Major technical progress with demonstrator SMARTHyES

The demonstrator SMARTHyES (for SMART Hydrogen Energy Storage) finalized by CEA-Liten and Sylfen in April 2018 incorporates three major advances in the roadmap leading to a commercial product: (1) Design of the reversible electrolysis subsystem, (2) Control of this subsystem, and (3) Hybridization and functional integration.

Smarthyes SYLFEN 2018
  Prototype SYDNEY
TRL 4 5
Design of the reversible electrolyser subsystem


Fluid supply by the laboratory; measurement of the production of hydrogen and evacuation of hydrogen by the vents; measurement of the consumption / generation of electricity dissipated in a laboratory load; no measurement of the heat produced.


Industrial water supply and natural gas network; compression, storage and reuse of hydrogen produced; coupling to the three-phase power network for power consumption and reinjection; measurement of the heat produced.


Control of the reversible electrolyser subsystem


Laboratory control-command: individual manual control of each flow and current or voltage setpoint by an expert technology engineer.


11 pre-programmed operating points; automatic switching from one point to another depending on the setpoint generated by the supervision.


Hybridization and functional integration No integration Hybridisation with Li-ion batteries (10kWh) and a first generation of smart supervision.

An autonomous system outside the laboratory environment: the SYDNEY prototype developed by the CEA in 2014-2015 operated in Grenoble in a laboratory environment managing in particular all fluid flows (deionized water, purified compressed air, laboratory hydrogen, synthetic CH4) and electricity. The demonstrator SMARTHYES is, on the contrary, perfectly autonomous: it is coupled to the electrical network and only needs a supply of industrial water and natural gas network.

The hydrogen produced wasn't valorised, in the laboratory version. It is now recovered and compressed to be stored in canisters. This system was defined jointly by CEA-Liten and Sylfen and designed and realized by AUTOCLAVE-MAXITECH. Hydrogen is stored as a gas at 200 bar, and is then reused by the system when operating in fuel cell mode.

Finally, the demonstrator integrates a Li-ion battery system of 10kWh, developed and delivered by the Grenoble start-up ENERSTONE, which has included an innovation in terms of BMS (battery management system) to manage the balancing between cells.

This demonstrator was also made possible with the help from DEMS (Design), AEI (integration) and EMISYS (Engineering and Project management).


Flexible and automated operation: three power levels are achievable in each of the three operating modes of the system (hydrogen production, hydrogen fuel cell, natural gas fuel cell), i.e. 9 operating points, plus a standby mode and a security mode.

CEA-Liten has developed and coded the strategies allowing the system to automatically switch from one of these points to any other, without any manual intervention, which implies a dynamic control of the flow, pressure and current instructions. Each transition, at this stage of development, lasts a few minutes (the longest being 10 min, and 6 min in average). These durations will be substantially reduced in the future.

This leads to the conclusion that SOFC/SOEC technology is indeed a flexible technology, capable of adjusting its power according to customer needs. And there is no need for an expert to manually control the system!


Illustration : transition time (in minutes) at the launch of demonstration

A service-oriented software supervision: Sylfen has developed and integrated into this demonstrator a first version of its software suite, which drives the entire system. This suite contains a supervision module, developed by Sylfen in the framework of a partnership with NOVENER and the ESISAR engineering school in Valence (France): this module makes it possible to collect forecasts of solar energy production, and the building's energy consumption, in order to call for the calculation of an optimized operating strategy by the optimization module. This optimization module, developed internally by Sylfen, defines a procedure to be followed, which is then implemented by the supervision module. In case of discrepancy between the forecast and the reality, the optimization is relaunched.

The Sylfen software suite incorporates an expert interface and a simplified user interface, allowing an educational visualization of the functioning of the system, particularly in the context of visits. It finally integrates a set of big data tools to record, export, archive and exploit the data of the very fine instrumentation of this demonstrator: 540 data generated every second!

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Major technical progress with demonstrator SMARTHyES

22 May 2018

The SMARTHyES (SMART Hydrogen Energy Storage) demonstrator finalized by CEA-Liten and Sylfen in April 2018 incorporates three major advances in the road-map from a laboratory technology to a commercial product

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[Press Release] SYLFEN announces the first high temperature reversible electrolysis demonstrator

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Sylfen and CEA announce that they have successfully designed, assembled and tested in Grenoble in May 2018 the first functional demonstrator of the Smart Energy Hub, a solution for storing energy using hydrogen and cogeneration for buildings. This demonstrator marks a key step in the industrial recovery strategy of the French high-temperature reversible electrolysis technology.

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