Utilization time of maximum power losses (UTL) has been applied for determination of energy losses in power grids. UTL is a parameter allowing for accurate estimation of energy losses. Using the maximum load time for UTL determination, better results can be achieved by decomposing the load duration graph (LDG) into two parts: the base and the delta ones. Bearing in mind that the latter occupies a smaller area of the entire LDG, the goal is achieved, since the errors can be caused only by the inaccuracy of delta part calculation. Based on this method it is possible to calculate UTL directly from the load graph and to achieve the same accuracy as with the classical method and with the smaller number of load measurements needed. By modifying this method once again, we can estimate UTL from the load graph based on its bearing points which are bending and flex points of the load time curve. The load time graph is decomposed into columns, each of them being contained between two neighboring bearing points. The UTL of each column is calculated to obtain the total UTL, which is the sought for value. The UTL of a column takes into account the minimum load value within the column, the maximum load time and the UTL of its upper part, both of the last quantities depending on the degree of the load curve diversion from a straight line.