Power of One-Way ANOVA
The power of one-way ANOVA is the probability of rejecting
$$ H_0: \mu_1 = \cdots = \mu_k $$when the treatment means are not all equal.
Under the alternative, the ANOVA $F$ statistic follows a noncentral $F$ distribution. Power therefore depends on the true treatment means, the common within-group variance, and the group sample sizes.