RegenEAU: Unlocking the hidden energy potential of wastewater

Could you briefly introduce yourself and your company?

I’m Michael Pelletier, co-founder and VP of Strategic Development and Growth at RegenEAU. Our company develops innovative solutions to recover and reuse heat from wastewater in buildings, helping to reduce energy consumption and the carbon footprint of built infrastructure. Our mission is to accelerate the energy transition by transforming a currently wasted resource — wastewater — into a local, renewable and intelligent energy source.

In one sentence, what problem are you trying to solve?

We help buildings drastically reduce their dependence on fossil fuels by recovering the thermal energy already present in wastewater.

How would you explain your project to someone unfamiliar with your sector?

Every day, a huge amount of heat is lost in urban sewer systems. At RegenEAU, we have developed a technology that captures this heat to produce domestic hot water — and soon heating — in a clean, local and much more efficient way.

What sets you apart in your market today?

Our differentiation relies on three key elements:

• ease of integration,
• energy performance,
• and our innovative patented solid-liquid separation system.

We have designed a compact and adaptable solution that enables wastewater heat recovery to scale widely. We are also developing a connected and scalable approach incorporating IoT to optimize energy performance in real time and anticipate building needs.

What is your story with ENGIE?

Our collaboration with ENGIE stems from a shared vision: to concretely accelerate the energy transition in cities. ENGIE quickly recognized the potential of our technology and supported us in a strategic project in France through its subsidiary CIEC. This partnership allows us to combine the agility of an innovative startup with the industrial and operational expertise of a global energy leader.

Why did you choose to collaborate and innovate with ENGIE?

Because ENGIE shares our ambition to develop high-impact decarbonized energy solutions. Their ability to deploy large-scale projects, their technical expertise and their international presence are key drivers to accelerate the adoption of our technology across Europe.

What will you showcase on the ENGIE booth at VivaTech?

We will present our solid-liquid separation technology, which simplifies access to wastewater heat and reduces maintenance. Our goal is to demonstrate that an invisible and underutilized energy source can become a concrete solution for sustainable buildings.

What key message would you like visitors to take away?

The energy transition is not only about new energy sources — it is also about our ability to intelligently recover the energy we waste every day.

This year’s VivaTech theme is “AI: Impact, not illusion.” What role does AI already play in your solution, and how do you see it evolving?

Artificial intelligence will play a central role in the evolution of our technology. We are currently developing internal tools to analyze thermal data, optimize system performance and anticipate building needs in real time. In the long term, we envision energy infrastructures capable of self-regulating autonomously to maximize energy savings and further reduce carbon emissions.

What is your next major challenge in the short to medium term?

Our main challenge is to accelerate our deployment across Europe, particularly in France, while building the industrial and technological capacity required to meet growing demand.

If your innovation fully achieves its potential, what will have changed in the world in five to ten years?

We believe that cities of the future must become circular energy ecosystems. Within five to ten years, we expect wastewater heat recovery to become standard in urban infrastructure, enabling buildings to significantly reduce their emissions and energy dependence. Our ambition is to help make cities more resilient, smarter and more sustainable.