Thermal battery for when the sun don't shine

UNIVERSITY researchers believe the thermal battery they are developing will be a key to solar power systems being able to discharge electricity at night and be a boon for mining operations.
Thermal battery for when the sun don't shine Thermal battery for when the sun don't shine Thermal battery for when the sun don't shine Thermal battery for when the sun don't shine Thermal battery for when the sun don't shine

Thermal battery aims to solve the problems solar systems have: what happens when the sun goes down?

The project, led by Curtin University School of Electrical Engineering, Computing and Mathematical Sciences professor Craig Buckley, includes collaboration with international renewable energy companies United Sun Systems and ITP Thermal.

It aims to develop technology to integrate thermochemical energy storage via a thermal battery into a dish-Stirling system.

A dish-Stirling system can provide up to 46 kilowatts of power and is ideal for powering remote energy intensive industries such as mine sites due to it providing power on demand.

Several dishes can be deployed depending on the power requirements on site.

Buckley said the thermal battery was part of the Concentrated Solar Power system being developed by United Sun Systems, which required a battery to store and release energy to enable non-stop solar power generation.

"Storage has long been a stumbling point for renewable energy but our prototype thermal battery is able to store and, as required, release solar energy without reliance on sunlight at all times," he said.

"The battery uses a high temperature metal hybride or metal carbonate as the heat storage medium and a low temperature gas storage vessel for storing the hydrogen or carbon dioxide.

"At night, and at times of cloud cover, hydrogen or carbon dioxide is released from the gas storage vessel and absorbed by the higher temperature metal to form a metal hybride-metal carbonate, which produces heat use to generate electricity."

Miners have contemplated such technologies before.

Anglogold Ashanti and Independence Group once considered a solar-thermal power system for their Tropicana gold operation in Western Australia's Eastern Goldfields.
However, the then government removed a renewable energy subsidy it had in place at the time. Without the subsidy the technology risk was considered too great and the plan was shelved.

That system would have involved a solar collector arrangement that would use heat energy to break down ammonium into nitrogen and hydrogen atoms. When the sun went down the ammonium would be allowed to reform and the energy released from that would provide power.

Another alternative is to use a solar collector to melt salt, while also heating water to steam to turn turbines and generate electricity. When the sun goes down the water is directed through pipes in the molten salt, using the heat from that to generate the steam.

Curtin University deputy vice-chancellor research professor Chris Moran said the project aimed to develop a solar power system that produced electricity 24 hours a day, seven days a week and was commercially viable for industry.

The research project Thermal Battery Development for Concentrated Solar Power Systems was awarded $1 million by the federal government's Global Innovation Linkages Program.