Heat pumps, PV systems, storage and e-mobility offer technical possibilities and potentials on a local level. In the opening speech, Christof Wittwer (Fraunhofer ISE) and Fabian Zuber (Reiner Lemoine Stiftung) emphasized the importance of on-site supply in the course of the transformation of the energy system.

What are the potentials of on-site supply from scientific perspectives?

Researchers from Fraunhofer ISE, Reiner Lemoine Institute and Reiner Lemoine Foundation gave impulses for this. Christoph Kost (Fraunhofer ISE) explained the relevance of prosumers for on-site supply based on the study »Potentials and framework conditions for the expansion of prosuming«. Among other things, the contribution of PV prosumer solutions in multi-family buildings to energy sharing concepts for the economic viability of decentralized supply was explained.

The study »Quartiers im klimaneutralen Stromsystem« (Neighborhoods in a climate-neutral power system), which was conducted by researchers led by Editha Kötter at the Reiner Lemoine Institute, focused on determining the impact of different heat pump-based heat supply concepts on the grid expansion requirements in common distribution grid types. For this purpose, 5 neighborhood concepts for heat supply as well as 4 common distribution network types were selected and network analysis was performed. The result: at just under €2,000, the network expansion costs per converted residential unit in the network area are low. However, current regulations need to be adapted to enable economically viable neighborhood concepts.

Matthias Kühnbach (Fraunhofer ISE) addressed the research questions: whether operational management without a central authority leads to higher self-sufficiency within communities as a whole, and what contribution bidirectional charging of electric vehicles makes. His findings: Interaction of energy agents leads to increased use of community-generated electricity, and this effect is amplified by bidirectional charging. Thus, energy agents represent valid complementary design to centralized neighborhood management.

Philipp Blechinger (Reiner Lemoine Foundation) gave an overview of on-site supply at international level. International experience shows that renewable on-site supply is possible. New approaches such as decentralized energy cells, smart meters, storage and smart control allow optimization at the local level.

On-site supply in the political debate

In the subsequent session of political discussion, experts exchanged views on on-site supply from the perspective of citizen energy, neighborhoods, municipal utilities and energy companies. This included topics such as acceptance and grid fees. For Harald Uphoff (Bündnis Bürgerenergie), it is important to motivate people to participate in the energy transition. Susanne Schmelcher (dena) saw the energy transition as a bottom-up process and decentralized plants should play a major role in an overall systemic view. Jürgen Weigt (VKU) identified acceptance and getting people on board as one of the biggest success factors of an example project in which a CO₂ saving of 70 % was achieved by using rooftop PV systems, heat pumps and hot water tanks. Bernhard Strohmayer (bne) reiterated the need to bring new possibilities of on-site concepts into the discourse and to provide appropriate solutions.   

Finally, Daniela Fietze (Stiftung Umweltenergierecht) concluded how the scientific findings on on-site concepts can arrive in the regulatory process.

At CINES, we deal with the topic of on-site supply. Here you can download our new study »On-site systems as a flexible building block in the energy system - A cross-sectoral potential analysis« (in German). Learn more about our work in the field of on-site supply here. Contact us or write to us.