Solar thermal energy and heat storage

Three quarters of the energy consumed by residential buildings in Switzerland is used for heating, and one quarter for electricity. Industry also has high thermal energy requirements for space heating, cooling, water heating and process heat at moderate temperatures. The SFOE research programme ‘Solar thermal energy and heat storage’ focuses on this dominant segment of energy consumption and supports research and development into technologically and economically promising solutions for the collection, storage and use of solar heat. Our research focuses on optimising components and system concepts, networking (sector coupling) different renewable energy sources, and scaling and establishing heat storage as a central element for a resilient energy supply.

Current research priorities

Thermal solar collectors

Planning and operational optimisation of large collector fields for integration into heating networks and process heating applications
Technical innovations in the field of thermal and PVT collectors

Heat storage

Technical challenges in the implementation of storage systems such as pits, caverns, aquifers, geothermal probes or other large-scale thermal storage systems
Increasing storage density, reducing energy and exergy losses, application-specific optimisation of heat exchangers
Strategic importance of storage in the energy system and in particular in decarbonised, purely renewable energy systems
Reliable planning, as well as social, financing and operating concepts for large-scale projects

Systems

Compact, intelligent, sector-coupled solar thermal and heat storage solutions for individual buildings and local energy networks
Optimised storage design depending on renewable sources and consumer profiles, predictive control strategies if necessary
Detection of malfunctions and solar thermal performance optimisation

Planning tools

High-performance analytical models for simulating storage stratification, including charging and discharging devices based on the heat conduction equation
GIS-supported storage and energy planning

Project submissions

Typically every two years (2025, 2027, etc.), the Solar Thermal Energy and Heat Storage programme launches calls for proposals on current research priorities (see “Documents”).
Bottom-up project submissions in the research priority areas listed here are possible at any time in the Solar Thermal Energy and Heat Storage programme.

Publications and student research projects

All publications of interim and final reports on the research work can be found on ARAMIS (see also “Links”).
Further publications appear in relevant scientific journals, conference proceedings or publicly available fact sheets on various topics.
As part of research projects, the participating colleges and universities regularly award bachelor's, master's and doctoral theses and ensure that the findings of the research are communicated to a wide audience through lectures and seminars.

Documents
Links

Call for projects "Challenges in the realisation of large-scale thermal storage and large collector fields"

Key topics:
• Technical challenges for the realisation of large-scale thermal storage
• Connection of renewables and waste heat sources to large-scale thermal storage
• Improving the framework conditions for large heat storage projects
• Challenges in the planning of large collector fields
Applications can be submitted by 23.05.2025.