• Programme: Horizon Europe
  • Funding amount: approx. EUR 6 million, Around EUR 630,000 for Bavaria
  • Duration: 01/2024 – 12/2027
  • Coordinator: Edoardo Gino Macchi, Fondazione Bruno Kessler - FBK

EU project SMHYLES develops novel salt- and water-based hybrid energy storage systems (HESS) on an industrial scale.

One of the greatest challenges of the 21st century is the transition to climate-neutral energy sources. Here, reliable energy storage plays a key role, as production and load peaks in the electricity grid require flexible storage systems that can be used for a wide range of applications. The recently launched EU project SMHYLES aims to develop innovative, sustainable, and safe salt- and/or water-based hybrid energy storage systems. These combine two storage technologies and their respective advantages: long duration capacity and high power density. The new low-CRM (critical raw materials) systems will also contribute to Europe’s energy independence. The SMHYLES project, coordinated by the “Fondazione Bruno Kessler” (Italy), is funded by the EU under Horizon Europe with around €6 million for a period of four years from January 2024 on. The consortium includes 16 partners from seven countries.

Each storage technology has technical and economic characteristics that are ideally suited for a specific application. These characteristics include, for example, energy and power density, reaction time, environmental sustainability, and safety. Redox flow and salt batteries have a large storage capacity but can only be charged and discharged slowly. A supercapacitor, on the other hand, has fast charging times but cannot store large energy quantities over a long period of time. Only the efficient combination of both functionalities provides the necessary performance and flexibility in use.

"Modern energy storage systems need to guarantee security of supply, performance and safety, have flexible management software and be manufactured and operated in the most sustainable and environmentally friendly way possible," explains SMHYLES coordinator Edoardo G. Macchi, Head of Battery and Electrification Technologies Unit at the Fondazione Bruno Kessler in Trento, Italy.

Combining sustainable batteries with other storage systems

The central goal of the SMHYLES project is to develop and demonstrate such innovative, safe, and sustainable hybrid energy storage systems on an industrial scale. In SMHYLES, a water-based supercapacitor and, either a redox flow battery or a salt battery, are to be combined to create innovative hybrid energy storage systems.

The novel hybrid storage systems developed in SMHYLES should be able to store energy over a medium to long period of time and release it very quickly. At the same time, they will reduce the use of critical raw materials, be safe to use (as they are not easily flammable), cost-effective and recyclable. Compared to conventional solutions, these new storage systems are expected to have a 40 per cent lower carbon footprint, also thanks to novel recycling solutions, and a 20 per cent higher reliability and availability, which should make our renewables-based power grids more resilient.

Demonstrators in Portugal and Germany

The SMHYLES activities include the development, construction, deployment and demonstration of an aqueous hybrid energy storage system and a salt-based hybrid energy storage system, as well as an extension of the storage duration of an existing hybrid system. During the second half of the project, various use cases will be trialled for 12 months in the three pilot plants in Portugal and Germany:

  1. island grid (Portugal, Graciosa): Off-grid energy system with the installation of a nickel-carbon water-based supercapacitor and a salt battery supporting the island electric grid.
  2. industrial microgrid (Portugal, Maia): Further development of a vanadium redox flow battery and combination with a water-based supercapacitor, with the aim to increase the level of renewable energy source penetration in the energy mix, as well as the electric vehicle charging support.
  3. pilot plant expansion (Pfinztal, Baden-Württemberg, Germany): Capacity expansion of a redox flow battery and combination with a supercapacitor (from the EU project HyFlow) and a wind turbine; this should enable multi-day energy storage and increase grid reliability.

About the SMHYLES project

The EU project SMHYLES is developing novel salt- and water-based hybrid energy storage systems on an industrial scale. SMHYLES started in January 2024 and will run until December 2027. The project is coordinated by the Fondazione Bruno Kessler, Centre for Sustainable Energy (Italy), and is being carried out in cooperation with 15 other partners from Germany, Italy, Portugal, Switzerland, Spain, the Czech Republic, and Tunisia. The EU is funding the project under the European Framework Programme for Research and Innovation "Horizon Europe" with around €6 million.  Around 630,000 euros of this budget will be allocated to Bavarian stakeholders. From Bavaria, Landshut University of Applied Sciences (Prof Pettinger, coordinator of the EU project HyFlow, a predecessor project to SMHYLES) and the Bavarian Research Alliance are participating in the project.


During the application phase, BayFOR supported the coordinator and the consortium in the technical and content-related conceptualisation of the EU application, in the clarification of financial and administrative issues and in the formation of the consortium. BayFOR was also able to involve the coordinators of two previous EU projects (HyFlow and TwinVECTOR), which were also supported by BayFOR, in the consortium. As a funded partner in SMHYLES, BayFOR is responsible for communicating with the public and interested experts and for networking with other projects and partners.


Project coordination: Fondazione Bruno Kessler, Centre for Sustainable Energy, Italy

Project partners:
Hochschule für angewandte Wissenschaften Landshut, Germany
Fraunhofer-Institut für Chemische Technologie ICT, Germany
Bayerische Forschungsallianz GmbH, Germany   
CIRCE, Spain
SCHMID Energy Systems GmbH, Germany
C2C-NewCap, Portugal
SONICK S.p.A., Italy
Capwatt, Portugal
Capwatt Services, Portugal
Graciolica Lda., Portugal
INESC TEC, Portugal
Tomas Bata University Zlin, Czech Republic
INDRIVETEC AG, Switzerland
RINA Consulting, Italy
Comete Engineering International, Tunisia


Project coordinator Edoardo Gino Macchi

Project coordinator:
Edoardo Gino Macchi
Head of Battery and Electrification Technologies Unit – BET
Centre for Sustainable Energy – SE
Fondazione Bruno Kessler - FBK
Phone: +39 0461 314 887

Contact at BayFOR

Dr. Daniel Kießling

Dr. Daniel Kießling
Scientific Officer Information & Communication Technologies |
Engineering & Natural Sciences
Phone: +49 911 50715-920

MBA Gabriela Blumberger

MBA Gabriela Blumberger
Scientific Officer Information & Communication Technologies | Engineering & Natural Sciences and Project Manager
Phone: +49 89 9901888-132


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