Energy storage is an increasingly important part of our electricity system as it allows us to ensure energy is always available even when the sun and wind are not. Pumped hydro is the most common and most mature form of this energy storage.
Dispatchable power can be added into the market to balance electricity supply and demand. Pumped hydro, including Snowy 2.0 and Battery of the Nation, can help us deliver a more reliable energy system, reducing the risk of blackouts and electricity price volatility.
How pumped hydro works
Pumped hydroelectricity schemes are a flexible way of managing our demand for electricity. In conventional hydroelectricity generation, water flows from a dam or reservoir where it has been stored and is then channelled through rotating turbines. These turbines then generate power.
Pumped hydro operates on the same principle except that two dams, one higher than the other, work in a cycle that pumps water into the upper reservoir during off-peak hours. Potential energy is then stored and generated when it’s needed.
For example, when prices are cheap but demand is low, water in the low reservoir is pumped to the higher reservoir until it is needed for generation.
When both prices and demand are high, the water is released back into the lower reservoir—gravity does much of the work, so this energy production is cheap and efficient.
Snowy 2.0 will expand the original Snowy Mountains Hydroelectric Scheme with an additional 2000 MW of electricity generation capacity and 350,000 MW hours of energy storage. Creating up to 5000 jobs and producing enough power for 500,000 homes, it will link the Tantangara and Talbingo reservoirs with a 27 km tunnel and a new power station that will be around 1 km underground.
Snowy 2.0 is critical to the future security and reliability of our energy system and will put downward pressure on electricity prices through providing much needed dispatchable generation capacity and energy storage, reducing our reliance on more expensive forms of generation.
Snowy 2.0 represents the largest energy storage project in the southern hemisphere and the largest renewable energy project in Australia.
The iconic Snowy scheme already plays a critical role in ensuring system stability at times of peak demand by providing more than 4000 MW of existing fast start dispatchable generation capacity. Snowy 2.0 will increase this capacity by 50% to 6100 MW. First power is expected from Snowy 2.0 in mid-2025.
Battery of the Nation and the Marinus Link Interconnector
Battery of the Nation
Battery of the Nation is a Hydro Tasmania initiative to expand Tasmania’s renewable electricity generation capacity to supply mainland Australia. The project includes hydropower system improvements and new pumped hydro opportunities.
The Australian Government has provided $65 million to the upgrade of the Tarraleah hydropower scheme, a key Battery of the Nation asset, through the Bilateral Energy and Emissions Reduction Agreement.
Marinus Link is the proposed second interconnector providing an additional 1500 MW of capacity between Tasmania and the mainland. It will take advantage of Tasmania’s extensive renewable energy resources.
On 19 October 2022, the Australian Government announced it would provide access to low-cost finance from Rewiring the Nation for Marinus Link and the associated North West Transmission Developments.
When constructed, Marinus Link will provide the National Electricity Market with over 500 MW of dispatchable generation, which, due to limited BassLink capacity, is currently unavailable. This would power up to 500,000 homes and help manage the impact of variable wind and solar generation, unplanned outages and extreme weather events.
The link will also enable expansion of Tasmania’s hydro capacity through Battery of the Nation. This will unlock additional renewable energy investment in the state. It is estimated that Marinus Link will contribute savings of up to 70 million tonnes of CO2 equivalent by 2050.
Marinus Link is expected to create up to 2800 direct and indirect jobs during construction and deliver up to $3.65 billion of economic stimulus to north-western Tasmania and regional Victoria.
Battery of the Nation Hydro Tasmania
Project Marinus ARENA and TasNetworks