Load Flexibilization in Buildings

Lastflexibilisierung von Gebäuden
© Fraunhofer ISE
Laboratory building at the Fraunhofer ISE campus in Freiburg. The building has a 500m³ cold water storage tank, which can be used both as a cold storage or source for a heat pump and for load shifting.

Due to the increasing shares of electricity generation from fluctuating renewable sources, the question arises which role buildings play in the interaction with the power grid and which potentials a grid-serving operation has for the integration of renewable energy, for the relief of the supply grids or for the development of economic incentives.

Here, the use of the building mass as thermal storage, the dimensioning and use of additional thermal storage, the variable use of plant technology (e.g. through fuel switch) and building operation (demand side management) are considered. In the past, numerous projects in this field have analyzed the potentials of grid-serving operation of buildings and developed evaluation methods for this purpose, which have also been taken up in the international discourse (e.g. via EBC Annex 67 on Energy Flexible Buildings). We develop model-predictive control strategies for plant optimization (e.g. for grid-serving operation of buildings) and test them in simulation environments as well as by means of hardware-in-the-loop and in demonstration buildings.

Our R&D services in detail:

  • Creation and comparison of operation control strategies
  • Optimized control strategies integrating external signals (price, weather, share of RE)
  • Development of model predictive control concepts
  • Hardware-in-the-loop tests of plants under consideration of grid-serving operation strategies

Selected Research Projects


Grid-Supportive Operating Strategies for Efficient Heating and Cooling of Buildings in the Trade, Commerce and Services (TCS) Sector


Demonstration of Flexibility Options in the Building Sector and their Interaction with the Energy System in Germany