Fourth generation district heating – Feasibility study for a district heating network 4.0 in Rosenheim, Germany

Feasibility studies for the implementation of innovative heating network systems are funded within the framework of the funding call "Fourth generation district heating" of the Federal Ministry of Economics and Export Control (BAFA). After the successful application for the funding, FfE and Stadtwerke Rosenheim are carrying out a feasibility study for the transformation of an existing heating network into a heating network 4.0.

Within the scope of the feasibility study, various innovative concepts for the provision of heat are compared technically and economically. The aim is to develop a concept with which at least 50 % of the heat demand can be provided by renewable energies, of which a maximum of 50 % is allowed to be provided by biomass. In addition, the energy supply should be efficient and contain forward-looking components such an intelligent sector coupling and a monitoring concept.

What is a heating network 4.0?

A district heating network 4.0 is a heat network that distributes the heat at temperatures of 20 - 95 °C in a highly efficient way. This heat is primarily supplied from renewable energies and waste heat. In addition, monitoring is carried out for these networks, which enables the identification of losses and intelligent sector coupling. The term "fourth generation district heating" is intended to express that, from the first generation, the temperature levels of heat supply as well as its efficiency and the share of renewable heat sources have changed in several development steps.

What is intelligent sector coupling?

In contrast to the simple coupling of the energy supply sectors, intelligent sector coupling is a coupling that makes it possible to use the flexibility of one supply sector in a supportive way for the other. In the case of electricity-heat coupling, one example is the heat-controlled operation of a heat pump. From the point of view of the overall system, the direct operation of heat pumps at time of heat demand does not necessarily make sense. In the case of a grid-guided mode of operation, heat pumps are switched on and the connected heat storage tanks are filled when the electricity supply is high (e. g. by photovoltaics). In the case of critically high loads in the electricity grid, on the other hand, the buffer in the heat storage tank is used up before the heat pumps switch on. The aim of this regulation is to use available renewable electricity.