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Antora Energy’s ‘sun in a box’ decarbonizes industrial heat
When you think of energy storage, you think of lithium ion batteries. But Antora Energy has developed a zero-carbon thermal battery that is safer, longer-lasting, more efficient, and cheaper than anything available today. Antora turns wind and solar into 24/7 power and heat and sets industry on a course to cheap, clean, around-the-clock energy. Now with $50M more in the bank, Antora will help solve the industrial heat side of the clean energy equation. We sat down with Andrew Ponec, founder of Antora about the falling cost of renewables and how that enabled their journey to developing Antora’s ‘sun in a box’ battery.
Where does thermal heat fit into the clean energy equation? What’s the scale and scope?
Heavy industry accounts for a massive 30% of global emissions, and industrial heat is a big part of this. Heat is used in almost every industrial process from extremely high temperatures used for cement calcination to lower temperature uses like steam.
Displacing fossil fuel-driven electricity is in many ways easier than displacing fossil emissions from heat. The process of converting fossil fuels to electricity is only 30-50% efficient, which alone more than doubles the cost. Adding in power plant operational costs ends up with electricity priced at 5-10x the original fuel. Solar and wind can now easily get to cost parity with fossil fuel electricity, whereas the conversion process from fossil fuel to heat is efficient - humans are masters at burning stuff. To replace fossil fuels with renewables to produce heat means competing with the initial low baseline fossil fuel cost.
From a technology perspective, it's actually quite easy to turn electricity into heat. For instance, we’ve operated electric boilers for decades. It’s economics, not technology, that makes industrial heat so fundamentally hard to decarbonize. The good news is that renewable electricity has punched through LCOE equivalency with fossil fuel electricity, and continues to drive prices down. The challenge is with the intermittency of renewables since industrial processes tend to run 24/7. If operation only happened when the sun was shining or the wind was blowing, these enormous plants could never pay back the upfront capital cost. Antora was born specifically to smooth out renewable energy intermittency to power industrial processes with renewable heat.
Why hasn’t this been done before? What enabling technology changed possible outcomes?
Super cheap renewable electricity availability unlocked this. Thermal energy storage has a long history in industry. The most recent application was in concentrating solar power (CSP), where heat from a power plant is stored in molten salts. But there’s a limit to the amount of input temperature molten salts can store, which limits CSP’s applicability in industrial uses.
Electricity is a low entropy source of energy, so it’s perfect to start with - you can create any temperature you want! Electric arc furnaces for steelmaking use an electricity driven process to reach temperatures over 1500°C. But historically, powering thermal energy storage directly from electricity was prohibitively expensive - declining renewable electricity prices was the fundamental shift we needed to start Antora.
What’s Antora’s founding story and your personal climate journey?
When I was an undergrad at Stanford, a group of wonderful people and I started a company called Dragonfly Systems, a power electronics company in utility scale solar. We were acquired by SunPower, so I took a break from undergrad and worked in industry for a few years. During my time inside the solar industry, I saw firsthand how fast renewable costs were dropping and this concept coalesced that this amazing new tool - very cheap, clean electricity - could be applied in structurally impactful new ways to other climate challenges.
People from the solar industry are notorious for taking the same cost-down effect and founding great companies in adjacent markets. Electric Hydrogen comes to mind; I met Raffi Garabedian when he was CTO of First Solar and I was at Dragonfly. The low cost of renewables writing was on the wall, but the exact mechanism for how to apply it to climate wasn't clear to me yet. I went back to Stanford to finish my degree, where I met one of my two co-founders, Justin Briggs. We started talking about climate applications for what to do with this massive amount of cheap renewable electricity. We eventually narrowed in on storage. We looked at hydrogen, compressed air, gravitational energy storage, flow batteries, lithium ion batteries… you name it.
We wanted our work to be additive to the rest of the brilliant entrepreneurial efforts already directed at storage. At the time, we saw the biggest gap between the scale of climate impact and the number of people working on the problem in Long-Duration Energy Storage (LDS). Since our founding, it's become increasingly clear that LDS, for both heat and electricity, is essential.
We met David Bierman, our third co-founder, through our advisor, Brian Bartholomeusz from the TomKat Center, who saw him pitch at an Activate event. Brian said to David “I'm so glad you're working with Justin and Andrew,” because David was presenting about LDS exactly the same way we were! We met up for coffee and easily could have been competitors, but instead we decided to drop our guard and tell each other everything to see what came of it. Of course, it was amazingly productive and we learned that we really enjoyed working with each other. With the support of the Activate fellowship and program, we merged the two companies together almost right off the bat.
So what does Antora do?
There are three aspects of the technology: the storage, heat transfer mechanism, and conversion to useful forms.
Let’s start with storage. Everything done in thermal storage was approached with limits in mind based on concentrated solar input. If you throw that out the window and start from scratch, you want to go to as high a temperature as possible for two reasons. First, you need to operate at really high temperatures in order to serve the industrial market. Second, the cost of storage depends on temperature. The amount of storage is proportional to the change in temperature between charging and discharging the battery. If you want to store more energy, you need to increase the high end temperature hotter and hotter.
Solid carbon was our aha moment for the storage material. We made spreadsheets of every material you can imagine to store heat. We realized solids would be ideal for storage since it would eliminate the complexity around leaks, freezing, pumps, pipes, and valves associated with liquid storage mediums or packed beds. Carbon is also very cheap. Solid carbon is one of the largest produced commodities in the world - used in the steel and aluminum industry. It has a massive heat capacity and is extremely temperature stable. The first light bulbs had carbon filaments because you can get carbon up to over 3000°C and it's still solid. We get these high temperatures with carbon because we're charging with electricity not CSP.
The second thing that you need is how to get the heat out of the storage. In the past you’d use convection as the heat transfer mechanism - flowing some fluid like a liquid or gas through the storage medium which then goes somewhere else. But with high temperature storage, radiative heat transfer becomes a very powerful way to move heat. Radiative heat transfer is proportional to temperature to the fourth power, which is a mind bogglingly large scaling factor - 2X the temperature gives you 16X as much radiative heat transfer. If you open up some cavities which beam out light, you can deliver a tremendous amount of heat.
All this heat coming out in the form of light is very flexible. You can put whatever you want to heat in front of that beam of light like a tube to generate steam to run your industrial process. Since we're already talking about light, we can also use photovoltaics to convert that directly back into electricity. We're able to put in a simple heat engine - photovoltaics to intercept that light and convert it back into electricity at very high efficiency.
What scale of industrial heat can Antora deliver? How does that play into your go to market and initial customers?
Our system can deliver very high temperatures up to above 2000°C, which includes industrial processes like heating up cement kilns. However from a market perspective, we’re starting with the lower hanging fruit. Our first product is for temperatures below ~300 °C, which makes up more than half of industrial heat used. It's also an easy integration challenge since these customers use steam.
We’re looking at a few different sectors for where to enter. One is chemicals - chemicals use a lot of heat and steam in their processes and require big plants, which means big customers, big wins, but a harder sales process. Another interesting category is fuels producers like biodiesel, ethanol, etc. The LCFS market in California is one of the biggest carbon markets in the world. Anybody selling liquid fuels into California has an effective high carbon price, which means they really don't want to burn natural gas anymore for heat - which is where we step in. Those areas are likely to be some of our earliest deployments. One other category is in food and beverage, where there is no carbon price. It's a good test case for us to see if we can go head to head with natural gas. In terms of geography, we’re focused in areas with low cost renewables such as in the wind belt or in places that are really sunny, like the southwest.
How does Antora’s revenue model work?
Typically, we're looking at heat-as-a-service type contracts or sometimes steam-as-a-service or hot-thermal-oil-as-a-service. We’ll come up with better acronyms in time, but usually it’s some sort of energy purchase agreement type transaction. There are also customers that have wanted to buy systems outright, which surprised us. One of the things that pushed us towards a service type model, is that you have to be really thoughtful about where you're getting the input electricity. If it's a plant in the wind belt, you want wind when it's very cheap at wholesale price without having to pay the standard industrial tariff. We need to go behind the scenes to get direct access to cheap wind electricity in order to get really inexpensive heat and - that lends itself to an as a service type model.
We’re seeing more and more young founders in climate hardtech. Who have been the supporting actors along the way and what are the resources needed for 100 more Antoras?
There are so many more people that have helped us than I could possibly go through here. There’s an incredible ecosystem in climate tech, where all these companies are so mission driven, that people in this space seem more willing to help out and give time. First of all, we’re just really appreciative across the board to everybody willing to give a couple hours of their time. Within the Stanford ecosystem, there's the TomKat Center for Sustainable Energy and Brian Bartholomew in particular has built an amazing ecosystem of innovation there. A huge number of climate companies can trace their roots to them. That was the very earliest community that boosted us.
The next one is Activate. Through Activate, we were brought into the community - the founders and people in the program itself - who gave us a tremendous amount of time and advice about fundraising, grants, communications, all of that. It's amazing and unlike anything else that we know of. I don't even want to think of the hypothetical of what Antora would look like without Activate. There’s a growing ecosystem of investors who are willing to invest earlier, but I think programs like Activate are core to generating high quality founders needed to solve these hard climate problems.
Who do you look up to as a disruptive leader in the climate tech space?
The first name that comes to mind is JB Straubel, the former CTO of Tesla and now CEO of Redwood Materials. When we were at Dragonfly, we did a business plan competition in 2013 before Tesla blew up. After our presentation, he identified all of the major challenges we were going to hit in a few minutes with a precision that was unnerving. He’s just an incredible technologist and really understands commercialization. He was also just incredibly kind and humble. He took me and my co-founders at Dragonfly on a tour of Tesla and gave us some great advice on how to start a company. That combination of things in one person, the incredible business and technical skills and human kindness, is something that I really respect about JB.
You've had a lot of success in a short amount of time. Is there anything looking back that you would have done differently?
There are many things - we are far from perfect. In our journey, I think all of the things that I would say center around how we can go faster because we're here to help solve climate change. We did a decent job but we could have been more aggressive to find ways to get money in the doors sooner. As soon as you really believe you have the right idea, don't wait around too long. If you can find those great investors, who are here to support entrepreneurs and their journey, it’s such a powerful accelerant. At Activate, you really saw a divergence between the companies that raised money relatively early, and then were able to do that hiring and run more experiments to start scaling faster. As a team of engineers, we underinvested in all the parts of the business that weren't around engineering. I think we could have pulled in more of the infrastructure on the operations side sooner and done a better job there.
Congratulations on raising your $50m Series A, announced earlier this week! Who’s involved, and - most excitingly - what’s next for Antora?
We couldn’t be more thrilled with the group of investors who joined us for our Series A. The round was led by Breakthrough Energy Ventures and Lowercarbon Capital, with incredible new venture funds like Trust Ventures, Overture VC, Grok Ventures, and Impact Science Ventures joining alongside our longtime supporters at Fifty Years (read 50Y’s memo here). We’re also lucky that Shell Ventures and BHP Ventures joined the syndicate from the corporate side. This group is in it for the long haul - they understand the twists and turns to come, in order to make the level of difference that we want to make.
In terms of what comes next, we’re scaling up from large lab-scale prototypes to small commercial installations. Those prototypes are a stepping stone towards building real, larger ethanol or chemical plants. In order to get there, we’re building out the team!
We want to hear from folks across every aspect of the business who are either already in climate or who are thinking about getting into climate. If you’ve got a skillset that you think could be useful to our company, and you’ve got a burning passion for meaningful work, we want to hear from you. As a founding team, we've spent a lot of time vetting solutions and thinking about how Antora can most effectively solve this huge climate problem. Nobody wants to waste a few precious years of their life. We’re confident that working at Antora is a high value way to spend your most precious resource - time - to impact climate change. We’re all here for that reason, and we’d love to find more people who think that way.
If you’ve got a white-hot passion for meaningful work, and also believe that there’s no “next time” to decarbonize our planet, Antora wants to hear from you! They’re hiring across the business and their inbox is wide open. Likewise, drop a line if you’re at an industrial or manufacturing company looking for a solution to source reliable, clean heat.
Antora is a case study in the potential climate impact unlocked by supporting entrepreneurial scientists. Activate, the fellowship which brought Antora’s co-founders together, is looking to secure funding to support as many top candidates for the next Activate cohort as possible. Want to help? Reach out to Activate—you could help bring the next Antora to market!
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