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During spring 2023 a new group of nine candidates plan to build Lab-Model v.3

The Green Revolution Energy Converter (GREC) sustainable research at Linköping University will build a physical model. Answers if a real revolving physical "Work Generating Volume" really behave as predicted in our theoretical research? Does theory and reality converge? Is the GREC a future crucial climate-positive concept for an adjustable clean energy production?


The severe impacts of green house gas emissions on the global warming is today a fact. The emissions can be coupled to several different sectors where heat and electricity production were the sectors with the highest increase of CO2 emissions in 2021. The complexity of this turns out to be greater than imagined since no bigger improvements has happened since the Paris Agreement was signed by 196 UN countries in 2015, not even after COP27. Still new technology solutions to inverstigate and luckily there are three new groups at Linköping University in Sweden this spring that thrive on the challenge of a transition to a world not based on fossil fuels. Investigating a new technology aiming to be applied both in the electricity production sector and the transport sector.

The nilsinside GREC sustainability part3 at Linköping University Sweden

The Project Goal

The goal is to build a simple tight model to deliver data in the simplest way within the specified time frame. Time is important. The model does not need to be optimal nor elegant but it has to be able to revolve its Work Generating Volume (WGV) with electric control at different speeds while logging pressure and average temperatures.

The work is divided into three parallel sub-projects/subject areas:

CONSTRUCTION group: Ida H, Andrei T and Simon S

• Building a closed thremodynamic system containing a revolving WGV between convection surfaces. (CONSTRUCTION's group responsibility is to get the Lab Model made within the timeframe)
Phase: Size, Dimensions & Material

GREC CONSTRUCTION group Ida H, Andrei T and Simon S at Linköping University Sweden

THERMODYNAMIC group: Vidar J, Jakob R and Johan Å

• Set up measurable heat transport to and from the model. Preferably with internal sensors for average temperature in convection surfaces and WGV from the MECHATRONICS group. (THERMODYNAMIC's group will focus on setting up and connecting the hot and the cold side for calculations at good operating and measurement conditions)

GREC THERMODYNAMIC group Vidar J, Jakob R and Johan Å at Linköping University Sweden

MECHATRONIC group: Oskar B, Lisa V and Max H

• They will program and setup electronics to measure and logg pressure pulses and deliver to the result to THERMODYNAMIC group (who will calculate the volume change work and calculate real time energy output)

GREC MECHATRONIC group Oskar B, Lisa V and Max H at Linköping University Sweden

The Lab Model version 3

The new LabModel v3, under construction, differs somewhat from the old LabModel v2. Budget, time and the very important goal that it should be TIGHT with MINIMAL FRICTION between the Revolving-Shutter and the large internal fin surfaces for heat convection and the adiabatic fin surfaces (future "moving boundary").

• In order to ensure the experimental runs it has a significantly MORE POWERFUL STEPPER MOTOR.
• Diameter and Volume
- The diameter is around 40 cm (versus 58 on LabModel v2)
- Revolving Shutter in the new LabModel v3 has greater height (thickness 10mm instead of 6mm if I remember correctly)
- The dead volume between the Revolving Shutter and the surfaces inside in volume is significantly smaller in the new LabModel v3 than in Lab Model v2.

• LabModel v3 is only one layer (LabModel v2 has two)
- The shaft thus has only ONE Revolving Shutter

• System limit
- the Revolving Shutter axis crosses the system boundary with sealed ball bearings (LabModel v2 had encapsulated shoulder ends)

• Sensors and Control
- The new Lab Model 3 has an integrated heat source which enables a measurable energy delivery and has a fewer number of built-in sensors.

The GREC Technology

In thermodynamic terms the GREC is a closed system with a moving boundary where the GREC converts heat energy to kinetic energy. The GREC heats up and cools down its internal large sliced WGV efficiently, fast and repetitively, resulting in internal pressure changes.
These internal pressure changes are used by its moving boundary to generate kinetic energy. You may think of the GREC as a revolving Carnot heat engine controlled by computer logics. Please find the theoretical presentation of the GREC on this link:
GREC Theory Presentation

The GREC is a new technological solution to tackle climate change and luckily three groups at Linköping University this spring thrived on the challenge of a transition to fossil free energy systems. The construction and building of the GREC Lab Model v.3 is an important step in a climate positive project that will feed several successful research projects over time...
Please feel free to call or email:

Contact information at nilsinside AB
Nils Karlberg, tel +33 608 53 15 93, theory & technical questions
Sophia Karlberg , strategy & admin questions

The GREC Project