Celsius Energy: From inspiration to innovation

Celsius Energy started as a flicker of an idea in the minds of three engineers in 2017. Given the ability and space to develop the project alongside their existing roles, Celsius Energy has since grown into a geoenergy forerunner, earning the distinction as one of the top global sustainability leaders at the SEAL Awards.

What is Celsius Energy, and how did it manage such rapid and sustainable growth, from a startup of three to a scale-up of nearly 100 employees and counting? To answer this question, look no further than the company’s founders: Cindy Demichel, Sylvain Thierry, and Matthieu Simon, who leveraged their organization’s investment and support, along with their deep engineering expertise, to build a novel—and highly effective—geoenergy system that significantly reduces carbon emissions in the heating and cooling of buildings. Taking on the challenges of securing funding, consumer education, and scaling in stride, they made the entrepreneurial leap into the sustainability startup space out of a profound sense of urgency, and a desire to make an immediate and lasting impact on the climate.

Here, the leaders of Celsius Energy illuminate their journey in developing tech that utilizes geoenergy—or the heat in the ground below buildings—to regulate indoor climates, and how the right internal incubator program gave them the support they needed to scale their initial innovation into a full-fledged company. These ambitious innovators see the earth below a building as a thermal battery. When it’s cold outside in the winter, thermal energy is extracted from the earth and provided to the building (via a heat pump at the surface) for heating. In the summer, when the building needs to be cooled, thermal energy is extracted from the building and re-injected into the ground. This thermal energy discharge/recharge is a form of interseasonal storage, just like a battery. The system can reduce carbon emissions by up to 90% and cover 80-100% of heating and cooling needs. “Reducing CO₂ is the greatest challenge our world faces for years to come,” explains COO Sylvain Thierry. “For us, there is no choice.” 

On the origins of Celsius Energy

“We wanted a way to make a massive impact in terms of sustainability and to fight against climate change,” reflects CEO Cindy Demichel. “When we realized that 30% of final energy usage and 27% of worldwide CO₂ emissions are linked to building operations (mostly for heating and cooling them)], we thought that naturally the underground had a role to play, and that geoenergy, this energy that lies beneath any building, is something that we need to pursue, industrialize, and massively roll out. That was the starting point.”  

In the early stages before garnering incubating support from senior management, the Celsius Energy founders all held full-time engineering roles, requiring them to develop their ideas in their limited free time. 

“It started as an idea around the coffee machine,” Sylvain reflects. “We dedicated weekends and nights to mature and prove the idea. It was that first sort of ‘undercover’ phase when we matured the idea technically and commercially. We then started to craft a business case. Despite that somewhat uncomfortable time, when we were working a day job and at night, SLB was supportive of new ideas and eventually provided the sponsorship that allowed us to mature it even further.” 

The work-life balance was difficult, but their desire to make a significant and immediate impact drove them to push their idea to the next level. There was no time to waste. After acquiring sponsorship from senior management, as well as support from one of the world’s leading startup incubators), the next challenge was to move the project beyond innovative tech to a plausible, applicable, and scalable business model. 

“For engineers,” elaborates Sylvain, “there’s a tendency to present a new product as primarily a cool new tech idea, but that’s not enough. We went the extra mile to really go outside into the field to learn about the business, to talk to potential customers, and to clarify the idea. We actually changed the technical idea because of where we realized the business was the strongest. That was a very important discovery. So, when we pitched the idea, it was not just a cool piece of tech. It was a business case for a product that could really impact the climate, [at scale and in a profitable manner].” 

On scaling a startup in changing times—sustainably

Amidst strong societal shifts, including public and governmental perception of the climate emergency, the Celsius Energy team had to remain agile. “Even in the five years since we started,” Sylvain reflects, “the world has changed. […] Now, there is no question that the world must put a lot of energy into fixing what needs to be fixed. With that realization, there have been changes for good."

This increased urgency thrust new tech like theirs into the spotlight, earning them further funding and sponsorship, along with recognition from institutions like the UN and the Solar Impulse Foundation. Meanwhile, even French president Emmanuel Macron can be seen introducing geoenergy to the Élysée Palace as part of his sustainability commitments.

“Now,” explains CTO Matthieu Simon, “we have [an end-to-end product], and our focus is to deploy it at scale. Our efforts today in terms of research and development are focused on [digital performance services], industrialization, and cost reduction. The next step is to move it to the mainstream.” 

On education, public perception, and the importance of good science in promotion

As demand and attention grow, so does the need to educate partners, clients, and the public about the science of geoenergy. “One of the biggest barriers is that people do not know about it,” says Cindy. “So, we're working on that.”

As CTO, Matthieu has been invaluable in this regard, offering in-depth technical knowledge to educate and assure customers that the product is scientifically sound. There is also a need for clear and convincing messaging that the wider public can understand. The concept is intuitive—a battery beneath a building gathers calories in the warm summer months and gives them back for heat during winter—and yet obviously complex. Inspiring messaging and aesthetically pleasing product design have been vital in telling the Celsius Energy story. 

“We want to make it visible,” says Cindy. “Even though it’s underground, you want to tell a story. You want to say to the world that you're doing something that is going in the right direction. You want to create something people can be proud of.”

On the future of geoenergy, and how Celsius Energy wants to create it 

“Cooling needs are going to triple by 2030,” elaborates Sylvain. “The climate is getting warmer every day. A future-proof, sustainable solution needs to do heating and cooling sustainably without emitting carbon. So, we have to ask, what is the best solution? ... We see a massive future for [this geoenergy] solution.”

The service-minded attitude that motivated the team as engineers is still what drives them as the leaders of Celsius Energy. “At the end of the day,” says Cindy, “the motto is we have no choice. We need to make this happen.” 

Watch the full interview below to hear more from the trio, their scale-up process, and how they convinced everyone internally that their idea was one worth investing in.