Green steam and thermal storage startup reboots pilot plant after “tough lesson”

New South Wales energy storage hopeful MGA Thermal is on the hunt for “significant” new capital, after the successful commissioning of its 5 megawatt hour (MWh) pilot plant in Tomago.

The milestone, announced on Tuesday, marks the second time around for MGA Thermal, after a “dangerous heat build-up” derailed a first attempt at commissioning the demonstration plant back in October 2023.

But after 18 months of investigation and reconfiguring, the project is back on track. 

The company’s energy storage technology uses miscibility gap alloys (MGA), a material invented and perfected by cofounders Erich Kisi and Alexander Post over a decade at the University of Newcastle. 

A miscibility gap is an area in a mixture or alloy where the different components don’t mix well and instead separate into two or more regions with different compositions.

It works by stacking the blocks of MGA into insulated tanks to store huge amounts of energy, with wasted industrial process heat being a big initial target.

The company’s current kiln can deliver 100 blocks every 24 hours.

But with a 5MWh project needing 3712 blocks, MGA Thermal must scale up to handle the hundreds of megawatt hour projects it one day hopes to deliver, Post says.

“The next step will be a relatively significant capital raise in the near future,” he told Renew Economy.

“We’ve been fortunate with support from our lead investor which is [CSIRO commercialisation fund] Main Sequence Ventures, as well as follow-on investments from a number of our smaller investors, as well as ARENA and the federal government.”

The next step is a commercial pilot in the 5-10MWh range, but Post says they have feasibility studies under way for a 300MWh facility and have completed one for Chevron that it started in December.

Startup mentality meet deep tech

The “dangerous heat build up” speed bump in 2023 now has a backstory after 18 months of investigation and reconfiguring.

MGA Thermal’s kiln broke, leaving three quarters of the blocks needed for the pilot only partly fired.

So the engineers wondered whether they could use the heat inside the unit to finish baking the blocks. They reconfigured the pilot to allow this and then watched for what would happen.

“That decision was a big mistake in hindsight. One of the root learnings was ‘do not conduct this manufacturing process in situ’,” Post says.

The problem was that the MGA material gives up a small amount of heat during the baking process. It was a detail they’d missed when the blocks were spread out in MGA Thermal’s uninsulated, industrial-sized kiln.

But that final detail became very apparent when three of the four modules, each containing 928 blocks, were packed into an insulated space.

“The heat given off was comparable to the amount of heat that the blocks will naturally undergo when charge and discharge in operation, but not in a controlled manner,” Post says.

“That’s what happens in deep tech, you come across new things. It was a tough lesson to learn but this is the reason we piloted in-house, to figure these things out for ourselves.”

The upside is that one of the four modules that make up the 5MWh pilot did contain fully baked blocks, and this one worked perfectly. 

The incident caused the company to grow up fast from a see-what-happens science startup to a more mature venture, as it launched into commercialisation.

Post says they now have “rigorous” testing measures in place before trying new ideas on a $3 million machine, as well as failsafes to prevent overheating.

They’ve also changed how they make the top-secret material used in the blocks, with that slight chemistry change enough to mitigate future problems.

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