Becoming the Battery of the Nation

Strathgordon Power Station

Australia’s energy future is one of the hot topics right now with all sides of politics weighing in to the debate. Tasmania is uniquely placed to help lead Australia through its energy challenges.

By Steve Davy, CEO Hydro Tasmania

As Australia’s largest generator of renewable energy, Hydro Tasmania can play a significant role in identifying and delivering solutions that will support the country’s future energy needs.

Prime Minister Malcolm Turnbull and Tasmanian Premier Will Hodgman recently announced support for feasibility studies into boosting Tasmania’s clean energy capacity and making a greater contribution to the National Electricity Market (NEM).

In making the announcement, the Prime Minister said that, in an age of distributed, variable renewable power, Tasmania’s capacity to contribute not just to the energy security of Tasmania but the energy security of Australia was greatly enhanced and Tasmania could become a ‘battery’ for Australia.

This concept is particularly timely, because large storage devices like batteries and pumped hydro storage will become much more important as Australia seeks to transition to low-or-no-emissions energy sources, including solar and wind.

Energy sources like wind and solar only supply electricity when the wind blows or the sun shines – and are therefore known as “intermittent”. That’s fine when we have coal and gas to supply power at other times. But as older sources close, the market needs reliable ways to supply customers and industry.

Our island offers the necessary experience, skill, and renewable energy platform to take a leadership role in setting up a blueprint for how Tasmania’s renewable resources are developed over the coming decades, to support Australia’s transition to a low-emissions economy.

A blueprint for a renewable future

Tasmania currently provides about five per cent of Australia’s energy and more than 40 per cent of its renewable energy.

Hydro Tasmania is Australia’s largest generator of renewable energy and generates more than one third of renewable energy traded in the NEM.

Becoming a ‘battery of the nation’ is about significantly increasing that contribution through increasing Tasmania’s interconnection, boosting our hydropower system (including with pumped hydro storage), and further developing the state’s world-class wind power.

So, let me explain more about boosting Tasmania’s clean energy capacity and the work we are doing under Battery of the Nation

The Future State NEM Analysis: This is about building and testing models of a future Tasmanian energy landscape including energy storage, generation, demand response and transmission investment and looking at what expanded role Tasmania could play in a future NEM.

Pumped hydro storage assessment: We are completing an extensive assessment process across Tasmania to shortlist key regions and specific potential pumped hydro sites to take to the next stage of study. Our early assessment has shown significant potential in the state that could deliver up to 2500MW of generation capacity, nearly double what we have now.

Hydro system augmentation and improvement:We are investigating ways we can improve and optimise our existing hydropower generation. These projects are the Tarraleah Power Scheme (one of our older assets) and Gordon Power Station (our largest power station).

ARENA is supporting this work with funding under its Advancing Renewables Program.

As well as those proposals, Tasmania has many prospective wind farm sites, and our state is already considering more interconnection with Victoria. Tasmania currently has on-island wind power capacity of 308MW, and the introduction of pumped hydro storage could make wind farm development significantly more attractive.

Why is everyone talking about ‘batteries’?

During windy and sunny times, wind and solar may generate more electricity than is immediately needed, but that surplus power could be stored for later use. That’s why energy storage is becoming crucial. Energy storage systems also help balance energy from variable sources.

A battery in the electricity network is like a rechargeable battery at home. It’s good at supplying a lot of power quickly for a few hours. But storing enough energy to meet demand for several days or weeks would require an enormous number of batteries.

So when it comes to clean energy storage on a very big scale (we are talking about enough energy to meet demand for days or weeks), the biggest excitement is about pumped hydro storage.

Here’s how it works…

Conventional hydropower systems collect water in a lake or reservoir on higher ground. The water is run downhill to spin a turbine in the station below, generating electricity.

Pumped hydro storage systems have an upper reservoir and a lower reservoir. The water is stored in an upper reservoir and run through a turbine to a lower reservoir when electricity is needed – such as when the sun is not shining or the wind is not blowing.

The water can then be pumped back uphill when there is excess electricity in the system (which often happens with wind and solar).

Since connecting to the NEM via Basslink in 2006, Tasmania’s flexible hydropower system has already acted as a giant 500 megawatt battery for Australia, because of our water in storage. Tasmania’s energy can be exported to the NEM during times of peak demand. So while pumped hydro storage may form part of an exciting future, the foundations of Tasmania’s energy storage evolution are already in place.

And with the exciting Battery of the Nation initiative, Tasmania would become a large, flexible renewable energy supplier for the nation, providing clean power when customers need it.