. Solution DNV has developed a new methodology to calculate FLS measurement uncertainty when a Stage 3 floating lidar has not undertaken an offshore pre-deployment verification. Harnessing a database of real-world floating lidar verifications, the envelope of significant environmental variables, classification results of the FLS and uncertainty requirements provided in the new IEC 61400-50-4, meaningful uncertainties to preconstruction energy assessment employing FLS are realized.  DNV has developed a numeric model and innovative methodology to assign a meaningful floating lidar measurement uncertainty to a wind resource assessment when a Stage 3 Floating Lidar does not complete a pre-deployment offshore verification. This will enable developers that employ Stage 3 FLS to better understand the difference in the choice to complete or not complete a PDV offshore so that they can appropriately meet project’s timeline, budgets, and lender requirements. It will also allow a better integration of the use of Stage 3 FLS in the offshore wind industry.