When Finland recently unveiled the world’s first “sand battery”, there was speculation that Australian manufacturers would soon be releasing their own versions as they sought to burn less gas.
Key points:
- Australia’s first commercial thermal energy storage system to be installed later this year
- It will run on renewable electricity and help a pet food factory reduce its gas use, saving money and reducing emissions.
- Experts say similar systems will be rolled out across the country in the coming years
Now a pet food factory in Wodonga has announced it is doing just that.
The Mars Petcare facility, one of the nation’s largest pet food manufacturers, will take delivery of a “graphite battery” later this year as part of a trial to reduce emissions and ultimately save money.
From the outside, the orange container won’t look like much, but experts say the installation of the system is an important moment in the country’s clean energy transition, and these thermal energy storage facilities (TES ) will become a common sight over the next decade.
“It will be the first major commercial application of thermal energy storage to displace gas in Australia, so it’s a big deal,” said Dominic Zaal, director of the Australian Solar Thermal Research Institute (ASTRI), which is funded through Renewable Energy Australia. Agency (ARENA).
“It will be the first of many. In 10 years this will be widespread.”
So how does it work and what can it be used for?
Water in, steam out
Like the Finnish sand battery, the Wodonga TES system buys renewable electricity from the grid when it’s cheaper and turns it into heat using resistive heating (like an electric bar heater).
This heat is then stored in the graphite blocks at temperatures of up to 900C.
The modular design can be expanded. A single container has a capacity of about 3 megawatt-hours of thermal energy, which is equivalent to the amount of electrical energy stored by a large chemical battery in the neighborhood.
In practice, the battery is designed to charge and discharge at the same time, which means that over the course of a day it can process up to 8MWh of thermal energy.
When heat is needed, the water passes through pipes inside the sacrat and becomes high-pressure steam, at temperatures of 150-250C.
This heat is used wherever it is needed. In the case of the Wodonga factory, it will cook pet food.
The Wodonga factory is one of the largest pet food manufacturing sites in Australia. (Provided by: Mars Petcare)
The clean energy system will reduce the factory’s gas consumption by 20 percent, said Paul Matuschka, its chief sustainability officer.
The system is expected to be operational early next year and more batteries may be installed.
“We have a metric to be 100 percent renewable from direct operations in 2040,” Matuschka said.
The struggle to lower the gas
About 16 percent of Australia’s emissions are from burning gas in industry for processes that need high temperatures (anything above 100C).
Reducing these emissions requires more than installing solar panels and batteries, as electricity alone cannot generate high enough temperatures.
Heat pumps (the same technology used in reverse cycle air conditioners), which can run on renewable energy, have a maximum of around 100ºC.
TES is seen by many as the solution to this problem.
Mars Petcare Wodonga is a case in point: gas accounts for three-quarters of its energy consumption.
“More than 90 percent of natural gas use is used for cooking,” Matuschka said.
Without TES, the factory cannot lower the gas, he said.
“We are looking at thermal energy storage as a critical component to help us get to 100% net zero direct operations.”
Other major manufacturers investigating thermal storage
Although the Wodonga project has been in the works for more than two years, interest in TES has followed the recent rise in gas prices.
Wholesale gas prices have more than doubled since last year and are expected to remain high through 2023.
The Wodonga TES system is being built by an Australian company, Graphite Energy, based at Lake Cargelligo in central NSW.
Australian company 1414 is also developing TES systems, using silicon instead of graphite or sand. (Supplied: 1414)
It has seen a surge in demand in recent months, CEO Peter Lemmich said.
“Now that we’ve seen these price increases, there’s obviously a lot of interest from people,” he said.
The price hike, he said, has “eliminated the green premium” for TES.
“So going green is no longer a cost charge for the business.”
ASTRI’s Dominic Zaal said he is currently advising some of the country’s largest food and paper manufacturers on TES systems and off-gassing.
“We’ve had interest for a good year or two, but in the last three months, since the Russia trip to Ukraine … the imperative has been significant.”
“I have at least 10 fairly large companies that are interested in this technology.”
The Wodonga trial is being watched closely
The time it took for TES units to pay for themselves through gas savings depended on where a utility got its electricity, Zaal said.
If they’re buying off the grid, it might take 10 years, but if they’re generating their own, it could take up to five, he said.
“These systems are 30-year systems. Once you pay for it, it’s pretty much free,” he said.
Mars Petcare had calculated a payback period of 10 to 12 years, Matushcka said.
Other companies were watching the Wodonga factory trial closely, Graphite Energy’s Peter Lemmich said.
“Everybody we talk to knows this project is going ahead and they’re all sitting, let’s look at it.
“And if this does what you said it would do, then, you know, we want to talk.”