‘We are beating lithium in the long-term’: Allegro founder on microemulsion flow batteries

Allegro Energy is an Australia-based developer of water-based redox flow battery energy storage solutions. It recently completed Australia’s first locally manufactured microemulsion flow battery (MeFB), which is suited for long-duration energy storage (LDES).

In an exclusive interview with ESN Premium, Nann explains that the levelised storage cost is low compared to lithium-ion batteries; when factoring in the longevity of flow batteries and the company’s MeFB solution, it easily beats lithium, he claims.

Several processes are crucial to the technology, helping mitigate the battery’s degradation and making it cheaper to develop. At the core of this is using already abundant materials.

“We have made it our mantra to only touch commodity materials already on the market. That has several advantages. The first one is that our battery is not very expensive now, and we can scale quite easily. We can buy everything we need off the shelf,” Nann says.

In addition, Dr Nann explains that the technology is not very flammable, which contributes to the scalability of the company’s technology, particularly when considering its use for LDES applications.

Decreased flammability could also help mitigate fears surrounding battery safety risks. Indeed, in New South Wales, the state that Allegro calls home, the New South Wales Fire and Rescue Department deemed batteries the “fastest-growing fire risk to the state”, which helped prompt the government into introducing a Product Lifecycle Responsibility Act for batteries.

The inception of Allegro’s MeFB technology

Dr Nann, originally from Germany, has an academic background and explains that he first started researching the technology in 2005 with the release of a paper on microemulsions.

He moved to New Zealand to work at the Victoria University of Wellington in New Zealand. First, Dr Nann looked into artificial leaf technology before fully committing to developing energy storage solutions in 2010 when he left the country for its neighbour.

“At that time, I was working on artificial leaves, water splitting, solar cells, these types of things. Then I moved to Australia and realised there was such an abundance of renewable energy that I realised generating renewable energy was not the problem. The real problem is ensuring the lights don’t go out at night,” Dr Nann says.

“I took this opportunity and thought, right, if I must start my research again, I will concentrate entirely on storage now.”

But how does Allegro’s MEFB technology work, and what are its core components? The organisation’s mantra became creating a storage solution that uses abundant, readily available materials.

“The one constraint we gave ourselves was that we wouldn’t touch anything that is not scalable or sustainable. That meant we wouldn’t build the world’s best platinum-iridium gold battery,” Dr Nann jokes.

“We only used materials and considered those abundantly available, ensuring there are no supply constraints. This isn’t easy to achieve. We began exploring flow batteries, which are now our main product.”

Flow batteries have continued to be a central discussion point for energy storage in recent months.

Indeed, earlier this month at our publisher, Solar Media’s Energy Storage Summit Australia 2025, Carl Christiansen, associate director of business development & transactions for the Australian Renewable Energy Agency (ARENA), highlighted the rise of flow batteries, particularly vanadium, in the country.

‘We tried it, and we were blown away’

While exploring the use of flow batteries, Dr Nann experienced what he claims to be a “dilemma” regarding the technology’s limitations.

“I saw this dilemma: If you have an aqueous flow battery, like vanadium or all-iron, you are very limited by the water because in all of these batteries, when you charge them, you split water, you electrolyse the water,” Dr Nann explains.

“Also, due to the use of water, if you look at the all-iron system, for example, you create rust when you charge the battery, and with that comes lots and lots of problems. “

Instead, Dr Nann and his team looked towards organic batteries, which he says perform “really, really well” and that you can build a “wonderful battery”. However, much like platinum and gold, commercially, it is difficult as it is “way too expensive” and flammable.

From this, Dr Nann turned his attention to microemulsion, which he describes as “basically water, oil and dishwashing liquid.”

“If you get the ratios right, it stays homogeneous and mixed. My idea was to mix the two and prevent some of the problems that come with water, and we could have a wider range,” Dr Nann says.

“We then tried it, and we were blown away. These microemulsion electrolytes had fabulous properties. When you mix two things, you usually get the worst out of both worlds. But in this case, we got the best out of both worlds. That was the big breakthrough.”

Allegro’s eyes turn towards Origin Energy MeFB trial

Following this significant breakthrough, Dr Nann moved to the University of Newcastle in New South Wales, where he continued his research. Since then, he founded Allegro Energy and filed a patent for the technology, which has been granted in at least all the major jurisdictions.

Origin Energy, Melt Ventures, and Impact Ventures also back the developer. Its technology will soon debut at Origin’s Eraring Power Station, a black coal-fired plant in New South Wales. The plant is also home to one of the country’s most extensive battery energy storage system (BESS) developments.

Origin Energy, a leading Australian utility company, acquired a 5% equity interest in Newcastle-based Allegro in 2023, citing the technology as “very promising.” Under the agreement, the utility would house a 100kW/800kWh MeFB trial. This could then be scaled to reach 5MW/60MWh in the future.

Dr Nann, while, obviously, not speaking on behalf of Origin Energy, says that Origin will connect the MeFB battery to its virtual power plant (VPP), which will be grid-connected.

“It’s almost a bit of an overkill because the battery is not that big. But what will be interesting for us is that it will be in a real-world environment, and they [Origin Energy] will use our battery for whatever they want, should it be Frequency Control Ancillary Services (FCAS), to arbitrage,” Dr Nann says.

“That is good because it gives us a proof point. It will be in an environment where a bigger battery wouldn’t be that different.”

After this trial, Allegro and Dr Nann intend to scale up the company and the technology to help support the energy transition in Australia.

“In our business plan, we plan to scale 10x for the next five years every year, and then we will be at the gigawatt-scale, and Origin is part of that journey. The next steps for us are more pilots or smaller batteries, say, five or so, up to 10MW, and then we scale rapidly.”

Dr Nann explains that Australia is the perfect location to explore energy storage technologies, calling it a “great market,” and ahead of Germany, for example.

“My home country is probably two or three years behind us,” Dr Nann says.

‘Do something that’s meeting a need right now’

Dr Nann concludes by expressing his desire to support other academics in commercialising and investing in new technology to support current needs. He states that the biggest advice he can provide for other prospective academia is to “jump off the cliff.”

“Do something meeting a need right now, where there’s a need in the market. And remember, you have to jump off the cliff at some point. If you wait until you’re finished or until the product is perfect, you will never do it,” Dr Nann explains.

“I realised that the successful ones [inventors] just did it. They did not wait for the stars to align. They just did it. This is something that I would say if an academic wants to do this and go on this exciting journey. I have zero regrets.

“Do not wait until it’s until it’s perfect. Good is good enough.”