Full Title: Offshore Energy Assessment Validation
Author(s): DNV
Publisher(s): DNV
Publication Date: March 24, 2023
Full Text: Download Resource
Description (excerpt):
DNV has been producing Energy Production Assessments (EPAs) of proposed wind farms for over 35 years and has developed a well-defined methodology that is continually updated as new research and information becomes available. Validations serve a dual purpose: they provide DNV with a feedback loop used to direct methodology improvements and provide the industry with valuable insights into the levels of accuracy achieved by DNV’s current best practice.
The results show a slight negative bias in the prediction of P50 energy output and show some spread in project performance relative to the pre-construction prediction. Overall, the risk of projects underperforming their estimate is greater than their chance of overperforming. There are a few possible explanations for the bias. External factors, such as grid curtailment and balancing payments, are expected to have contributed, along with operational issues impacting turbine availability and performance, some of which will have been accompanied by financial compensation.
Further recommendations are made on improvements that can benefit both project development and operations and these should be considered carefully by all industry stakeholders. In addition to the above, DNV is implementing changes to its Large Wind Farm Recovery Settings for offshore energy assessments based on recently completed research increasing the wake recovery parameter to 120 rotor diameters for offshore projects. It is noted that the projects included in this validation were not impacted by this change given that there are no projects in the vicinity of those included in the validation data set.