Project:
SUSTAINABLE REVOLUTION at ICAM Toulouse
Promising Results from ICAM Toulouse: GREC — The Green Revolution
Energy Converter Project Advances
Engineering students Michael Peyrony-Rapatout and Pierre Le Provost at ICAM
have once again impressed with a compelling update on their research into the
Green Revolution Energy Converter (GREC) — the groundbreaking sustainable heat engine
concept by Nils Karlberg.
The GREC engine, which operates purely on heat differentials,
represents a novel approach to energy production without relying on combustion.
Over several months, they have studied and tested detailed models using Ansys
and Matlab to simulate the engine’s thermal and mechanical behavior.
🔍 Key Findings
- Performance is driven by three critical parameters: frequency, heat transfer coefficient (HTC), and temperature difference (ΔT).
- Adjusting frequency and HTC together significantly boosts efficiency — a finding that supports and expands on earlier Swedish research.
- In real-world applications, where frequency and temperature may be fixed, HTC optimization becomes the key factor for improving performance while maintaining low costs.
- When HTC is optimized, GREC’s performance approaches that of existing industrial systems in terms of energy output and efficiency.
The team demonstrated that even a non-optimized setup can achieve 6%
efficiency, with extremely low energy consumption for
revolver operation — confirming the system’s potential viability and scalability.
You may download the presentation as a .pdf file by clicking this link:
ICAM GREC Project Presentation in English
🚀 Future Perspectives
The students outlined several strategic paths to take the project further:
- Enhancing heat exchange using a grooved surface model to improve HTC.
- Introducing a heat transfer fluid system via a new pipe-based model.
- Studying geometrical optimizations to minimize energy loss in so-called “dead zones.”
- Designing a low-temperature prototype (limited to 200°C due to lab constraints), including both planning and instrumentation phases.
This latest phase of work highlights both the feasibility and promise
of the GREC engine as an affordable, scalable, and eco-friendly power
solution. The project is now poised for potential funding opportunities .
With their solid research foundation and practical insights, the ICAM team is well
positioned to follow GREC through further simulations and to a working
prototype — and beyond.
👉 Read more about the GREC project and earlier developments
The next phase of the GREC project is being discussed collaboratively by
researchers and partners including:
- Jean-Pierre Fradin, Check Laval,
Alexandre Marie, and the student team at ICAM Toulouse
- Nils Karlberg from nilsinside AB / K.I.T.S. S.A.R.L.
- Guillaume Courty and Anaïs Guiraud
from the Territoire des Hautes Terres d’Oc
Under the coordination of Dr. Fradin, a detailed roadmap proposes five
Work Packages (WPs) for an 18-month low-temperature prototype development, including:
CFD optimization of heat transfer (WP1)
Mechanical and thermodynamic design of the engine (WP2)
Fabrication and assembly of a lab prototype (WP3)
Experimental testing and performance validation (WP4)
Identification of industrial sites suitable for heat recovery applications (WP5)
The project aims to demonstrate a 5-module prototype system, each producing 50W, optimized for temperatures under 200°C using low-cost materials and targeted for TRL 4 (Technology Readiness Level).
💼 Toward Industrialization
The collaboration also outlines potential business models, including:
- Patent licensing and commercialization
- Establishing a manufacturing hub in Brassac
- Creation of a dedicated French SAS (simplified joint-stock company)
to manage IP, partnerships, and collaborative R&D
Initial estimates place required funding at around €185,000, with additional efforts underway to secure equity and co-financing through crowdfunding, capital funding, and regional development programs.
This marks a pivotal step in GREC’s journey — from academic research to
practical innovation, ready to address real-world energy efficiency and recovery challenges.
The GREC is a new technological solution to tackle climate change. Technologists
at Linköping University, Sweden, and at ICAM Toulouse, France, are pushing the challenge
of a transition to fossil free energy systems. Their theoretical research, construction,
building, and experiments with the GREC Lab Models are very important steps
in a climate positive project that will feed several successful research projects over
time to reduce the warming of our athmosphere and to reduce CO2 and other pollutants in
our athmosphere.
Please feel free to call or email:
Contact information at nilsinside AB
Nils Karlberg nils@nilsinside.com, tel +33 608 53 15 93, theory & technical questions
Sophia Karlberg sophia@nilsinside.com , strategy & admin questions
The GREC Project presentation