The concept of a global electricity network has been developed to take into account the different time zones, seasons, load patterns and the intermittency of the growing levels of renewable generation. Using a time horizon of 2050, Working Group C1.35 has addressed the challenges, benefits and issues of the uneven distribution of energy sources across the world. It is postulated that the use of high capacity long transmission lines would enable much greater use of renewables and address the key challenge of intermittency. While there are no Australian members on the working group, it is considered this should be of broad interest as the proposed grid includes an interconnection with Australia and it addresses some of the issues that have been raised in relation to the interconnection of the West and East coast systems in Australia. The WG has recently produced Technical Brochure 775.
The Technical Brochure necessarily takes a high-level assessment of the benefits of globally interconnecting all the major regions of the world. Only one interconnection node per region is identified and priority is given to the identification of major transmission corridors that are higher than 2GW. Only one scenario was considered, however, sensitivity analysis was carried out to assess the impact of varying parameters.
A reference case for 2050 without the interconnections produces an average cost of 54€/MWh for generation with a renewable energy share of 53% and CO2 emissions of 850 Mt/yr. The use of interconnections leads to an average cost of 48€/MWhr with a renewable energy share of 76% and CO2 emissions of 343 Mt/yr. This initial work shows it is possible that these interconnections could deliver considerable environmental benefits.
The study seeks to balance the costs of the interconnections depending on their unit costs, and the benefits of mutualising the load curves of different zones and access to renewable generation with better capacity factors. It is notable that major installations of wind in Central Asia with very good capacity factors are a significant factor in the improvements from the reference case. Other benefits come from an excess of production in North America, which can be exported to Asia and Europe through Russia.
The additional cost of the infrastructure is largely compensated by the reduced generation costs where wind and solar replace gas fired generation.
The results of this study depend on the assumptions selected and the parameters used for the simulations. Sensitivity analysis shows good resilience of the results as a whole and, as a result of this, a follow up Working Group, C1.44, has been initiated to challenge the present results and examine the potential further benefits that may come from the implementation of alternative solutions for flexibility with more storage and demand side facilities within a region.
The Technical Brochure is available free to members and €260 to non members through e-cigre.