Use of marginal loss coefficients for assessment of transactions in electrical transmission systems

The introduction of Third Party Access in the European electricity market as a basic element of competition offers the right of using foreign grids for the transmission of electricity. Thus methods of transmission pricing are, among other things, required to allocate costs according to the extent of use of the electrical network. Considering this demand the use of marginal loss coefficients for assessment of transactions in transmission systems is discussed in this paper. Investigations based on large numbers of simulations of transactions in the German transmission system show, that a high accuracy can be achieved by using marginal loss coefficients in combination with an approach of superposition.