About the company

Startup or self-employed

Members type

38000 Grenoble, France

Company size

Nicolas Bardi / Caroline Rozain



  • Affordable and clean energy

  • Sustainable cities and communities



Alliance member


Smart Energy Hub: hybrid energy storage solution for self-sufficient and carbon-free energy buildings.

Established in 2015, Sylfen develops Smart Energy Hubs, a hybrid energy storage solution combined with real-time energy management software that ensure or reinforce energy autonomy and flexibility for self-sufficiency and carbon-free energy buildings and eco-districts. These hubs allow both (i) storing excess renewable energy for several days or weeks, and (ii) covering electricity and heating needs even in periods of high demand or low renewable energy production. Only hub reversibility and flexibility are able to provide an answer to create a largely decarbonated solution based on local energy sources. For owners of buildings, the advantages of the solution proposed by Sylfen include: • the reduction and control of energy costs, the new energy mix of intermittent energy + hybrid storage + natural gas CHP allowed by Sylfen being at parity or cheaper than the electrical grid rates; being based on mainly Capex and maintenance cost, it is decreasing with passing years contrarily to the grid prices; • an outstanding reduction of CO2 emissions (up to -70% compared to electric grid) and primary energy use (down to 25 kWh/m²/y), making it possible to reach the most advanced standards for sustainable buildings and near zero energy districts which is a key value for players who engage on social and environmental responsibility; • a patrimonial added value on the real-estate that will comply with future standards thus avoiding accelerated depreciation; • the securing of electricity supplying areas where the electrical network is insufficient –there are many of these, even in developed countries; At the heart of this product, Sylfen implements the Solid Oxide Cells (rSOC) technology, benefiting from 12 years of R&D at CEA-Liten, 40 million euros and 22 patents granted, whose successful implementation on a pilot plant in 2014 was a worldwide record performance in electrolysis. This breakthrough technology operates in a reversible manner, either as an electrolyser or as a fuel cell: it stores electrical energy in the form of hydrogen obtained from the electrolysis of water and co-generates electricity and heat in the fuel cell mode (the fuel is primarily stored hydrogen but can also be biomethane or natural gas). This technology is packaged with (i) 200 bars hydrogen storage units (ii) Li-ion batteries covering peak power needs and (iii) a proprietary software tailor-made and operate the energy management according to the customer’s specific needs. A 1-10 kW proof of concept prototype of the Smart Energy Hub operates in Grenoble, demonstrating the full integration of all the above-mentioned subsystems and an automatic flexible operation among all possible energy storage and supply modes. A first contract is signed to deliver a 3-modules 120 kW unit in Turin (Italy) in 2019.

Company Sylfen

Labelled solution

Hybrid energy storage for autonomous buildings

The Smart Energy Hub is an innovative hydrogen-based energy storage solution for NZEB (Net Zero Energy Building) to reach self-efficiency.
Solution Label February 2019 Solution