This paper discusses the article “Assessing temporal complementarity between three variable energy sources through correlation and compromise programming.” The discussed paper proposes a novel method of assessing complementarity between three energy sources using correlation, compromise programming, and normalization. The method is then used to calculate a complementarity index which is applied to a case study in Poland. However, upon inspection, the normalization of the index overestimates the complementarity potential. This issue is discussed in detail in this paper, and an alternative way of calculating the index is proposed, eliminating the issue of overestimating complementarity.