Case study

Operational performance assessment of a wind farm

We completed a power curve performance analysis and energy yield assessment (EYA) for one of our clients’ onshore wind farms.


We completed an operational performance assessment, including power curve assessments, and compared this with our client's initial Energy Yield Assessment (EYA) for the project. The objective of this work was to resolve discrepancies between the observed performance of the wind farm and that budgeted for in the initial EYA, to provide an independent perspective on the respective methodologies employed.

Our work

We initially worked to understand how to effectively process the available data, accounting for the various uncertainties associated with the analysis process (i.e., wind speed correction from met mast data applied to nacelle anemometer data, as well as air density corrections). This allowed us to create individual wind farm power curves as a function of free-stream velocity and map these measured results back to the initial EYA methodology, as stated in the business case.



Our in-house, open-source development tools facilitated a quick turnaround of results and analysis which directly fed into key decision-making metrics. We were able to generate the operational metrics for wake loss, electrical loss, availability, turbine performance and observed wind climate, which we then compared to the assumptions in the pre-construction EYA. This helped the client update its forecasts and plan some inspection activities to further understand the origins of the differences.

Monitoring, reviewing and then updating these metrics over time will provide a valuable insight into where issues/uncertainties may lie, meaning that any further investigations required will be highlighted earlier, to ensure appropriate mitigation of risk throughout the lifetime of the wind farm.

Work with Frazer-Nash

Get in touch and let us help with your next project