Transmission Tariff Allocation under high renewable source penetration and congestion conditions

This work provides a new Transmission Tariff Allocation (TTA) method to be applied in systems with high renewable source penetration and in different congestion conditions of the system. The method is based on the generalization of the Equivalent Bilateral Exchange and considers an optimization technique that aims to reduce the dispersion of the tariffs, keeping the desirable locational signal of existing TTA methods. In addition, a volatility analysis is provided, indicating that the new method is suitable for developing countries, where transmission tariff can change strongly due to the expansion of the system. Finally, a study verifying the importance of the optimal dispatch to define the tariffs is presented. The results indicate that it is important to clearly define the dispatch of the system, since it has strong impact on tariffs. A didactic 6-bus system is used to illustrate the proposed method and the IEEE 118-bus system is used to calculate the tariffs in a more realistic system. The proposed method is compared with other representative methods (Pro-Rata, EBE and Proportional Sharing), to highlight its qualities.