Storage remains the pain point in the renewables transition so it’s no surprise a cheap, clean and scalable energy storage technology invented by Australian scientists is attracting attention.

Researchers from the University of Newcastle have been developing the energy storage technology called “miscibility gap alloy” for nine years and are now scaling it up for commercial use under the MGA Thermal banner.

The stackable, brick-like invention relies on carefully contained phase change materials that store a huge amount of energy as heat.

In its current form it’s made up of two metals – aluminium and graphite – that behave in different ways when heated: one melts while the other stays solid.

The result is storage that has the desirable characteristics of a phase change system (high energy and constant temperature) that behave as a continuously solid, modular 20cm x 20cm x 16cm block.

Speaking to The Fifth Estate, cofounder and chief executive officer of the company, Professor Eric Kisi, says there were about seven different markets the company could have targeted first up, including heating buildings.

Then an opportunity arose that set the company on its scale up trajectory. Swedish energy company E25 Power contacted the company to supply its technology for a decommissioned coal fire power station to be converted to run off steam.

The contract was signed in September last year and since then the company has been going flat chat towards commercialisation, starting with a pilot manufacturing plant in Newcastle funded by a $495,000 grant from the federal Department of Industry, Innovation and Science.

For Kisi, the repurposing of existing power plant infrastructure into emission-free, grid firming storage is an attractive proposition, giving soon-to-be-decommissioned coal fire stations in Australia a second life and preventing job losses in those regions. 

The technology would work by storing energy in MGA blocks at peak renewable energy production times (when the sun is shining and the wind blowing) and when there’s lower supply, using them to heat water to create steam to run turbines and generators to produce electricity instead of burning coal to the same effect.

The main challenge holding back the clean energy transition at the moment, according to Kisi, is that without appropriate clean storage you need 700 per cent-plus renewable energy to cover that “one day in t10 years when its cloudy and the wind isn’t blowing anywhere”.

“Who is going to invest in all that capacity when it’s not doing anything for huge chunks of time?”

With the grid already experiencing periods of oversupply, Kisi says the technology could act as a third serious source of clean energy storage alongside batteries and hydro. While batteries have a super quick response time to rapid dips in supply, they are expensive, reliant on hard-to-come-by materials and difficult to scale. It’s no secret that the Tesla batteries in SA – the largest grid connected battery in the world – can match the power output of the recently closed Liddell Power Station for just seven minutes.

Hydro, by contrast, is capable of massive generation but it has ecological drawbacks and there’s only so many spots you can put them.

MGA technology is far cheaper than lithium batteries, with the cost of storage of $50 per kilowatt hour in the pilot setting (chances are it will get even lower) compared to lithium-ion batteries that cost around A$200 per kilowatt hour.

The problem with the new technology is that it’s slower to respond than batteries, taking around 15 minutes to start generating.

Kisi imagines that a combination of batteries, MGA/thermal storage and hydro would meet all clean storage needs, facilitating further renewables penetration.

A completely recyclable technology

It took a long time for researcher to find materials that are safe, effective, cheap and readily available. The team landed on graphite and aluminium, both fairly easy to source although there is some competition for graphite from battery manufacturing.

The projected life of each brick is decades and the materials can be easily separated to be made into new blocks or ground up to be used in something else entirely.

Easily transportable, the blocks can be easily relocated for alternative uses.

Scale up ambitions on track

As a professor in materials science at the university, Kisi was one of the founding members of the company, which was formally established in April 2019.

It’s now grown to a team of nine, which Kisi says is about the right size to deliver the pilot plant, to be situated somewhere in Newcastle.

Recently selected as part of EnergyLab’s 2020 Scaleup Program, Kisi says the next step in its scale up ambitions will likely be a pilot coal plant retrofit in Australia comparable to its work with the Swedish company.

He says that Covid hasn’t slowed its commercialisation program down much aside from some of the overseas work. It’s otherwise full steam ahead for the business (pardon the pun) with a Series A capital rise on the cards for early next year.

At this stage, the plan is to keep manufacturing within the company for the next couple of growth stages before potentially partnering with a manufacturer better placed to deliver “a few hundred thousand tonnes a year”.

“That’s when it’s getting pretty serious.”

Beyond large scale storage, the company is eyeing off several other applications, including in the built environment. Kisi can see the technology used on a building scale to store energy generated by rooftop solar to heat buildings at night.

“That would probably be the next market we aim for.”

One potential drawback would be the bespoke nature of implementation, with lots of technical intervention likely.

Other built environment applications could be using it process heat in industrial buildings for food processing and other manufacturing purposes. 

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  1. The main problem of thermal electricity storage is efficiency. Batteries and hydro are around 80% efficient. Thermal storage and steam generation is lucky to reach 40% – makes the economics much harder. Remember the Rankine cycle puts a limit on thermal power generation without very fancy machinery.

  2. what a great idea to use existing steam plants to generate electricity. If you couple that with solar thermal collectors that can heat the water to steam during the day for free you have a perfect solution!

  3. “Who is going to invest in all that capacity when it’s not doing anything for huge chunks of time?”

    Generate hydrogen for green steel making and export!