IEA ES Task 43: Storage for renewables and flexibility through standardized use of building mass

Thermal building mass activation uses building masses to condition interior spaces, but can also function as energy storage through targeted overheating/undercooling. This storage potential can be used for local and grid-connected renewable thermal and electrical energy (Power2Heat). The project develops new content on the construction, control and business models of such storages and disseminates it as guidelines, data and on the basis of best-practice objects that have been implemented.

Short Description

The energy supply of the building sector is responsible for 33% of Austria's final energy demand and has great potential for decarbonisation. However, without suitable storage solutions, renewable energies struggle with discrepancies between availability and demand. Due to their thermal inertia, building masses in existing and new buildings already represent a significant storage potential that can be harnessed through thermal building mass activation. This IEA task was initiated in order to identify the opportunities and challenges of a broad implementation of this technology in international exchange and to develop corresponding approaches to solutions.

The central goal of the task is to make thermal building mass storage ready for a multipliable, efficient and economically attractive implementation. To this end, 4 main questions are addressed in the respective subtasks:

  1. Sustainable materials and multipliable construction techniques in new buildings and refurbishment will be investigated for their suitability for thermal component storage.
  2. Strategies for efficient system integration at building and neighbourhood level will be developed and combined with suitable control strategies for storage management and load management.
  3. Non-technical challenges and barriers for the market introduction of thermal component storage will be analysed in an international context and recommendations for action to overcome them will be developed.
  4. KPIs (key performance indicators) for thermal component storage systems will be developed in order to make systems comparable and assessable. Guidelines for the structural implementation of thermal component storage systems, including sensors, are being developed as a supplement to demonstrator fact sheets as a starting point for potential implementers.

The national partners play key roles in the task, with AEE INTEC as general Task manager and BEST as head of Subtask B. All participating Austrian institutes contribute relevant results and experience from completed or ongoing projects. The targeted results of the task are:

  • Collection of information and measurement data on successful implementation projects in Austria
  • Construction techniques and manufacturing concepts for thermal component activation in new buildings and refurbishment, including prefabricated envelope elements with different materials (e.g. wood or clay).
  • Development of prototypical system concepts and control strategies for thermal component storage at building and neighbourhood level.
  • Investigation of the influence of load management on indoor comfort and users
  • Development and investigation of new business models for energy and flexibility trading at building and neighbourhood level.

Targeted dissemination of the results will efficiently transfer information to the Austrian market, increase the international visibility of the Austrian research location and promote broad implementation of thermal component storage.


Austria (Task Manager), Denmark, Germany, Italy, Netherlands, Norway, Spain, Sweden, United Kingdom

Contact Address

Project leader

DI Christoph Rohringer
Feldgasse 19, 8200 Gleisdorf

Project partners

Dr. Daniel Muschick
BEST - Bioenergy and Sustainable Technologies GmbH
Inffeldgasse 21b 8010 Graz

DI (FH) Gerhard Hofer
e7 energy innovation & engineering
Ingenieurbüro für Energie- und Umwelttechnik
Walcherstraße 11, 1020 Wien

DI Michael Moltinger
Fachhochschule Salzburg GmbH
Campus Kuchl: Markt 136a, 5431 Kuchl