Exclusive: Submer's CTO is ready to surf the liquid cooling wave

  • Submer is an immersion liquid cooling company founded in 2015

  • The company is gaining traction as data center cooling needs exceed what air alone can deliver

  • Founder and CTO Pope said it's working with most of the major hyperscalers as well as the European Commission

If your kid wanted to quit school to focus on their bedroom-based data center business, would you let them? Because that’s exactly that Submer founder and CTO Daniel Pope did back in the early aughts. And it turned out to be a very smart move.

Pope’s road to the top of the tech industry corporate ladder hasn’t been one full of internships and MBAs. Instead, it’s been driven by a seemingly prescient vision of what the future landscape looks like.

Today, Pope is the founder and CTO of Barcelona-based immersion cooling company Submer, which is a rising star in the data center liquid cooling space. But his backstory is noteworthy.

Pope grew up between the U.K. and Spain. In an exclusive interview, the CTO told Fierce Network that he started his first business – a data center business – at 16. What started with one server in his bedroom took off “aggressively” thanks in part to the fact that Pope caught the tail end of the Dot-Com Bubble and had his foot in the door early as the cloud began to rise to prominence.

daniel pope rowing
Pope and his teammates rowing in college. (Daniel Pope/Submer)

Though he originally planned to pursue a computer science degree and even got a scholarship for rowing, he was eventually forced to choose between his education and his business. The latter won out.

“So, I didn’t get to go to the university and complete my computer science studies. I’m basically a self-taught tinkerer,” he said. “I learned everything I know about data centers building my own data center. I built three or four different facilities…[and] learned all the challenges of building electrical infrastructure, cooling infrastructure, compute infrastructure and software orchestration to run a data center business over a period of 10 years.”

By the end of the aughts, the business had grown to more than 18,000 servers, and Pope sold it to the Telefonica Group in 2009.  

A star is born

But of course, Pope wasn’t done tinkering. He spent a few years working for other companies – Odin and Ingram Micro Cloud – but felt the founder's itch again in 2015. That’s when Submer was born.

“We saw a clear opportunity and trends and tailwinds for immersion cooling to be a solid solution for the data center industry as all these things converged with climate and AI – well, not so much AI, because in 2015 we weren’t talking so much about AI, but you could see the chip densities increasing and that becoming a problem and that wasn’t going to stop because of Moore’s Law,” he said.

With the advent of large-scale AI, Submer seems to finally be having its moment. Pope said the company has gone from deploying 10 MW of capacity three years ago to 300 MW in the last year alone. All told, it has 400 MW of immersion cooling capacity deployed in production today. Some of that is for crypto mining, but the majority of Submer’s focus is on serving data centers and enterprise customers, he said.

Pope said those upward trends are reflected in Submer’s revenue and headcount as well.

And things only seem like they’ll keep getting better. According to Dell’Oro Group’s latest forecast, the liquid cooling market is expected to hit $3.5 billion by 2028. That means direct to chip, immersion and rear-door heat exchanger systems will make up nearly 30% of the $12 billion overall data center cooling market.

But Pope acknowledged it has taken a while to get to this point. After all, the company is nearly a decade into its journey.

“Timing is the biggest challenge for any startup or any new technology to market,” he said.

“In 2015, we kind of saw the need for immersion, but it was very difficult to pinpoint where there would be such a compelling need that all these barriers to adoption would be overcome” and people would say they don’t matter because there is no other option.

Hurdles

Rising chip power levels and densities are increasingly driving the industry into the arms of liquid cooling solutions. In fact, Nvidia notably just unveiled its first supercomputer system that actually requires direct liquid cooling.

But Pope isn’t blind to the perceived hurdles to adoption that immersion faces. Just the idea of plunking servers in liquid is scary enough. Then there are different operational procedures that need to be implemented. It’s enough to make risk averse data center operators hesitate.

One issue that isn’t a problem for Submer is aversion to the use of PFAS chemicals – because there are none in its single-phase immersion system. And Pope himself is strongly against their use. To him, using PFAS liquids for immersion cooling or even closed loop direct to chip systems is an unnecessary risk.

For those not in the know, PFAS chemicals have been linked to harmful health impacts (coughCANCERcough) in humans. 3M, a former PFAS vendor, announced in 2022 it would stop manufacturing the chemicals and last year inked a $10.3 billion settlement deal related to contaminated water systems.

But there is one huge barrier Submer itself faces. While server vendors have seen the writing on the wall and begun supporting and offering warranties for immersion cooling, the chip vendors by and large have not. The reason? Insufficient demand.

“We’re in this kind of crazy chicken and egg challenge that needs to be broken,” Pope explained. “The very moment that the chip manufacturers support and warranty their GPUs for immersion…then we’re going to see mass adoption of the technology, I have no doubt.”

What’s next?

Pope also made a pitch for immersion cooling as the most environmentally friendly and climate resilient technology, in part because it uses so much less water than evaporative cooling systems.

He noted the European Commission is already a Submer customer and added that the company is “working very closely with almost all the hyperscalers because they see immersion as probably the next technology they need to embrace and implement.”

So, while the company is years into its journey already, Pope said this is really just the beginning for Submer.

“People have started to understand that the TCO for immersion and the future proofing of their infrastructure that the technology brings is a real competitive advantage,” he said. “We’re starting to see the story sticking with more and more people more quickly now.”

But what else is the tinkerer cooking up in his garage?

Pope said most of his hobbies these days focus around home automation and putting together little inventions (there aren’t exactly a lot of places to go rowing in Barcelona, after all). The project he’s working on right now is building an autonomous drone that is connected to security cameras which use AI to recognize wild boars that venture into his garden and activate the drone to scare them off.

Maybe we’ll hear about an ag tech venture soon?