Design of an obligation to use renewable energies in existing buildings for the city of Hamburg

Client: City of Hamburg

Duration April 2020 – August 2020


In order to achieve its climate targets, the City of Hamburg has decided that a mandatory quota of renewable energies will be established for the replacement of heating systems from mid-2021.
This obligation to use renewable energies in existing buildings is an effective policy instrument, which was first introduced in Baden-Württemberg in 2008 with the EWärmeG. The aim of introducing a renewable energy use obligation in Hamburg is to significantly increase the share of renewable energies in the heat supply and the energy efficiency of existing buildings in Hamburg and to rapidly expand the technologies required for this.

Projects goals and results

The aim of the study is the analysis of different heat supply systems that fulfil the obligation to use renewable energies in existing buildings. With a view to the status quo in Hamburg as well as the foreseeable future development of the energetic condition of buildings, the fuel prices and, if applicable, the innovations to be expected, requirements and options for action for the fulfilment of the obligation are to be derived from an energy-economic, heat-strategic and socially acceptable point of view.

Tasks of IREES

  • In this project, IREES is responsible for the definition and economic analysis of possible decentralized renewable heat supply systems.

Project partner

  • Öko-Institut – Coordinator


Dr. Jan Steinbach
Dr. Jan Steinbach