CSIRO–GTI partnership to develop supercritical CO2 plant

A Joint Industry Program to develop a supercritical CO₂ (sCO₂) power plant has been agreed by CSIRO and US-based GTI, a leader in the development and deployment of technology solutions to address energy and environmental challenges. The power plant could assist mining companies to reach large renewable energy targets.

sCO₂ turbines offer an autonomous, high-efficiency power cycle that doesn’t rely on steam. This makes such turbines an ideal candidate for power generation in off-grid mining and remote operations, as it allows them to use renewable energy more efficiently to power their operations for longer periods of time.

“While most power plants use steam to produce electricity, sCO₂ power plants use recirculating high-temperature CO₂ instead,” CSIRO Research Director Energy Technologies Dr David Harris said.

“The advantage is that sCO₂ is a higher density working fluid, which means sCO₂ power plants can be smaller, more efficient and not reliant on water for steam.”

Supercritical CO₂ cycles can also operate using a wide range of heat sources.

“Their widespread implementation could be a game changer for power generation applications in Australia,” Dr Harris said.

“With many mining companies committing to large renewable energy targets, the use of sCO₂ power could be the transformational technology that they are looking for.”

CSIRO’s involvement in the partnership will improve understanding of how sCO₂ power plants can enable lower- and zero-emission technology solutions, and how those plants might be used in remote mining and community locations as a low-cost alternative to diesel fuel power generation.

Of particular interest is how concentrated solar thermal (CST) technologies could be used to provide renewable energy for these sCO₂ power plants.

CST technologies capture and store heat, which make it an ideal solution. The Australian Solar Thermal Research Institute (ASTRI) which is a consortium of CSIRO and six Australian universities, is leading efforts in this area.

“The use of thermal energy storage (TES) to provide the heat to run these turbines is a critical enabler for renewable energy solutions,” ASTRI Chief Technical Officer Wes Stein said.

CSIRO is working with Graphite Energy, an innovative Australian TES company, on the use of portable and scalable TES units that can be used to store heat to run a sCO₂ power plant.

“The use of sCO₂ power blocks with our TES units will allow us to deliver the lowest-cost renewable energy solution currently available in the Australian market,” Graphite Energy CEO Peter Lemmich said.

The STEP Project demonstration plant has been built in San Antonio, Texas, at Southwest Research Institute (SwRI), and equipment installation is underway. It is expected to be operational in mid-2021.

For more information, visit STEP demo.

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