With the functioning of the electric power market all participants in the market sell and buy electric power on the united equilibrium price. United equilibrium price for all participants of market can’t be established to be upon consideration of system limitations. Their individual equilibrium prices, called nodal price, correspond to different generator and load units. In the work is ilustrated possibility of the nodal prices calculation for load nods with the aid of the indeterminate Lagrange multipliers based on the example of the electric power system test scheme. The corresponding optimization problem of the linear programming preliminarily is solved for the revealing of active limitations to the variables.