The Spill

For more than a century, Tasmania’s hydroelectricity assets have been generating clean, renewable energy by leveraging the state’s natural advantages in water. 

Hydro Tasmania is proud of our heritage as a responsible water manager, and of the social and economic advances the state has made since the turbines began spinning back in 1916. 

Now, as Australia moves to rapidly decarbonise the National Electricity Market by phasing out coal-fired generation, opportunities have emerged for Hydro Tasmania to play a vital role in the low-carbon energy systems of the future. 

And that means using Tasmania’s water resources in a smarter way. 

Like the national energy market itself, Hydro Tasmania is undergoing fundamental change.  

As more diverse sources of clean energy are built here in Tasmania and the mainland, the increased flexibility of generation means hydropower will no longer have to do all the heavy lifting. Taking the pressure off Tasmania’s water resources into the future is a win-win – we can use our precious water more selectively and build greater resilience to climate change impacts.  

In fact, Battery of the Nation won’t use any more water – we will use the same water in a much more valuable way. Hydropower infrastructure originally designed to provide baseload power will instead supply a premium on-demand energy product to the national grid, bringing significant economic benefit to Tasmania. 

Hydro Tasmania’s Battery of the Nation project – which relies on the proposed 1500 megawatt capacity undersea electricity interconnector Marinus Link between Tasmania and Victoria – will develop a pathway of future opportunities in hydropower system upgrades including adding pumped hydro. 

The benefits to the state are great – giving Tasmanians access to the lowest possible power prices, creating jobs, locking in energy security and bringing economic benefits to Tasmania.  

While low-cost wind and solar are doing the heavy lifting as the National Electricity Market transitions, both are reliant on favourable weather conditions. This is where Tasmania’s celebrated hydropower capacity comes into play, using existing huge reserves of stored energy to plug solar and wind’s reliability gap with on-demand, or “dispatchable”, electricity. 

The first plank in the Battery of the Nation proposal involves getting more out of Hydro Tasmania’s existing assets, particularly through the potential redevelopment of the iconic Tarraleah hydropower scheme, helping us get more energy from the same amount of water. 

The potential redevelopment of Tarraleah, plus the realisation of other efficiencies across Hydro Tasmania’s hydropower system, will pave the way for maximising the first of two 750MW Marinus Link cables. 

The second Marinus Link cable will trigger the delivery of a proposed pumped hydro project at Lake Cethana in Tasmania’s North-West. 

Pumped hydro is a flexible and sustainable technology that involves recycling water between a storage at a higher elevation, and another storage at a lower elevation. 

When the demand for electricity is high, or when other renewable sources are scarce, the water in the upper storage can be released to generate electricity.  

Water from the lower storage can then be pumped back to the upper storage when power in the market is at a lower cost – created by times of excess wind and solar generation. That energy would otherwise be wasted. 

Pumped hydro will allow Hydro Tasmania to generate power when it’s needed without the need for more water. 

We take our responsibilities as the country’s biggest water manager very seriously. Hydro Tasmania has a mature aquatic environment program and strong scientific understanding of the lakes, waterways and land we manage. After all, these are shared resources for the Tasmanian community to enjoy. 

We conduct regular assessments of both water and land management activities across the state’s six major hydropower catchments to ensure our operations are environmentally sustainable. 

Assessments consider social, environmental, and economic conditions and are made in consultation with a variety of stakeholders. 

Environmental considerations are integrated into decision-making at all levels at Hydro Tasmania, and all new developments are subject to approvals processes under environmental laws. 

Tasmania can make a significant contribution to the transformation of the National Electricity Market in coming years, bringing benefits to both Tasmania and Tasmanians. Hydro Tasmania is committed to doing so in an environmentally, socially and economically responsible way.