Call for entries from companies and consortia interested in undertaking a study for the OWA Yield and Performance Technical Working Group (TWG-Y) to investigate the current state-of-the-art Energy Yield Assessment Uncertainty methodologies, assumptions and uncertainty contributors. The study will document and assess current and new methodologies and their suitability through desk-based research and stakeholder engagement, forming the basis for establishing a pre-construction EYA uncertainty baseline to quantify future uncertainty improvement against a credible and industry-accepted baseline.

The objectives of this study are to:

• Establish a 2026 baseline for pre-construction EYA uncertainty by reviewing current industry methods, assumptions and uncertainty propagation approaches across wind resource, gross yield and technical losses.
• Test and evidence current industry practice using representative 1GW offshore wind farm case studies and an anonymised round-robin exercise to compare how uncertainty is assessed across organisations.
• Develop and publish a framework and uncertainty baseline which enables OWA partners and the wider industry to compare, evidence and publish future uncertainty quantification improvements.

The deadline for clarification questions is 12 June 2026 at 13:00 BST.

The closing date to receive tender submissions is 15 July 2026 at 16:00 BST.

All clarification questions and tender submissions should be sent electronically, by their respective deadlines, to maria.gonzalez-martin@carbontrust.com and mary.harvey@carbontrust.com.