How can we address the carbon emissions from diesel engines, which are deeply integrated into global economies but also present significant environmental challenges?

While electric vehicles are often highlighted as the solution, ClearFlame presents an immediate and innovative alternative that drives us toward a cleaner future—without the need to wait for EV infrastructure to catch up.

In this discussion, BJ Johnson, co-founder and CEO of ClearFlame Engine Technologies, shares how his company is offering a practical solution by decarbonizing traditional diesel engines.

We’ll explore the story behind ClearFlame, understand their technology, and discuss its implications for the future of clean energy.

🎧 Listen or watch the episode

👤 Interview with BJ Johnson

Dunya Jovanovic: We'd love to hear about your background and how you found your way into the cleantech industry.

BJ Johnson: I’m BJ Johnson, co-founder and CEO of ClearFlame Engine Technologies. My journey into this space began with my engineering background; the technology that eventually led to the founding of ClearFlame was originally part of my graduate research at Stanford University in California. We started the company in 2016 and relocated to the Chicago area, where we've been expanding ever since. ClearFlame’s mission is to modify traditional diesel engines—the big engines in semi-trucks or larger power generators—to use low-carbon fuels. For applications that aren’t yet ready for electric vehicles and still need diesel engines, we offer a solution that provides the required performance but without relying on petroleum diesel fuel. This allows us to reduce carbon emissions significantly and offers a low-cost alternative for customers, particularly in commercially oriented sectors.

DJ: What initially sparked your interest in developing cleaner alternatives for heavy-duty engines?
BJ: My interest was greatly influenced by Chris Edwards, who became the thesis advisor for both me and my co-founder, Julie Blumreiter, at Stanford. He often spoke eloquently about the dual aspects of the energy problem. On one hand, we must achieve sustainability and drive down carbon emissions. On the other, there’s a strong correlation between access to energy and quality of life. To improve global quality of life, particularly in the Global South, energy consumption has to increase, which seems to conflict with sustainability goals. This is where the idea of decarbonizing the diesel engine came in. Diesel engines drive global economies and are especially critical in developing economies. While we need the engine design to persist, the diesel fuel itself contributes about 5 gigatons of CO2 annually—around 12% of global CO2 emissions. So the challenge became addressing the problem of diesel fuel with a technology that wasn’t yet on the market. At the time, the narrative was largely binary: either diesel or electric vehicles, with nothing in between. But there’s a significant market need for something in between, and that’s the gap we aimed to fill.

DJ: How does your technology work, and how successful has it been so far?
BJ: The core of our technology is a higher-temperature combustion process. We modify a bit of the engine’s plumbing, essentially redirecting the airflow and exhaust to create hotter conditions. We also make a few other modifications and a lot of changes to the engine’s controls, but in the end, it only involves about 5% of the engine’s parts. We partner with professional diesel engine rebuilders to implement these changes, enabling the engine to run on lower-carbon fuels. As for its success, the proof is in the results. The modified engines maintain the torque, power, and efficiency of traditional diesel engines and even sound the same—though the diesel engine’s characteristic noise isn’t always a positive feature. This similarity allows us to deploy trucks with customers today, pulling 80,000 pounds and running 23 hours a day, since they can be quickly refueled with liquid fuel. We’re proud that our technology enables customers to maintain their operations while significantly reducing their carbon footprint, with current reductions of at least 50% and a pathway to net-zero emissions by the next decade.

DJ: How does the cost of operating a ClearFlame engine compare to traditional diesel engines?
BJ: Currently, we’re deploying trucks under a leasing model. We approach customers and ask them to consider what they’re paying today for truck operation, including maintenance and diesel fuel. About half of the big trucks you see on the road are already leased, so this model isn’t foreign to most fleets. We then offer to beat their current cost slightly, providing them with a small discount depending on their specific operations, such as load weight and fuel efficiency. This comparison is apples to apples; whatever they’re getting with diesel, we can beat that price point. Importantly, we take on the financial risk by not asking for any upfront payment. Customers simply pay us per mile as they go, at a rate that’s lower than what they would pay for diesel. We also provide the truck, maintenance, and even the fuel if needed.

DJ: You mentioned that when it comes to achieving net zero, EVs are often the go-to solution. How do you position ClearFlame's technology within this broader landscape of biofuels and EVs?
BJ: That’s a great question. ClearFlame’s technology has two major differentiators. First, we serve as a bridge technology that works today. Our solution utilizes the same supply chains, technician training, and infrastructure as traditional diesel engines, making it easy to adopt without major changes. This contrasts with EVs, which are about 60% to 90% more expensive over their lifetime, even when considering lower electricity costs. You can’t integrate something that’s so much more expensive into a business that operates on 3% to 5% net margins. Second, we’re not asking anyone to compromise on their sustainability goals to adopt this bridge solution. We’re a bridge to a sustainable future, not a bridge to nowhere. The fuels we use today are, on average, lower in carbon than the typical grid electron used by EVs. Moreover, these fuels are decarbonizing faster than the grid and are on a pathway to achieving net negative carbon intensity scores. This means that every mile driven with our technology could effectively remove greenhouse gases from the atmosphere.

DJ: What challenges have you faced in developing and scaling this technology?
BJ: Developing new technology is always challenging. We’ve had to overcome various technical obstacles to reach the point where our technology is operational with customers today. One of the biggest challenges during the development phase was proving that this technology matters. Diesel and EVs are well-known, but where does something like ClearFlame fit in? We’ve had to do a lot of educating to show that there’s a middle ground and that it’s viable. Scaling presents its own set of challenges. We’re still a relatively early-growth startup with about 45 people, so everyone wears multiple hats. We’re in the phase of proving that the tech works and scaling it from one to ten, to a hundred, to a thousand. This requires not just technical expertise, but also a solid commercial strategy.

DJ: As ClearFlame gains traction, do you see government policies playing a role in your success?
BJ: Government policies could certainly play a role, though ClearFlame’s strength lies in the fact that we’re not dependent on them. Our engines aren’t subsidized, and while biofuel growth was subsidized for a time, those subsidies, particularly for ethanol, have since ended. This means we operate in an unsubsidized world, making us less sensitive to government policy. That said, intelligent government policy could help us. For instance, instead of mandating the adoption of EVs, we could incentivize the adoption of lower-carbon solutions. This approach allows customers to choose what works best for them while still contributing to decarbonization. A policy that focuses on outcomes—like reducing carbon emissions—rather than the specific means—whether it’s EVs or combustion engines—could lead to faster and more widespread decarbonization.

DJ: What recent developments at ClearFlame are you most excited about?
BJ: We’ve recently crossed the threshold into becoming a post-commercialized, post-revenue company. We started rolling out our product with customers in early July, primarily in Iowa, and we’re excited to be deploying trucks full-time with customers and generating revenue. My ask to the audience is that we’re looking for like-minded fleets. Many companies want to reduce their carbon intensity but struggle to find an economically viable way to do so. ClearFlame offers that solution, allowing companies to become market leaders in sustainability without incurring higher costs. It’s a powerful message that resonates with a market that’s missing that voice today.

DJ: Have you received any feedback from the fleets you’ve partnered with? Did they have any reservations about adopting this new technology?
BJ: There’s always some level of skepticism when it comes to new technology. Customers want to know if our engines can perform as well as their diesel engines. Interestingly, much of the feedback we receive is unrelated to our technology itself. For example, customers care about the rear-end ratio of their trucks—a standard diesel truck specification that converts engine motion into wheel motion. If this ratio isn’t right, the truck won’t perform as expected, so we’ve had to learn and adjust on the fly. Customers also care about the truck’s color—again, it has nothing to do with our technology, but still something that matters to them. These are valuable lessons for us because they’re easy to address, and getting them right is crucial for customer satisfaction. We need to understand and meet these expectations, just as any diesel OEM would.

DJ: As a founder, what advice would you give to someone looking to enter the cleantech space?
BJ: My advice applies not just to the clean tech space, but to entrepreneurship in general: just go for it. The worst-case scenario is that your company fails, and that’s a very real possibility for any startup. But whether you succeed or fail, you’ll learn so much more from the experience than you would in a consultancy or a large company. There’s nothing wrong with those career paths, but if you want to be an entrepreneur, the best thing you can do is try. Even if you fail, you’ll be smarter the next time you try to start a company. In the context of cleantech, I’d encourage aspiring entrepreneurs to consider starting their ventures. When we were starting ClearFlame, we considered working for a big engine company to try to convince them to adopt our technology. But it’s hard to change traditional industries from within, especially in something as entrenched as the energy sector. It’s up to us as entrepreneurs and innovators to prove that something new can work and then help the industry adopt it. If you want to see change, there’s no substitute for proving that change is possible yourself.

DJ: Do you think the landscape for clean tech has changed since before the pandemic? It seems like cleantech has become more mainstream now.
BJ: You’re right. A lot has changed, particularly around the 2020 election, which brought cleantech back into the spotlight. These things do go in cycles. For example, in 2008-2009, cleantech was seen as a great investment, but by 2013-2014, it was considered a bad idea. Then, by 2020, it was back to being the best idea ever. Now, we’ve come back to earth a bit, but these cycles will continue. One advantage of being an entrepreneur is that you can ride out these cycles. I’m not evaluated on quarterly analyst reports like a CEO at a Fortune 100 company might be. My performance is assessed on VC funding cycles of 12-18 months, which allows us to weather faster-paced market fluctuations. There’s also a lot of geographic variation in entrepreneurial activity. The West Coast and Northeast are more willing to take on entrepreneurship, but that’s simply because there are more examples, and it’s more normalized there. I’m encouraged to see this becoming more common in the Midwest as well because we need entrepreneurs across the country to solve energy challenges. Energy is a global problem, and different regions face different issues that need to be addressed.

DJ: Where do you see ClearFlame in five years?
BJ Johnson: In five years, I want to see the vision of ClearFlame taking off. I don’t want it to be just ClearFlame trucks; I want to see ClearFlame engine technologies in off-road equipment like backhoes, tractors, mining rigs, and power generators. I also hope to see other incumbents following in our footsteps. Just like Tesla showed GM, Ford, and others that EVs were a good idea, I believe ClearFlame will set the example for companies like Daimler, Volvo, Paccar, and Cummins. I’m excited to see more companies adopting our technology, not just us, based on what we’ve proven about the market. Customers fundamentally want the performance of diesel engines, and there’s a way to achieve that with low-carbon fuels.

📝 Full episode transcript

Hi BJ, and welcome to the Green New Perspective Podcast! Thank you for having me. So can you give me a short? Me and our audience a short introduction. Tell us a bit about your background and how did you end up working in this clean tech space? Absolutely. So I'm BJ Johnson. I'm co founder and CEO at a company called Clear Flame Engine Technologies.

I'm an engineer by training. So the technology that became Clear Flame had originally been my graduate research out at Stanford University in California. Started the company back in 2016, where we moved to the Chicago area shortly after, and we've been growing it here since what Clearflame does is modify traditional diesel engines.

So I think the big engines that are in, semi trucks or larger power generators. We modify those to use low carbon fuels. So applications that aren't ready for an electric vehicle that still need the diesel engine, we can provide that performance need, but we can do it without relying on petroleum diesel fuel, which means we can not only be Low carbon for customers more importantly in these commercially oriented sectors, we're actually low cost for customers as well.

And what sparked your interest in developing this cleaner alternatives for heavy duty engines? The professor who became both Julie and my thesis advisor, Chris Edwards out at Stanford, he would always talk very eloquently about there being two sides of the energy problem. That yes, of course we have to achieve sustainability.

We have to drive down carbon emissions. But also the fact that there's basically nothing in the world that's more correlated with quality of life than access to energy. And so if we're going to improve global quality of life, particularly in the global south, we're going to have to increase energy consumption.

There's no way around it. And so those two things appear to be at odds. We have to increase energy consumption, yet become more sustainable. And that's where this idea of decarbonizing the diesel engine came in. Diesel engines drive global economies. We're reliant on them here in the U. S. We're even more reliant on them in developing economies.

We need that engine designed to persist, but diesel fuel contributes about five gigatons of CO two every year. So it's about 12 percent global CO two emissions. So that was the idea. How do we do something about an engine we need? But the fuel being the problem and actually addressing that with a technology that no one was talking about yet.

We were still living in a world where, we were either going to use diesel or EV, but there was nothing in between. There's a huge range of applications that need something in between, and that's a market need we wanted to meet. And how does your tech actually works and how successful is it? So the way the technology works.

to go into as much detail here, but it's basically a higher temperature combustion process. So we change a little bit of the plumbing, the way that the air and the exhaust moves in the engine, we redirect those flows to make them hotter. We make a few other modifications to the engine and then a lot of controls changes, but really that amounts to only about 5 percent of the parts.

So we work with professional diesel engine rebuilders to change about 5 percent of the parts of the engine. And then you can make this engine run on a lower carbon fuel. And that goes to your question about how successful it is. The proof is in the pudding, so to speak, like it does everything that diesel engine does today.

We're able to match the torque and the power and the efficiency even sounds the same, which is not always a good thing. Diesel engines are a bit loud, but it is a diesel engine in every sense of the word. And that's what allows us to be on the road with customers today. Pulling 80, 000 pounds, running 23 hours a day, because you can just refill it quickly with a liquid fuel.

I'm doing everything the diesel truck was doing in that application before. That's what we're most proud of. We're not asking customers to change the way they get their business done to use something that is much lower carbon at least 50 percent a day on a pathway towards net zero emissions.

How does the cost of operating a clear flame engine compared to traditional diesel engines? So at Clearflame, we're deploying the trucks under a leasing model right now. So we go to customers and we say about first take a step back about half of the big trucks on the road are leased as opposed to owned.

So it's about 50 50. There's plenty of people using that business model already. We go to them. The to the fleets and say, Hey, what are you paying today to move your goods when it comes to the truck and the maintenance and the diesel fuel? We'll take that and we'll beat that price point by a little bit.

We'll be able to offer someone a discount. And of course, that depends on How heavy their loads are and what miles per gallon they get but it really is an apples to apples comparison Like whatever you're getting on diesel we can beat that and we can do that at no risk to the customer So we don't ask for any money up front.

They just pay us per mile as they go Again a rate lower than diesel and we're providing them the truck the maintenance and if they need it the fuel as well You mentioned that when we talk about achieving net zero We are usually relying on evs. So let's say biofuels so how do you market your tech?

Yeah, it's a great question. There's two ways in which I think it's important to, to talk about Clearflame's technology that really differentiate it from everything else. One is we do have the ability to be a bridge technology. In the sense that we are a technology that works today.

We use all of the same supply chains as a traditional diesel engine. We use the same, all the same technician training as a diesel engine. We use infrastructure. That's extremely similar to that of a diesel engine. We're able to keep all of that in place today. So I think when it comes to marketing it, saying we can have an impact where their solution today is one of the big differentiators, contrast that with EVs, which work pretty well in passenger cars today.

Okay. But for an EV truck, that's about 60 to 90 percent more expensive to own over its lifetime, including reduced electricity costs. So you can't put something that is 60 to 90 percent more expensive into a business that has 3 to 5 percent net margins. So that's the first aspect of the answer.

We can have an impact today, but the second aspect is we're not actually asking anyone to take a step back on their sustainability goals to adopt this bridge solution. In other words, it's not a bridge to nowhere. It's a bridge. I think that continues indefinitely. The fuels we use today are actually lower carbon on average.

than a typical grid electron today. So we're actually lower carbon per mile than that EV truck today, and the fuels we're using are actually decarbonizing faster than the grid and have a pathway to having net negative CI scores, carbon intensity scores, which effectively means that every mile you drive, you're having the net impact of pulling greenhouse gases out of the atmosphere.

So if you can be better today, easy to adopt today, okay. And carbon negative in the future. I think that is a full spectrum of what you need to disrupt the market. Now, transform the market now, more importantly, but persistent, definitely as part of a sustainable future. And what challenges did you have while developing the tech and while scaling it?

Yeah, so I think challenges while developing of course developing technology is always hard. So there's a lot of technical challenges that we've had to overcome to get to the point we're at today, actually operating with customers. I think some of the bigger challenges during the development phase is proving that this technology Matters, this is not something people have heard of.

They've heard of diesel. They've heard of EV. So where do you fit in the questions that we've just been talking about? There's had to be a lot of education around that. And it's a market that can be a little bit resistant to change. Look at EVs. If you rewind 10, 15 years. Everyone was saying EVs were a dumb idea and Tesla was going to fail.

But now that Tesla is the most valuable car company in the world, everyone is making EVs as well. I think Clearflame is going to have to pay a play on that similar kind of market transformation curve. In terms of the challenges with scaling, we are still early growth stage startup of about 45 people.

So it's a lot of people wearing a lot of hats and we have to just continue getting better at customer support, customer service, scaling up our sales. We've proven the tech works. Now we are literally in the scaling phase of it. Can we turn one to 10 to a hundred to a thousand? And that becomes as much a commercial strategy exercises, the technical challenge one.

And when we talk about widespread adaptation, might government policies play a role? Very good question. Certainly government policies could play a role. Now, one of the things that I think is Clearflame's Strength is that we're not actually really reliant on government policies today. Like our engines are not subsidized in any way.

And while the growth of the biofuel sector had been subsidized for a while, all subsidies at the biofuel level, at least for ethanol are gone as well at this point. So we exist in an unsubsidized world, which means we're not super sensitive to government policy. That said, I do think intelligent government policy can help us.

For example, rather that mandating people adopt EVs, we can incentivize people to adopt lower carbon solutions. I think that's an easier policy to sell to the market because it allows customers to choose what makes sense for them. I think it actually also makes more sense for the environment.

I don't think a policy that says, An EV that might be getting recharged by a diesel generator, which is happening a lot these days, that should not be treated as cleaner than a combustion engine that is running on a carbon negative fuel. So by incentivizing the outcome, decarbonization, rather than the means, EV versus engines, I think we'll get more reception to decarbonization and as a result, faster decarbonization, which is ultimately what we all want.

And what recent developments or announcements are you most excited about within Cleveland? So we have recently crossed the hurdle into being a post commercialized post revenue company. So started rolling out, thank you, started rolling out our product with customers in early July running largely around Iowa.

So we're excited to say, Hey, we're actually deploying the trucks full time to customers and making money on them. My, my ask to the audience is always, we're looking for like minded fleets. I think there are a lot of customers out there that want to do something good to lower their carbon intensity.

No one is out there saying, I want to leave. The world, a worst place environmentally, but if your choice is do something about carbon or keep your business afloat because your margins are very thin, of course you're going to choose the ladder and no one should be demonized for that. People that are looking to do that right thing and yet haven't found an economically viable way to do it.

That's the kind of customers that we're looking to work with. And I think there's a huge value that we offer those customers because then they're allowed to become market leaders. And go to all of the big brands of the world, the Nike's and the Ikea's to be able to say, Hey, we can move your goods sustainably and we don't have to charge you more for it.

That's a really powerful message and a market that is missing that voice today. And do you have some feedback that you can share since you've partnered with some of the fleets and did they had any prejudice since this is a new tech? Yeah. The, there's always some prejudice for new tech. I think really what it comes down to is, they're really evaluating, does it do everything my diesel engine did today.

And so a lot of the things that we learn about our trucks have nothing to do with our technology. For example in the trucks there's something called the rear end ratio, which is what converts the engine motion into the wheels turning that can vary truck to truck. And if you give the customer the wrong rear end ratio, again, standard diesel truck spec.

It will not give them the performance they're used to. So we've had to actually learn that and change it on the fly. Customers also care about what color the truck is. Nothing to do with our technology, but something that you shouldn't get wrong. So a lot of the feedback is about, Hey, this is like fundamentally working, but you should have done X, Y, and Z different because that would have been easy to do.

And that's been good learnings for us because the customer is right. Those are things that are easy for us to do, and we can do a better job actually figuring out exact. Figuring out in advance what exactly do you want your truck to look like? Because that's the same question any diesel OEM would be asking them to.

And you started the company yourself, so what advice With my co-founder? Yeah. With your co-founder. Yeah. What advice would you give to someone who wants to follow your path and enter this Cleantech space? And I would actually apply this advice even more broadly than just the clean tech space, which is just go ahead and do it.

The worst thing that is going, that can happen is that the company will fail. And that's, that is the most likely outcome for any company. Startup, right? But at the end of the day, that really is the worst thing that can happen. And regardless of whether you succeed or fail you're going to learn so much more doing that than you would if you were, going into a consultancy or working at a large company.

And, there's nothing wrong with those careers as well, but if you want to be an entrepreneur, the best thing that you can do is try. Cause the worst thing that happens is that you fail and then you're smarter the next time you try to start a company. That's the broadest advice I would give.

And then specifically on clean tech I would really encourage people to think more about the entrepreneurial routes. When we were starting clear flying, one of the questions was, do we want to go work for one of the big engine companies and just try to convince them to do that?

And it's really hard to change traditional industries and energy is about as traditional in industry as there is out there. It's hard to change from the outside. It's not because they're bad people or bad companies. It's just because they have established business models that have worked for decades.

So the onus is on us as entrepreneurs and innovators to show that something else can work and then help them adopt it. Especially for clean tech, if you do want to see change I really don't think there's any alternative close to proving that you can make that change happen yourself. And do you feel that adaptation of change.

Has actually changed now since, let's say before the pandemics. Because I feel like cleantech has become more mainstream than it was then. Yeah. I think you're right. A lot happened around the 2020 election that made cleantech popular again. These things do go in cycles, ultimately it's.

driven by what the financial markets want. We, back in 2008 to 2009, everyone thought clean tech was going to be a really great investment thesis by 2013, 2014. Everyone thought it was a terrible idea by 2020. Everyone thought it was the greatest idea we've ever had. Now we've come back to earth a little bit.

So it will be in those cycles. I think that's one of the ways in which being an entrepreneur is important because you can. Ride out those cycles. I am not evaluated on my quarterly analyst report that a CEO at a fortune 100 company would give. I'm still evaluated on my performance, but it's on, B.

Funding cycles of 12 18 month funding increments. And so it allows you to write out some of those faster paced market fluctuations. I do think there's also a lot of geographic variation of that. You see a lot more willingness to take on entrepreneurship on the West Coast and the Northeast. But that's just I don't think that has anything to do with a different set of people there.

It's simply they're just more examples, and it's more normal out there. And I am encouraged to see. It's becoming more of a, more and more of a normal thing here on the Midwest as well because anyone can do it. And actually we need entrepreneurs around the country because the types of problems that people focus on solving on the West Coast are not the same.

That's the type of problems that need to be solved in the Midwest. And so we're going to need all of that to solve energy because energy is a global problem. And ideally, where would you like to see your company in five years? And this whole heavy duty is truck space. Yeah. I think when I want to see Clearflame in five years, at that point, I want to see us making the transition to being a public company, we'll be profitable at that point, but we need to scale ourselves up.

I think more broadly than that, I want to see the vision of Clearflame really taking off. So I don't want us to just be clear flame trucks. I also want to see clear flame engine technologies and off road equipment like backhoes and tractors and mining rigs and power generators. I also want to see other incumbents following in our footsteps.

So just like Tesla. Showed, GM and Ford and in others that, EVs were a good idea. I think Clearflame is going to set that example for Daimler and Volvo and Packer and Cummins to say, Hey, you guys can do this too. And I'm excited to see more companies using our technology, not just us based on what we've been able to prove about the market, that customers fundamentally want the performance of a diesel engine.

There's a way to do that with a low carbon fuel. This is a relatively short conversation. Where can people learn more about you, your partners, ClearFlame? Yeah. Our website is www. clearflame. com. We're most active on LinkedIn. Follow the company, follow me on LinkedIn. It's always very much appreciated.

And if you ever have thoughts, don't hesitate to reach out. So much of ClearFlame support today has been. grassroots of people just being passionate about this idea and driving conversations like this so we can have more awareness of it. So I'm always grateful for those opportunities and to learn more from other people out there and what they're experiencing in this market today.

Thanks BJ. We're here to help and amplify your words as much as we can. Thank you so much. I appreciate that.