The article is devoted to the analysis of losses in functioning transmission lines of electric energy and identifying opportunities for reduction of these losses. It is shown that on average in the world in transmission lines about 5% of generated electricity is lost, which in absolute values is more than 1300 TWh. Based on real data from 15 power lines of Ukraine, it was revealed that losses in them are on average 13.3%, and in absolute values - 19.1 TWh. To reduce these losses, it is proposed to use the operation of power lines in a matched load mode. The modeling carried out for this mode showed the possibility of reducing losses to 1.78%. To achieve matched load mode, it is proposed to use compact controlled high-voltage power lines. The principles of operation of these lines are considered and ways of their practical implementation using IoT technologies are identified.