Comparison of two methods for long-run marginal cost-based transmission use-of-system pricing

Two methods that provide geographically differentiated transmission usage t ariffs, based on the long-run marginal cost of transmission, are presented and compared: investment cost-related pricing and the: DC load flow pricing . The basic assumptions and approximations behind their design are analysed . Very efficient implementations of both methods, based on sensitivity anal ysis, are presented. Both methods are applied to the computation of transmi ssion usage tariffs in the Greek power system, and the resulting tariffs ar e compared.