Exergetic Assessment of Municipal Energy Systems

GHG reduction targets were fixed at 80 % by 2050 compared to 1990 as part of the current energy concept of the German federal government. How drastic the changes will be by 2050 is shown in the WWF report "Model Germany". It is assumed that the heating demand of a building in 2050 will be on average 10 to 15 kWh/m2a. By then all buildings will be at the passive house standard. Similar changes are needed in the industrial sector. Questions remain about what direction the energy system of the future will take as well as its technical and economic feasibility. Here municipalities are faced with challenges since the changes must be initiated and implemented locally. These changes will affect residents, businesses, public institutions and public utilities, and will require the development of future businesses.

In Germany there are already advanced municipalities that have been actively promoting climate protection for some time. Many of the activities are related to the 2020 emission reduction targets. The long term view of climate protection objectives has recently been becoming of more interest especially the appropriate perspective of what measures would be needed to achieve the ambitious CO2 neutrality goals by 2050. In addition to the smaller municipalities that may have a renewable energy surplus, cities and urban areas are increasingly in the spotlight.

It is clear to most municipal decision makers that energy conservation, cogeneration and renewable energy needs to be supported. There are large uncertainties though about how to address the change of energy systems and how to adapt to the ever decreasing energy needs. To answer these questions, the exergy of an energy flow is increasingly being used as an evaluation criteria along with the overall energy efficiency and greenhouse gas reduction. The exergy analysis indentifies not only the amount of energy flows but also their quality (as an expression of a systems working capacity). This project will analyze how local energy systems and energy collection systems in the future be optimized exergetically and in terms of CO2 reduction.

The aim of the project is to develop proposals and possibilities in which the energy system of the future can be sustainable at the local level. The energy efficiency and the exergetic optimization of the system are in the forefront alongside the CO2 neutrality of the system. The study focuses on the local heat and power system on both the supply and consumption sides.


December 2010 – May 2014


German Federal Environmental Agency (Umweltbundesamt)


Fraunhofer Institute for Building Physics (IBP), Kassel

Richtvert | Energiesystemberatung, Münster


The results of the project are available for download on the homepage of the German Federal Environment Agency (in German)

For an overview of the project see the slides presented in 2014 at the Kommunale Klimaschutzkonferenz (Municipal Climate Protection Conference) in Lübeck (in German)

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