Country of origin

  • 2017

    Creation date

  • 6


  • €50 k

    Fund raised

Warm air, cold air and steam: lots of energy losses from industrial processes. This valuable thermal resource remains under-exploited. European industrial plants waste around 930 TWh of heat every year; the amount of energy generated by 100 nuclear reactors.

Water Horizon has developed a technology to address this problem in the form of a reversible and mobile thermal battery that recovers and transports waste heat. In other words, the process makes it possible to recover heating and/or cooling resources off-site and between production facilities. Data centres, petrochemical plants and food processing facilities all generate high demand for cooling. The thermal battery is delivered by truck in response to demand for short- and long-term energy supply.

The Grand Jury recognised the importance of this project and awarded it the 3rd Jury prize.

Category: CO2 Neutral Territories

The team

Between them, Jean-Emmanuel Faure, Patrick Lemaitre and Eric-Jean Pankowski cover a wide spectrum of skills, from fluid mechanics to product industrialisation and marketing.

Contact them

4 questions to Water Horizon


It was a visit to the Toulouse wastewater treatment plant that got us thinking. The treated sludge produced by the plant generates a phenomenal amount of heat that has no use in this industrial process. And it didn’t take us long to identify the central issues: all types of industry generate waste heat, often with no solution for recovering that heat. So how could we recover and re-use the hot air expelled by ventilation fans or data servers? On the other hand, district heating networks, shopping centres and cool warehouses all have enormous energy input requirements. There was therefore a resource and a demand, but it took us a few years of studying the problem before arriving at the solution offered by our thermal battery, which redistributes stored heat as heating or cooling.


We’ll be laboratory-testing one of our prototypes this December as part of our partnership with EDF subsidiary Dalkia.


Like a lot of start-ups, we began with very few resources. So our ambition to create an industrial start-up soon ran out of funding. We built the first prototype in one of our parents’ garage, which came with its own hazards... and led to us moving into the garden shed! Back then, we spent so much time in the local DIY store that we were on kissing terms with the checkout staff.


Water Horizon brings industry and environment together by converting industrial waste heat into a renewable energy source. The synergy we’ve created delivers a direct response to two key challenges of the European Green Deal and the Paris Climate Agreement. On the one hand, we’re helping industrial companies to engage effectively with the energy transition. On the other, we’re also making a colossal amount of renewable energy accessible to those who need it. The fact that our technology is reversible, and especially its ability to distribute renewable cooling, makes it possible for us to reach out to consumers that are currently frowned upon for their environmental impact - data centres, for example - but need solutions.

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