HiHELIOS Second General Assembly in Ljubljana: Key Highlights

HiHELIOS is fully up and running and the partners are working hard for the implementation of the 4 use-case activities in Greece, Belgium and Norway!

On 20–21 January 2026, the second General Assembly meeting of HiHELIOS was held at the University of Ljubljana. During the meeting, project partners presented key achievements, challenges, and next steps across the technical work packages (WPs), covering the optimal design, sizing, manufacturing and assembly, and intelligent operation of the Hybrid Energy Storage System (HESS).

In addition, participants were offered a tour of the University of Ljubljana laboratories (Faculty of Mechanical Engineering), accompanied by short introductions to ongoing research activities, including hydrogen fuel cells, energy storage systems, and 3D printing applications for renewable energy system (RES) components.

Over the two-day meeting, four workshops were conducted:

1. Technical Deep Dive - an interactive session focusing on the interplay between different tools and functions for the HESS operation supported by physics-based and data-driven models. The session was led by Flanders Make

2. Exploitation Routes – a brainstorming session to refine exploitation routes for project results. Rhoe was responsible for this workshop

3. Factory Acceptance Tests (FAT), Site Acceptance Tests (SAT) definition- a collaborative session to define the protocols and metrics for FAT and SAT and performance evaluations of the HESS demonstrators. The session was led by W4E and CEA.

4. Stakeholder Engagement, Dissemination and Communication Activities -an interactive workshop to plan upcoming dissemination activities and strategize on maximizing stakeholder engagement and reach the project targets. This workshop was organized by DAFNI.

In the second day, an online session was dedicated to future members of HiHelios Stakeholder Committee. A fruitful meeting with the Greek Distribution System Operator (DSO), HEDNO, was held, during which partners discussed expectations for the Tilos use cases. The foreseen activities include:

• Installation of a behind-the-meter second-life battery at a high-load facility on the island (hotel).

• Installation of a grid-level hybrid battery system (high-energy–high-power) enabling black-start operation of the Tilos power system, thereby increasing renewable energy source (RES) penetration on the island.

Lastly, partner Energy Pool presented Morbihan Energies, a French public regional and inter-municipal cooperation body based in the Brittany region, which acts as distribution electrical grid manager of this area (contracting with the DSO) and plans the energy transition of the relevant territory. It was provided an overview of Morbihan Energies activities including infrastructure coordination, development of RES and storage projects particularly on islands, data management and consultancy services to achieve carbon neutrality.

We would like to warmly thank the University of Ljubljana for the excellent organization of the meetings and their generous hospitality.

HiHELIOS is fully up and running, with partners actively working towards the implementation of the four use-case activities in Greece, Belgium, and Norway.