Mountainous terrain with a large river running through a valley

How can a dam be a battery?

24 August 2018

Any water in a Hydro Tasmania dam is potential energy. We collect water in our dams then run it downhill to spin turbines creating energy. All that water sitting in our dams is like a big pool of electricity waiting for when it’s needed.

It’s completely renewable, clean, and for more than 100 years that’s how we’ve been able to keep the lights on in Tasmania. At the same time Australia more broadly has a big challenge ahead with its energy supply.

Almost three-quarters of our nation’s energy comes from coal, which will decrease in coming decades. We’ll need huge amounts of new energy generation to replace it, and renewables such as wind and solar are the cleanest and cheapest option.

This presents another challenge. Wind and solar power are intermittent. We can only produce wind energy when the wind is blowing and we can only produce solar energy when it’s sunny.

That's where Tasmania can help...

Through the Battery of the Nation initiative, we are looking at the potential to double Tasmania’s electricity generating capacity to 5,000 megawatts, by changing the way we use our existing hydropower system and adding pumped hydro storage.

Doubling our clean electricity generating capacity means guaranteed supply and lower prices for Tasmanians. It would also give us plenty of surplus energy to support Australia in its time of need.

We’re looking at building up to 2,500 megawatts of pumped hydro storage in Tasmania.

Think of it like a big battery. A battery stores potential energy so it can be used when it’s needed. In this way our dams are like huge batteries filled with water ready to be converted into energy.

At the moment, our dams are ‘recharged’ when it rains but we’re working on a new method called pumped storage hydro, which will recharge them without needing extra water. 


What is pumped hydro storage?

Infographic showing how pumped hydro worksTraditionally with hydroelectric power plants, once the water has been run downhill to turn the turbines it flows out to sea; pumped hydro lets us pump that water back up hill, to re-use for power generation again and again.

Of course, that pumping consumes electricity in itself. That’s where wind and solar power come in.

Pumped hydro, wind and solar work together like a giant renewable battery providing a stable, reliable and flexible clean energy system. Tasmania has lots of steep hills that were perfect for building hydro over the past century, and are ideal for developing pumped hydro today.

By adding pumped hydro to one of Australia’s big hydropower systems, we can build it quicker and cheaper compared to other places, even when you add in the cost of more interconnection to get our energy to where it’s needed interstate.

How do we make it happen?

We can do all this by building on our existing hydro sites protecting the mountains, lakes and waterways that we all love. We can do all this without building any new dams on rivers. We can do it without going anywhere near the precious Wilderness World Heritage Area that’s so special to Tasmanians.

For more than a century, we’ve been powering generations, creating power for people. We’re Australia’s largest generator of renewable energy, largest water manager and champions for a sustainable future.

Now, Tasmania can help lead the way again to benefit the whole country.

The Battery of the Nation initiative stands out as the viable, affordable solution to Australia’s growing energy challenge. Together we can deliver a future that’s clean, secure, reliable and prosperous.



Kicking diesel (and the injectors) off the islands >

Historically the communities on Flinders and King Island have relied on diesel generators to keep the lights on, but that has changed thanks to our hybrid energy solutions.

Aerial view of Cluny dam and power station

Cluny gets a little work done >

No not that Clooney. Our Cluny is about 30m tall, largely made of concrete and surprisingly about six years younger. Clearly, power stations deteriorate at a faster rate than Hollywood icons (arguably, they work a little harder), and the ‘work done’ here is closer to reconstructive surgery than your average aging actor face lift.


Engineering diversity >

Nurturing a culture of inclusion where diverse views and experiences are embraced and every person is valued and respected is one of our major objectives at Hydro Tasmania. That’s why we’re so proud to be one of two sponsors for Engineers Australia’s diversity in engineering scholarship for women.