The low-voltage distribution network feeds a significant number of non-linear loads, resulting in a distorted and unbalanced condition. A negative effect of these states is the increase in power losses in the elements of the distribution network. The article examines the power losses for low-voltage distribution networks in the harmonic loading condition. Even if you first look at the symmetrical sinusoidal state for the power loss, this often leads to an overload of the power lines, especially the neutral conductor. Due to the various harmonics that affect the low voltage distribution grid, they should pay more attention to the collected data. This data should be processed with efficient data-driven algorithms and used in power losses estimation. The aim of this article is the effects of harmonic currents on power losses evaluation for a proactive operation of the low voltage distribution grid using a Ward's Hierarchical Clustering Method. To validate the proposed methodology, a real low voltage distribution grid was considered, the proposed approach has been tested and obtained results confirmed their efficiency.