Introduction, it is common practice for wind energy consultants to assume that all uncertainty components are uncorrelated, and combine them using Equation \[unc\_unc\] to obtain $\sigma_{\text{tot,uncorr}}$. To test the validity of this assumption, we apply Equation \[unc\_unc\], in which each of the five considered uncertainty components $\sigma_i$ is quantified as the coefficient of variation of the corresponding operational AEP distribution obtained by running the Monte Carlo simulation with a single sampling performed. We note that the same values of $\sigma_{\text{tot,uncorr}}$ would be obtained by running the Monte Carlo simulation with, at each iteration, all of the five samplings performed, independently from each other.

We contrast the total AEP uncertainty calculated assuming uncorrelated components with what we obtain by taking into account these correlations in the calculation. Following the guidance in @iso1995guide, we combine the various uncertainty components and calculate the total long-term operational AEP uncertainty for each wind plant as: $$\sigma_{\text{tot,corr}} = \sqrt{\sum_\text{i=1}^\text{N} \sigma_\text{i}^2 + 2 \sum_\text{i=1}^\text{N-1} \sum_\text{j=i+1}^\text{N} R_\text{ij} \sigma_\text{i}  \sigma_\text{j} }
    \label{unc_corr}$$ where, in our analysis, $N = 5$ and $R_\text{ij}$ is the correlation coefficient between each pair of uncertainty components calculated from the results obtained for all 472 wind plants considered in the analysis.

The comparison between $\sigma_{\text{tot,uncorr}}$ 