Climate change policies worldwide lead to more and more renewable power integration into existing grids. Emission pricing schemes in different jurisdictions also accelerate this trend. Most of these policy changes and incentive allocations are targeting a subsidy for power generation. Generators located far away from a grid require a huge investment to build a long distance transmission line. Justification of these large investments, efficient transmission configurations and cost allocations are still a challenging issue for long distance renewable power transmission.
This thesis addresses the economic, regulatory and reliability aspects of the long distance transmission which will connect large scale renewable power to the Australian NEM (National Electricity Market) Grid. Given the large scale geothermal resources of the Cooper Basin area in the mid-land of Australia, a 500km line to South Australia and 1000km line to Queensland have been investigated.
This research proposes a network configuration for connecting remote renewable generators to the existing grid. The proposal suggests that every individual renewable generator in a remote location can be connected to a hub in the range of tens of kilometre line. The hub will be connected to a distant grid through a high capacity transmission line. This transmission configuration is termed as ‘hub approach’, which is based on Scale Efficient Network Extension (SENE) proposition of the Australian Energy Market Commission (AEMC). Unfortunately the SENE proposition was later discarded. This method offers an efficient and low-cost connection arrangement, which can reduce the risk of stranding asset and free rider problem.
A net market benefit framework is developed which considers explicit ‘emission benefit’ of large scale remote renewable generation. In addition to the benefit of producers, consumers and merchandisers, the benefit of emission price and Large Scale Renewable Energy Target (LRET) payment have been incorporated in the net market benefit scheme, which justifies the value of renewable power compared to conventional generations. The consideration of emission benefit in the market model has made renewable energy projects more competitive in the market.
While the net market benefit has identified beneficiaries in the market, a game theoretic approach is proposed to allocate network usage cost among market participants. The Shapley Value approach allocates transmission costs among transmission network users in proportion to the benefit they obtain from the network. The proposed Shapley Value based network pricing methodology and cost allocation is proved to be equitable and more favourable to enhance large scale remote renewable generation.
In the analysis of net market benefit of large scale remote renewable power integration to the existing grid, the impact of uncertainty modelling have been performed through a Markov Chain Monte Carlo based approach, namely Metropolis-Hastings (M-H) sampling algorithm. The uncertainty of geothermal generation cost, wind fluctuations and load demand has been investigated on system economics, reliability and congestion.
Impacts of the Australian emission pricing scheme, namely Clean Energy Bill, 2011, have been modelled in this study. Emission cost has a very high influence on the market price of electricity and future generation portfolio. The investment trends are also affected due to the employment of the CO2 emission cost in an electricity market. Transmission technologies i.e. HVAC, HVDC, LCC (line commutated converter), VSC (voltage source converter) and Multi-terminal HVDC options have been investigated highlighting the economy and reliability.
A ranking procedure for different low emission generation technologies have been compared and presented in numerical and analytical results. The priority ranking has been calculated considering net market benefit and surpluses obtained by different market participants. Investigation of the priorities of producers, consumers, merchandisers and market operators regarding the candidate generation projects have been presented through the Multi-Attribute Decision Making (MADM) approach. A priority ranking procedure, namely TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) algorithm, has highlighted the preferences of market participants. This ranking procedure has identified the preferences of market participants, which have demonstrated the views of different stakeholders.
In the simulation studies, optimal power flow, reliability analysis and economic (cost-benefit) evaluation have been performed with commercial software platform of MATLAB/MATPOWER, CRUSE (Composite Reliability Using State Enumeration), and PSS/E®. Concepts are verified through the IEEE RTS (24 bus test system), Simplified South-East Australian (5 areas, 14 generators, 59 buses) test system, and Queensland power system network (1200 bus, 12,000MW). This study provides input to the system operator, market participants and potential investors to understand the network issues and market aspects due to Cooper Basin and some other possible large scale renewable power integration projects to the Australian NEM grid.