INDHEAP Workshop in Graz

May 21, 2026

Hybrid Solar Systems for Industrial Process Heat & Power — From Concepts to Implementation

On 14 April 2026, the INDHEAP project hosted the workshop “Hybrid Solar Systems for Industrial Process Heat & Power: From Concepts to Implementation” in Graz, Austria, at the Grand Hotel Wiesler, in connection with the 4th International Sustainable Energy Conference (ISEC 2026). The workshop featured contributions from the SOLINDARITY project and gathered stakeholders working on practical solutions for the decarbonisation of industrial heat.

With strong interest from industry and the research community, the event provided a space to exchange on hybrid solar concepts, medium-temperature thermal energy storage, design methodologies and tools, and the pathway from pilot projects to wider deployment.

Why this workshop?

Decarbonising industry requires solutions that are not only technically sound, but also reliable, cost-effective, and adaptable to real industrial constraints, especially for mid-temperature heat applications. Hybrid configurations combining solar thermal, PV, thermal energy storage, and auxiliary technologies can help address these needs, but successful implementation depends on good system design, integration approaches, and learnings from demonstration activities.

The workshop was designed to:

  • Present concepts, design methods, guidelines, and tools developed in INDHEAP and SOLINDARITY
  • Share testing and demonstration insights
  • Provide an overview of medium-temperature heat storage technologies for industrial applications
  • Foster exchange between projects, technology providers, and industrial stakeholders

Target audience

The workshop welcomed industrial end-users (including energy managers, plant operators, and decision-makers), technology providers and system integrators, partners from the INDHEAP and SOLINDARITY projects, as well as experts from related initiatives and ISEC 2026 participants with an interest in industrial heat decarbonisation.

Participation

The workshop reached full capacity, with just over 50 participants attending in person. Attendees represented a mix of industry, research organisations, technology suppliers, and associations, with active engagement across sessions and networking.

Final agenda at a glance

The workshop followed a compact yet high‑impact programme, combining technical insights, project experiences, and interactive discussion over the course of the afternoon.

It began with Session 1, which set the scene by exploring Hybrid Solar Thermal Systems for Industrial Process Heat & Power: Overview. This opening session brought together experts from INDHEAP and SOLINDARITY to present key system concepts, integration approaches, and early insights from testing and demonstration activities. Contributions from Wolfgang Gruber‑Glatzl (AEE-INTEC) and Valéry Vuillerme (CEA-Liten) for INDHEAP, alongside Panteleimon Tzouganakis (CERTH) and Varshil Dalal (DRL) for SOLINDARITY, provided a well-rounded introduction to the state of the art.

The programme then moved to Session 2, focusing on Medium‑Temperature Heat Storage Technologies for Industry. This session offered a deeper look at storage solutions as a key enabler of hybrid solar systems, highlighting their role in improving flexibility and performance. Research insights from Arnaud Bruch (CEA), Robert Haberl (OST), and Gerald Zotter (AEE INTEC, IEA ES Task 44) showcased current developments and practical applications.

Following a short networking break, the workshop continued with Session 3, dedicated to the Optimal Design of Hybrid Solar Thermal Systems for Industrial Heat and Power. Here, the emphasis shifted toward the practical implementation of hybrid solutions, with presentations on design methodologies, modelling tools, and integration strategies. Contributions from Valéry Vuillerme (CEA-Liten), Rene Baumann (AEE-INTEC), Dimitris Papageorgiou (TVP Solar), and Varshil Dalal (DRL) illustrated how project results can support real-world system optimisation.

The technical programme concluded with an engaging panel discussion, “From pilot to scale: Can hybrid solar systems meet industrial heat and power demands?”. Bringing together perspectives from across the sector, the panel featured Leopoldo Mico (European Heat Pump Association – EHPA), Lucia Torlai (Solar Heat Europe – SHE), and Dimitris Papageorgiou (TVP Solar).

The afternoon closed with a networking session, giving participants the opportunity to continue discussions, exchange perspectives, and build connections.

Key outcomes and takeaways

Across the afternoon, discussions reflected a growing interest in hybrid solar solutions as a pathway for decarbonising industrial heat. Participants highlighted the relevance of these systems particularly for low‑to‑mid temperature applications, which represent a significant share of industrial heat demand, suggesting strong potential for sectors such as food, textiles, and pharmaceuticals.

A central theme throughout the panel discussions was the complementarity of technologies. Rather than competing solutions, solar thermal, PV, thermal energy storage, and auxiliary technologies such as heat pumps were consistently presented as part of a balanced, integrated system. Each plays a distinct role — from generating renewable heat, to ensuring operational flexibility, to supporting system performance and temperature levels.

The workshop also highlighted that successful implementation goes beyond technology alone. The sessions on design tools and methodologies demonstrated the importance of practical frameworks to support real‑world decision-making. At the same time, participants stressed the need to increase familiarisation among industrial end-users and to develop more real-world projects to build confidence and experience.

Discussions also pointed to remaining barriers to scale-up, including system integration challenges, investment risks, and the need for stronger regulatory clarity and business cases. Speakers also highlighted the importance of policy support for renewable heating and cooling, as well as the need to align incentives to accelerate industrial uptake.

Finally, the workshop reinforced the importance of collaboration across the value chain. Exchanges between technology providers, industry, research organisations, and associations were seen as essential to align perspectives and support the transition from pilot projects toward scalable and replicable industrial solution

What’s next?

INDHEAP and SOLINDARITY will continue disseminating results, tools, and learnings from demonstrations and system development activities. Follow-up exchanges initiated during the workshop will help strengthen collaboration and support a pathway from successful pilots toward replicable industrial solutions.

Stay connected

To follow the progress of both projects and remain informed about upcoming events, results, and publications, we invite you to:

Explore our work:

  • INDHEAP: https://indheap.eu
  • SOLINDARITY: https://www.solindarity.eu