Electrical energy losses in the electromagnetic grid are a physical phenomenon and during the operation of the electrical energy system they can not be avoided. One of the most significant issues of the economics of electrical energy grid’s operation it the one concerning the determination of the origin and amount of losses, and it appears in transmission as well as in distribution electrical energy grids. Special attention needs to be dedicated to determination and analyses of losses in the electrical energy grid in order to reduce the losses to acceptable technical and economic levels. Although the issue of losses was always actual, special attention is being dedicated to it in the past few years considering the sensitive issues of restructuring and introduction of market relations in the electrical energy sector. Current nonmarket manner of supplying energy for covering losses in electrical energy grids is abandoned and a market mechanism is introduced, which poses a particular challenge to the relevant operators for at least two reasons: 1) the level of electrical energy losses in the grids can not be precisely predicted, 2) the cost of energy supply for covering the losses is variable, in line with market trends in electricity prices, while at the same time the business of the competent operators is strictly regulated. Both of these reasons represent the issues this proposed work will address. When the Republic of Croatia entered the European Union it adopted European energy directives. The reduction of grid losses and their coverage represent a significant aspect in achievement of the European Union's goals related to the liberalization of the market, reduction of overall losses in the common European electrical energy system and ultimately in increasing the efficiency of the electrical energy sector’s drive. Speaking of the common goal, electrical energy losses are often the subject of various professional and business discussions in Europe, with particular attention being given to the complex issue of dividing losses in technical and non-technical and to the manner of energy supply for covering losses. For this reason the lost electrical energy in the electrical energy grids has its technological, economic and ecological weight and because of it, losses of electrical energy, and also the supply of electrical energy for covering losses, are becoming one of the most important business objectives of the power sector.