Sustainable cold and heat supply to urban areas using district cooling and district heating networks
Client Umweltbundesamt (UBA)
Duration November 2023 – March 2026
Background
Due to climate change, there is already a significant increase in average summer temperatures compared to the long-term average and an increase in the number of days with high outside temperatures of over 30°C. The burden of rising temperatures in summer is particularly noticeable in urban areas, as the higher sealing and the restriction of air circulation result in a heat island effect (urban heat island), which leads to significantly higher temperatures near the ground. As climate change increases, this effect is expected to become even more pronounced. The demand for air conditioning systems in residential buildings has increased accordingly. The need for air conditioning in non-residential buildings will also increase, not least due to occupational health and safety precautions. The energy-efficient renovation of buildings and the associated improvement of thermal insulation in summer can reduce the increasing need for cold. Overall, however, it is expected that the need and demand for active cooling for building and process air conditioning will increase.
Goals and Results
A detailed study of the existing district cooling networks and the potential, particularly with regard to an integrative development of heating and cooling networks to leverage synergies, is not yet available for Germany. Against this background, the aim of the project is to close these knowledge gaps and to show possibilities for expanding pipe-based cooling supply in conjunction with heat supply based on cooling circuits (large heat pumps). The focus is on implementing an energy-efficient and environmentally friendly expansion of cooling networks, which takes place simultaneously with the conversion of the pipe-based heat supply, taking into account the identified potential. An important basis for this project is the analysis of the current pipe-bound heat supply with heat pumps and their expansion paths. This is particularly relevant given changing conditions, as 40% of the district heating supply in 2016 was based on natural gas, the availability of which is now severely limited and must be replaced by more climate-friendly alternatives by 2045. In this context, we are also investigating how the integration of waste heat sources such as data centers and other low-calorie sources can be successfully implemented. Another focus of the study is to determine the proportion of district cooling supply in cities. Existing district cooling networks are identified and documented in order to obtain an overview of the current status and to derive potential for further expansion and new construction. In addition, it analyzes how these district cooling networks perform in terms of environmental impacts (including HFC emissions) and material consumption compared to decentralized scenarios, taking into account factors such as land use. The findings of this project should optionally be summarized in the form of a guide for municipal and private energy suppliers if the pipe-based cooling supply proves to be advantageous. This guide will contain instructions for setting up and expanding cooling networks as well as necessary prerequisites. In addition, the legal framework, obstacles and possible solutions are explained, and existing funding opportunities are described.
