New Australian NEM transmission use of system charging methodologies for integrating renewable generation to existing grid

The expanded Renewable Energy Target (RET) scheme has been introduced by the Australian government which targeting 20% of Australia's electricity supply is generated from renewable sources by 2020. Consequently, this will drive large changes which will effect on behaviour and investment in Australia's market environment especially transmission use of system (TUoS) charging scheme. Hence, this paper is intended to explore the existing TUoS charging methodologies in the Australian National Electricity Market (NEM) to the development of renewable generation. There are some aspects related to the existing TUoS charging methodology which can be improved especially in the issues of transmission usage evaluation, percentage of transmission services allocation for the market users and also the transmission pricing methods. Therefore, in this paper, novel transmission pricing methodologies and mathematical formulation of the proposed approaches were introduced. There are two proposed schemes for allocations of TUoS charges for the renewable energy which called Distribution Factors Enhanced Transmission Pricing (DFETP) capacity-based method and DFETP energy-based method. Both methods were tested on the 59-bus system of the South East Australian power system in order to determine which approach provides a better TUoS charges allocation scheme.