Validation of a methodology for post-construction Energy Yield Assessment of an operational wind farm
M. Costa(1), T. Rocha(2), J. Mendonça(3), R. Pilão(4) and P. Pinto(1) 1. MEGAJOULE S.A., Maia (Portugal) 2. INESC TEC, Centre for Power and Energy Systems, Porto (Portugal) 3. SIIS, Instituto Politécnico do Porto, Porto (Portugal) 4. CIETI, ISEP Instituto Politécnico do Porto, (Portugal) 2026-01-20

Abstract

The uncertainty associated with the prospective Energy Yield Assessment (EYA) of a wind farm may be reduced by re-estimating the energy yield after it enters normal operation. This study aims to validate a simple methodology for conducting post-construction EYA of an operational wind farm. The proposed methodology derives a linear relationship between a historical source of wind speed data and the observed wind farm production on a monthly basis. In a first stage, the impact of different data sources on the accuracy of the Long-Term energy yield estimate was assessed. Results suggest that the determination coefficient R2 is a reliable indicator for selecting the most adequate source of historical wind speed data to be used in the Long-Term energy yield estimate. In a second stage, the model was validated from a statistical point of view by testing the premises of the linear regression model, namely the significance of the linear correlation (ANOVA test), and normally-distributed (Shapiro-Wilk test), non-self-correlated (Durbin-Watson), homoscedastic (Breusch-Pagan test) residuals. Results show these premises are verified for most test cases, indicating that the model is statistically robust that the model is statistically robust for most test cases.

Key words: Wind energy, post-construction Energy Yield Assessment, linear regression.

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