Recently, there has been significant media attention surrounding Mars Petcare and their installation of a “graphite battery”—a novel thermal energy storage system developed by the Australian company Graphite Energy.
But what exactly is a graphite battery?
What makes it innovative?
And when can we expect broader adoption?
What is a Graphite Battery?
A graphite battery in this context refers to a thermal energy storage system that utilizes graphite blocks to store heat—effectively functioning as a thermal battery. The system converts surplus electricity, typically from renewable sources, into heat and stores it in solid graphite for later use.
How It Works:
- Charging: Electricity (e.g., from solar or wind) is converted into heat using resistance heaters. This heat raises the temperature of the graphite blocks.
- Storage: The graphite blocks act as thermal reservoirs, retaining the heat for extended periods. The heat can be stored at temperatures as high as 900degC - that's hot!
- Discharging: When needed, water or another fluid is passed through the hot graphite, absorbing the stored heat and converting it into high-pressure steam or hot air for use in industrial or heating applications.
Applications
Industrial Heat Supply:
- At Mars Petcare, the system will be used to generate superheated steam (150–200°C) for food processing, reducing reliance on fossil fuels like natural gas.
Grid-Scale Energy Storage:
- Graphite-based systems can absorb excess renewable energy and dispatch it as thermal energy when demand rises, supporting grid stability.
District Heating:
- Stored thermal energy can be distributed to residential and commercial buildings, supporting decarbonized heating networks.
A Real-World Example: Mars Petcare & Graphite Energy
Mars Petcare is leading by example with its investment in Graphite Energy’s technology, using thermal energy storage to power its operations and reduce carbon emissions. The system allows the company to displace natural gas consumption, demonstrating how thermal storage can be a practical solution for industrial decarbonization.
According to Mars, the system is expected to have a payback period of 10–12 years—a strong case for financially sustainable innovation.
Other Innovators: MGA Thermal
Another Australian company, MGA Thermal, is also exploring thermal energy storage. Their systems use graphite blocks combined with an aluminium alloy, offering long-duration and cost-effective storage solutions aimed at large-scale applications.
Key Benefits of Graphite Thermal Energy Storage
- Cost-Effective: Graphite is abundant and inexpensive, reducing overall system costs.
- High Efficiency: Graphite’s excellent thermal conductivity allows for efficient heat storage and transfer.
- Long-Duration Storage: Heat can be stored for hours or even days, making it suitable for load shifting and grid balancing.
- Scalable: Systems can be scaled to suit both small- and large-scale energy demands.
- Safe and Stable: Graphite is chemically stable and non-toxic, making it ideal for industrial use.
The Big Picture
The coverage of Mars Petcare's graphite battery by the ABC has drawn international attention to this emerging technology.
As the world transitions toward renewable energy, thermal energy storage using graphite offers a promising pathway for industries and utilities to store cheap, surplus electricity and repurpose it efficiently.
This is one to watch—a powerful, scalable solution for a decarbonized future.
At this point it's still a trial so it's early days, very exciting to see where it goes!