Snowy Hydro 2.0 – What’s the deal with Pumped Hydro Energy Storage?

21.12.17 By

Today the feasibility study for the the much talked about Snowy Hydro 2.0 project was released. The project, first announced in March 2017, involves a $3.8 – $4.5 billion expansion of the current Snowy Hydro scheme to store energy from the grid. This is called “pumped hydro energy storage”.

What exactly is pumped hydro energy storage?

Pumped hydro energy involves storing water in an upper reservoir which has been pumped from a lower reservoir. During periods of high electricity demand, power is generated by releasing the stored water through turbines. While during periods of low demand, the upper reservoir is recharged by using lower-cost electricity from the grid to pump the water back to the upper reservoir.

Image: Snowy Hydro Ltd

Pumped hydro energy storage is a technology that has existed for more than a century, with over 40 countries currently using this technology.

Topline Facts:

Snowy Hydro 2.0 is expected to:

Australia has three large-scale pumped hydro facilities all built between 1973 – 84:


Pumped hydro energy storage can potentially be built in a location where there are two reservoirs separated by significant height. It could be:

Like other electricity infrastructure, pumped hydro faces may be affected by extreme weather events. Dry spells and droughts can result in lower dam levels, limiting electricity generation capacity, and cause price volatility. For example, according to a report released this week by the NSW Chief Scientist & Engineer, “NSW’s alpine region is projected to experience higher temperatures, fewer colder nights, and lower rainfall in the near and far future. This could pose risks to the current Snowy Hydro as well as reserves for Snowy 2.0.”


Image: Snowy Hydro Ltd

Pumped hydro can store energy from fossil fuel energy sources or from renewable sources. So does energy storage reduce electricity emissions?

It depends on the source of electricity or energy being stored. If it’s fossil fuels then no, as they are highly polluting. Whereas renewables (solar and wind) do not emit any emissions.

The Renewable Era

Energy storage will be a crucial technology as Australia and the rest of the world transitions to renewables, in the Renewable Era. And pumped hydro is going to figure significantly. However, the cost of storage and the size of storage amongst other factors will determine the mix over time. It could also take up to a decade to build a pumped hydro energy scheme.

While the Snowy Hydro 2.0 project may take nearly a decade to complete, there are numerous examples of renewable energy and storage projects already coming online around the country. Projects such as South Australia’s world-leading battery paired with the Hornsdale Wind Farm and the Kidston project in North Queensland which combines up to 330MW of solar power with pumped hydro energy storage utilising a former gold mine.

Pumped hydro storage in Kidston, QLD. Image: Townsville Bulletin

Potential benefits for tackling climate change

Energy storage technologies like battery storage and pumped hydro (but also heat storage in solar thermal plants, flywheels, fuel cells and compressed air) are all complementary technologies which can enable increased amounts of wind and solar power, because it allows excess power from the grid to be stored at times of high wind and sun, and used later when needed.

Storage, including pumped hydro is critical to tackling climate change and storing renewables. The critical issue with Turnbull’s idea is that he is proposing a storage solution but has not accompanied it with a generation policy. At this stage energy being stored would be from polluting coal fired generation. For the project to be valuable it must be accompanied by a policy to grow Australia’s clean energy resources.

Can pumped hydro projects like Snowy Hydro 2.0 cut pollution?

Only if pumped hydro energy storage is connected to renewables, and if it’s backed by a lot more wind and solar investment. Otherwise it’s actually far worse for emissions, if the energy used to pump the energy uphill comes from fossil fuels.

The Climate Council welcomes investment into pumped-hydro, but it must be accompanied by a national plan to transition from fossil fuel generation to renewables.

Planning & environmental impacts

While the Federal Government may have given its go-ahead to the Snowy Hydro 2.0 project to proceed based on today’s feasibility study, Snowy Hydro 2.0 is yet to receive planning and environmental approvals from the New South Wales and Federal Government (given the project is located within Kosciuszko National Park). The feasibility study anticipates the project being up and running in 2024 – following environmental approvals and construction. A final investment decision will be made in 2018.

Transitioning to renewable energy

Large-scale energy storage, like the Snowy Hydro 2.0 scheme, can assist with the transition to a renewable-powered grid. Energy storage technologies can store excess wind and solar power for use later when needed, providing 24/7 renewable power. However, energy storage projects will only cut pollution if they are backed by increased investment in solar and wind. Otherwise, energy storage can be far worse for emissions, if the energy used to pump the energy uphill comes from a largely fossil fuel powered grid (like NSW).

The Climate Council welcomes investment into pumped-hydro, but it must be accompanied by a national plan to transition from fossil fuel generation to renewable energy.