Posters

Abstract

Wind measurement is governed by the IEC 61500-50 series of standards. This provides a basis for reliable measurements that support consistent wind assessment methodologies, inter-comparable estimates of key parameters relating to incident resource, power performance, site suitability, uncertainty evaluation, and other key considerations, amenable to independent review as required for the delivery of all phases of wind energy project development. Standards undergo maintenance cycles to ensure they reflect and codify current industry understanding regarding best practice. In addition, new standards are developed and added to the series as new measurement technologies are adopted by the wind industry.   Currently the standards from IEC 61400-50-1 to 50-4, covering met masts, ground based remote sensing, nacelle mounted lidars, and floating lidars, are being reviewed and revised by a maintenance team of experts nominated by national standards institutes. In addition, the publication of the first edition of 50-4 (floating lidars) is expected soon. A 50-5 standard is under development to provide guidance for the use of scanning lidars. This presentation provides an update on the status of wind measurement standards and reviews the most recent developments emerging from the ongoing process of maintaining and developing wind measurement standards. In addition, these standards will be placed in the broader context of related guidance on measurement models provided by JCGM (e.g., GUM Part 6) and the forthcoming guidance on model validation, IEC PAS 61400-60 (PAS 60). The question remains: what do our wind measurements mean? How can we perform measurements as effectively as possible? How do they increase the value of my project? What role can they play in the broader digital integration of our energy infrastructure? Can we define a “digital twin” of the wind that is compatible with other digital assets, based on our measurements? The series of standards has grown to accommodate the adoption of a greater variety of measurement technologies. A key challenge in maintaining the standards is to ensure consistency in uncertainty evaluation, i.e., that if different measurements of the same wind conditions provide different uncertainties, these reflect genuine differences in the performance of the technologies and are not artefacts of inconsistencies in the guidance. Previously it was assumed uncertainty budgets were complete. Recent standard development acknowledges this is not possible, as the likelihood of an unforeseen influence on accuracy cannot in principle be accommodated. Therefore, the ACARA principle (As Complete As Reasonably Achievable) is adopted. This states that, if an unforeseen influence is encountered during a measurement campaign, the classification and calibration process has been undertaken in a manner that means it could not reasonably have been foreseen. The possibility of a unifying framework that can achieve this consistency is emerging. For example, instrument classification may be considered the validation of a measurement model described in accordance with GUM-6 using methods described in PAS 60. This presentation will explore these possibilities.