Since 2016, the LHEEA research department of Ecole Centrale de Nantes – CNRS has been investigating a radically new technology for conversion of the far-offshore wind energy into sustainable hydrocarbon fuels. It is called the FARWIND energy system. This energy system is defined as the combination of two essential subsystems: (i) fleets of autonomous energy ships (FARWINDERs) and (ii) tankers tailored to the service of the fleets. Energy ships are ships propelled by wind sails that produce electricity using water turbines attached underneath their hull [Platzer & Sarigul-Klijn, 2009]. They include on-board Power-to-Liquid (PtL) plants for conversion of the generated electricity into hydrocarbon fuels. The fleets’ route schedules are dynamically optimized taking into account weather forecast for maximization of the energy production. The fleets are escorted by specific tankers, which provide support to the fleets (fuel transport, feedstock supply, control, maintenance).
Preliminary studies carried out at LHEEA indicate that the FARWIND breakthrough technology can enable cost-competitive renewable fuel production from the yet-untapped tremendous far-offshore wind energy resource (which is not feasible with current technology (floating offshore wind turbines) because grid-connection, moorings, installation and maintenance costs increase dramatically as the distance to shore and the water depth increase). It has thus a huge potential as a future renewable energy source and for blue growth through the development of the new FARWIND industry.
Scientific advances and innovation
One of the key knowledge gaps preventing the development of the FARWIND technology is the technological feasibility of autonomous FARWINDERs’ fleets. The ambition of the AUTOFLEET_Y1 project is to contribute to adressing this challenge. Thus, the objective of the AUTOFLEET_Y1 project is to develop and validate algorithms and control systems for path following for an autonomous FARWINDER and energy production optimization.
Expected technical and economic impact
The test platform which will be developed in the project will be available to academia and industry for testing new control algorithms for autonomous surface vehicles. The algorithms and control systems developed in the project will be open source.
Key project milestones
- December, 9th, 2019 - Kick off meeting
Results achieved during the first semester of the AUTOFLEET #1 project
- Experimental characterization of the Watt&Sea hydrogenerator
- Conceptual design of the rotors
Results achieved during the second and third semester of the AUTOFLEET #1 project
Development of the experimental plaform
Wet testing on river Erdre (april 2021)
Videos of the tests :
The main outcome of the AUTOFLEET_Y1 project is an energy ship prototype which can be used to develop and validate control systems of such ships.
The prototype includes :
- A catamaran hull (Hobie Cat Tiger, length 5.5m)
- A 2.8m high 0.4 m diameter Flettner rotor for wind propulsion
- A 600W Watt&Sea hydrogenator. It can be equipped with a 200 or 240 mm rotor.
- A control system which allows the prototype to be remotely operated
In collaboration with FARWIND ENERGY, the platform has been tested in July 2021 on the lake of Vioreau (Loire-Atlantique, France). These experiments represents the world-first experimental proof-of-concept of an energy ship propelled by a Flettner rotor.