While the German "Energiewende" has thus far focused on the electricity sector and the Renewable Energy Act (EEG), the importance of other sectors, such as the heat supply, will also be incorporated into the energy transition in the near future. A local heat distribution network has the potential to cover the demand of multiple consumers with a single system. In a low temperature network, a heating medium temperature range of 30 to 40 degrees Celsius is sufficient, representing an opportunity for supplying the necessary heat from renewable energy sources such as geothermal and solar thermal, and for utilising seasonal heat storage systems. Such integrated, smart heating concepts are highly efficient, able to cover a large share of year-round heating demand through seasonal storage systems, and employ a high share of various renewable energy sources and waste heat from industrial processes. They are referred to as fourth generation district heating (4GDH). However, 4GDH has seen limited adoption in Germany. In order to promote these systems, the German Federal Ministry for Economic Affairs and Energy (BMWi) commissioned a brief study on pilot projects for renewable energies in highly efficient low-temperature local heat distribution networks with seasonal storage capacities.
adelphi participated in the development and design of this study as part of a larger consortium consisting of Ecofys, Prognos, PricewaterhouseCoopers (PwC), the Renewable Energy Agency (AEE), the German Energy Agency (dena), and the Institute for Energy and Environmental Research (ifeu) in Heidelberg. The study defined the necessary minimum technical requirements, as well as examine the cost reduction potentials for individual components and overall heating systems. Various funding programmes and incentive schemes were benchmarked. adelphi's specific tasks included the identification of advantages and disadvantages of different support approaches, the barriers to implementation of innovative heating systems, as well as the preparation of a feasibility study. For this purpose, adelphi assessed the costs of such systems, conduct a profitability assessment, and quantify the potential for expansion of these systems, including associated production costs.