A super-battery aimed at decarbonizing industry

In this episode, Antora Energy CEO Andrew Ponec talks up his company’s game-changing approach to thermal energy storage.

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David Roberts

Back in March, I did a podcast on the possibility of using wind and solar electricity to decarbonize industrial heat, which represents fully a quarter of all human final energy consumption. The trick is to transform the variable energy from wind and solar into a steady, predictable stream of heat by using some form of heat battery.

The idea is that heat batteries will charge when renewables are cheap or negatively priced, around midday when all the solar is online, and then use the stored heat to displace natural gas boilers and other fossil fuel heat sources in industrial facilities.

Among other things, this vision represents a huge opportunity for renewable energy developers — industrial heat is effectively a brand new trillion-dollar market for them to play in. And they can often enter that market without waiting in long interconnection queues to connect to the grid.

Anyway, that episode, which I highly encourage you to listen to at some point, was with the CEO of a thermal battery company call Rondo. In it, I mentioned another thermal storage company whose technology caught my eye: Antora Energy.

Like Rondo, Antora is part of the broad “box of rocks” category, but its tech can do some things that, for the time being, no other thermal battery can do.

I don’t want to say much more here — discovery is half the fun — but I will say I’m as geeked about this technology as I have been about anything in ages. I’ve been thinking about it ever since I first heard about it three or four years ago. Now the company has launched its first commercial-scale system! So I’ve brought Antora co-founder and CEO Andrew Ponec on the pod to talk through how it works, what it can do, and how it could transform industrial heat markets.

So with no further ado, Andrew Ponec. Welcome to Volts, thank you so much for coming.

Andrew Ponec

Thank you for having me, David.

David Roberts

This is so fun for me. I've honestly been thinking about this tech for years and really hoping that you guys would make it far enough to justify me doing a pod with you. So I've been rooting for you. So we're going to get to kind of the role heat batteries and heat storage can play in the energy system a little bit later. But I just want to start with the technology itself. So the basic idea here is you're heating up a rock, right. And what you do with the heat, we'll get to that in a second, but let's just start with the rock itself. Tell me about the material you're using for your rocks and their qualities and why you chose that material.

Andrew Ponec

We looked at a lot of different options for the material that we wanted to store energy in, and there are a lot of different types of rocks, types of solid materials that we might choose. And after a pretty thorough search, we decided to focus on carbon, solid carbon. And that was for a number of reasons. We were looking at different attributes that we thought were important, one of which was cost, one of which was earth abundance. We were also looking for things that had existing supply chains and that were extremely stable and safe for long-term operation.

And when we went through all of that process, carbon came out on top as the best option, although I should say that it didn't come out on top the first time around, actually because of a mistake I made in our spreadsheet. Carbon has a really unique property, which is that it gets better at storing energy as it gets hotter. So the specific heat capacity, its ability to store energy, increases by about a factor of three between room temperature and 800 or so degrees Celsius. So you can imagine what the process would be like to choose a material.

We built a big spreadsheet. We put all of the materials candidates in it. We put what their ability to store thermal energy was, did some calculations on what the cost would be, and then stack ranked them. And in the first pass, carbon was near the bottom, because the mistake I had made was going online and just googling the specific heat of carbon and of course, got the room temperature value. And it was only a few months later, after we were exploring all sorts of other materials, that we kind of went back and looked and said, "Man, carbon has everything we want, except that its storage capacity is really low."

And it was kind of our disappointment in carbon that made us take a second look and then realize this really remarkable property of carbon, that it gets better at storing heat as it gets hotter. And then it was by far the best choice. And that's where we've gone from there.

David Roberts

So I think when most people hear carbon, especially in our space, they think about carbon dioxide, they think about carbon in the atmosphere. So what is solid carbon? What does it look like? What's it used for? Like, what is solid carbon out there doing now?

Andrew Ponec

Great questions. Solid carbon is one of the biggest industrial products that most people have never thought about. We use solid carbon in massive quantities, tens of millions of metric tons a year of this stuff, but it's almost always used as an intermediary in some other process. So the biggest uses of carbon are in the aluminum smelting industry and in the steel industry. So in aluminum smelting, it's actually part of the electrolysis process. And in steel making, electric arc furnaces use it because it's the only material that can survive the hellish environment within an electric arc furnace.

But because none of those go into the final products, we don't think about it very much, even though by mass it's only a little bit behind aluminum as one of the biggest industrial commodities.

David Roberts

Oh, interesting. So part of what falls out of that is, as you say, there is a huge existing supply chain. And so when you say that there's a lot of solid carbon already in use, if it became the de facto material for thermal batteries, would that represent a substantial portion of total solid carbon use? Or is its use so big and so ubiquitous that this is just sort of a marginal thing?

Andrew Ponec

It ends up being a drop in the bucket. We could make terawatt hours of thermal batteries using just a fraction of the carbon that's already processed as part of the supply chains for aluminum and steel.

David Roberts

Got it. So this is a material that is already abundant, already manufactured, already there, ready for you to go. There's no material shortages and what know, people hear materials these days and they think, "oh, what about mining and the social cost of mining" and all that. So what's the sort of like the ESG status of solid carbon?

Andrew Ponec

There are a bunch of different types of carbon, and each of them have different attributes with regard to how much energy goes into them. Are there any other concerns about the supply chain where they're made, are they even mined or are they synthetic? So, just to mention a few. First, carbon comes in many different forms. Diamond is one ve