Summary
The Battery of the Nation initiative is investigating and developing a pathway of future development opportunities for Tasmania to make a greater contribution to the National Energy Market (NEM). With the support of ARENA funding, Hydro Tasmania have conducted two pre-feasibility studies on the Tarraleah and Gordon hydro-electric power schemes exploring how each may be redeveloped for the future NEM.
The Tarraleah scheme located in the Upper Derwent River in Tasmania commenced generation in 1938 and continued to be developed in a number of stages to 1966. The Tarraleah Scheme currently generates around 634 GWh per year of largely base load energy, providing around 6.5% of Hydro Tasmania’s annual power generation. The analysis found that an option to expand the capacity of the Tarraleah scheme to 220MW and increase its flexibility in operation was potentially feasible.
As part of this project Hydro Tasmania also conducted a pre-feasibility analysis into how the Gordon hydro-electric power scheme may be redeveloped for the future NEM. The report found that a solution to more efficiently generate power from the environmental water flow released to the Gordon River using a smaller turbine designed for these flows is technically and commercially feasible. However, the project was prioritised against other business capital expenditure needs and will not be proceeding to implementation at this stage.
Learn more
How the project works
The Tarraleah pre-feasibility study compared redevelopment options against continuing to maintain the existing Scheme. Six redevelopment options were considered with the study concluding that the capacity-optimised redevelopment would provide an asset that is best placed to support a future electricity market with higher levels of variable renewable generation.
The capacity-optimised redevelopment involves more than doubling the existing scheme installed capacity to around 220MW and the development of additional intermediate storage capacity of 20 hours. This option will enable the Tarraleah scheme to move from being a stable baseload profiled generator to a generator with the ability to deliver incremental capacity as required by the market and allow balancing of variable renewable energy output.
Benefit
Work undertaken by HydroTas under its future NEM scenarios as part of the larger Battery of the Nation programme has identified a number of opportunities and challenges for Tasmania and its hydropower assets. One key opportunity is the superior wind resource conditions that exist in Tasmania and the fact that it is generally available at different times to wind resources in other states. The challenge is that to manage and balance this supply along with other variable renewable energy, a flexible storage system is required.
The broader Tasmanian hydro system has the potential to be structured and configured as a natural storage system that can be utilised to act as a flexible generator as renewable energy supply is increased across Tasmania and Australia.
Note: ARENA funding provided and total project value represents Tarraleah and Gordon projects.