PowerFlex – integrating the heating and cooling sector into the electricity market model PowerFlex

In the project PowerFlex the ISOE investigates the spread and usage of air conditioning units in private households in Germany. Based on this, the extent of future energy consumption is going to be modeled to achieve a more precise estimate.


So far, air-conditioning of private homes is uncommon in Germany, as opposed to southern European countries or the United States. However, a growing interest in their usage on the part of private households can be witnessed. At the moment, approximately 750,000 air-conditioning units are installed in private households in Germany. In addition, there are a large number of mobile air conditioners on which there is no current data. To date, reliable data on the spread and usage of air-conditioning and their power consumption are not available. As a result, the influence of increased air-conditioning on the power consumption of private households is unknown. The aim of the project is to establish a reliable and meaningful database as is needed for balancing and modeling energy consumption in the so called cooling sector. A central goal of the project Powerflex, therefore, is to determine the number, the installed performance and the mode of operation of air-conditioners in private households in Germany.

Research approach

ISOE carries out an empirical investigation on the air-conditioning of residential buildings. On the basis of the insights gained, a more precise model of the energy consumption of private households for air-conditioning will be developed and future developments will be estimated. The research team will also investigate which factors influence the purchase and use of air-conditioning units by private households in Germany. It is probable, that the spread of air-conditioners is influenced by decreasing acquisition costs, higher income of private households and increased availability. But behavioural science approaches show that these influence factors do not suffice to explain the purchase and use of air-conditioning units.

Therefore, the results of the empirical investigation carried out by ISOE deliver important insights into the interplay of climatic, technical and economic influences with social and socio-cultural factors with respect to the purchase and use of air-conditioners in Germany. These results will allow for a better estimate of the dynamics of the usage behavior of private households, which will be integrated into the PowerFlex electricity market modelling carried out by the Oeko-Institute. The model considers the flexibility of electricity supply and demand. It calculates how power plants, storage options and appliances with a flexible electricity demand (e.g. cold storage houses, electric vehicles) should operate to reduce costs and CO2emissions. Moreover, the results will be made available to science and policy by means of publications.

Cooperation partners

  • Oeko-Institute e.V. Freiburg 
  • ForWind – Center for Wind Energy Research 


The German Federal Ministry for Economic Affairs and Energy (BMWi) is funding the project “Integration of the heating and cooling sector into the electricity market model PowerFlex for analysis of cross-sectoral effects on climate protection goals and renewable energy integration“.


Koch, Matthias/Tilman Hesse/Tanja Kenkmann/Veit Bürger/Markus Haller/Christoph Heinemann/Moritz Vogel/Dierk Bauknecht/Franzsika Flachsbarth/Christian Winger/Damian Wimmer/Lothar Rausch/Hauke Hermann/Immanuel Stieß/Barbara Birzle-Harder/Michael Kunkis/Jens Tambke (2017): Einbindung des Wärme- und Kältesektors in das Strommarktmodell PowerFlex zur Analyse sektorübergreifender Effekte auf Klimaschutzziele und EE-Integration. Freiburg: Öko-Insitut


2014/08 – 2016/12