Developed at the University of South Australia in Adelaide, the method involves using low cost renewable energy such as wind or solar PV to power electrical elements that heat rocks in a similar way to a sauna.
The element and rocks are packed inside a stainless steel tank and heat air pushed through the tank with an ambient fan. The temperature of the exiting air can be simply adjusted between 200C and 700C by changing the fan speed.
The successful testing of a 35kWh thermal prototype system has led to the development of a final 1.5MWh thermal prototype. The second prototype is expected to be finished by the end of the year and will form the basis of the technology’s first commercial product. The modular technology is fully scalable, allowing multiple systems to be built into shipping container-sized units.
Research indicates about 20 per cent of global fossil fuel emissions are currently produced by industry, largely through burning natural gas to create heat for various manufacturing processes.
Rhys Jacob, from the University of South Australia’s Barbara Hardy Institute, said the system developed by his team not only had environmental benefits but offered potential savings against increasingly unstable gas prices and was more cost-effective storage than battery technology.
He said the 1.5MWh thermal prototype would be about 1.5m tall, 1m wide at its base and would likely be powered by a 250kWh solar PV system.
“We charge at 150kW electric and we discharge at 150kW thermal for 10 hours – the conversion from electrical to thermal is generally 1:1 with these types of heaters as the elements we use are about 98 per cent efficient,” Jacob said.
“It is all low cost because it is all made of readily available materials.
“One of the key elements of it is that it is easy – we’re just taking ambient air so we don’t have to worry about …