C/sells - The energy system of the future in the "solar arch" in southern Germany

The digitalization and increasingly interconnected infrastructure of the energy system has become one of the major drivers, alongside the continuing expansion of renewable energy generation, of the changes currently affecting all aspects of the energy sector and the actors within it. The C/sells project will put this decentralized, digitalized version of the Energiewende to the test with a slew of groundbreaking projects, all united by three guiding principles: Cellularity, Participation, and Diversity.

The role of the FfE in C/sells

In C/sells the FfE is exploring the challenges and opportunities created by a digitalized energy system, with a particular focus on research in the following areas:

Logo Csells

C/sells brings together more than 60 research institutes, energy suppliers, network operators, consultants, and technology firms as partners in a joint project designed to demonstrate the energy system of the future in a test region spanning Bavaria, Baden-Württemberg, and Hesse. Over four years, this project will show firsthand how intelligent energy supply can succeed. More than 30 demonstration cells will host highly-visible pilot projects, in addition to intensive citizen participation campaigns in nine participation cells.

You can find more detailed information about all aspects of the C/sells project here.


C/sells is part of the Federal Ministry of Economy and Energy’s funding program “Smart Energy Showcases – Digital Agenda for the Energy Transition” (SINTEG). The goal of SINTEG is the development and exhibition of solutions that enable and encourage the sustainable, reliable, and affordable supply of energy featuring high proportions of renewable energy. After being demonstrated in pioneer regions across Germany these solutions should also be able to be scaled up for wide-scale use. At the core of the plan is the intelligent interconnection of generation and consumption of energy, driven by the use of innovative new network technologies and business models. Successful solutions developed during the project will serve as examples to base future systems on.

In addition to the research areas described above, the FfE serves as the C/sells regional coordinator for Bavaria, and as a subcontractor in the Intelligent Heating for Munich project led by the Stadtwerke München.

Incentives & Goals

The increasing market penetration of electric automobiles and electric heating in homes and businesses has combined with continued expansion of decentralized renewable energy generation, placing new and larger burdens on local electric grids. Both of these trends are expected by many to continue at increased rates. One potential solution is decentralized flexibility – combining the local or regional potential of a multitude of smart devices, all with the ability to adjust their energy use, in order to relieve stress on the grid.

Additionally, a potential analysis and the development of new methods for the use of flexibility options in the context of the larger power system will help optimize the integration of renewable energy into the system. This will take the form of the conception and deployment of a flexibility platform in Altdorf, a partner cell in eastern Bavaria.

The development of methodical approaches within the scope of the project will assist the search for answers to, among many others, the following guiding questions:

  • How can digitalized energy infrastructure be used to enable the realization of a solar-centric/solar-dominated energy system within the context of the Energiewende?
  • How can flexibility be tapped to enable the integration of renewable energy sources into the grid, and what would the value of this be for the distribution network operators?
  • Which concepts and methods will prove themselves in practice and can offer a blueprint for widespread use?


Research Topics





    (Basic data and flexibility potential)
Icon Flexibilität   

Quantifying the regional potential of flexibility represents an essential research topic, to be tackled by multiple teams at the FfE. While one group will conduct load-flow studies with the FfE tool Gridsim to determine the current flexibility needs of the distribution network, another will determine the extent to which flexibility options can assist with optimizing network operations.

In order to provide a solid foundation of data to place and appraise flexibility within the distribution network, further highly detailed datasets will be added to the regionalized energy system modelling tool developed by the FfE, FREM. Further data collected will be used to improve the prediction and aggregation functions of the model.


Definition und Kategorisierung von Flexibilitätsbegriffen

Figure 1: Definition and categorization of flexibility terms




    (Strenghtening the grid through flexibility)
Icon Flexplattformen  

In order to harness the potential of different flexibility options a Flex-Platform will be developed and tested Altdorf, a partner cell in eastern Bavaria. The main goal of the platform is to create new market structures that bring together network operators and the wide variety of flexibility suppliers, with a focus on their potential to relieve grid congestion. In addition to conceptualizing and implementing a flexibility platform in cooperation with other key stakeholders, the requirements of a flexibility platform will also be studied from techno-economic and legal-regulatory points of view.


e3 Flex Plattformen

Figure 2: Smart market platforms in C/sell

Further information can be found in the Concept Paper of the Altdorf Flex-Market.


Konzeptpapier des Altdorfer FlexmarktsAbbildung 3: Concept Paper of the Altdorf Flex-Market


Demonstration and Field Trial of the Altdorf Flex-Market

    (including subject concept)
Icon Demonstration und Feldversuch  

The academic observation of the rollout of smart grid components in the region of Altdorf bei Landshut continues to provide insights regarding the added value of smart/interconnected infrastructure for the provision of electricity. Even more importantly, these technologies are the foundation upon which the design of the Altdorf Flex-Market is based. 30-60 households, public institutions, and businesses will be recruited as test subjects for the Altdorf Flex-Market, which was conceptualized by the FfE and implemented in cooperation with Bayernwerk, and given the opportunity to market their flexible facilities to the grid operator in order to avoid grid bottlenecks. Scientific studies assessing public acceptance of the digitalization of the energy system will also be conducted in concert with this field trial, particularly to appraise the influence active participation by citizens has on their acceptance of digitalization.


Grafik Flyer ALF

Figure 4: ALF flyer for the field test in Altdorf


Grafik Interview

Figure 5: Interview with the FfE C/sells team on the field test in Altdorf


Foto Altdorf1 Foto Altdorf2

Figure 6: Impressions from the project region in Altdorf near Landshut


System-Scale Effects

    (Effects on the energy system, e.g. avoidance of grid bottlenecks; Holistic assessments, e.g. sustainability of digitalized energy infrastructure)
Icon Systemrueckwirkungen  

Digitalized infrastructure and the changes accompanying the digitalization process will fundamentally change the energy system as we know it. This module will study, among other things, how so-called “Prosumer-Cells” (used to model flexibility platforms) behave in the context of the larger system. ISAaR, the energy system modelling tool developed by the FfE, will be vital in this process. Additionally, the consequences resulting from the implementation of the smart grid infrastructure required for the flexibility platform will be analyzed. Effects on sustainability, both ecological and in terms of the resilience of the energy system, is one such key research area.

Grafik Marktdesigns

Figure 7: Market designs to be investigated



Recommended Courses of Action

Icon Handlungsempfehlungen  

To ensure that useful insights gleaned from C/sells can be put into practice by stakeholders, even while the project is still active, a variety of stakeholder-specific manuals will be produced that address challenges of digitalization and present recommended courses of actions to move forwards towards the digital and sustainable energy system of the future.

Smart Meter 1 SmartMeter2

Figure 8: Publication Smart Meter - Environment, Technology, Added Value



Figure 9: C/sells-internal recipe for the use case methodology





Figure 10: Project profile of the FfE-activities in C/sells


Further Information:


Funding and Partners


The research activities described here will be conducted by the Forschungsstelle für Energiewirtschaft e.V. and the Forschungsgesellschaft für Energiewirtschaft mbH as part of the joint project C/sells. These activities are funded by the German Federal Ministry of Economy and Energy (BMWi) as part of the funding program “Smart Energy Showcases – Digital Agenda for the Energy Transition” (SINTEG – funding code: 03SIN121).

In addition to the BMWi, Bayernwerk AG, Intel Deutschland GmbH, and the Stadtwerke Augsburg Netze GmbH also provide the FfE with financial support, data, and valuable insight from industry experts. Furthermore, these key partners will evaluate the results of the various projects and the potential for application in their respective services areas.


bayernwerk intel swa 
Download this file (20170307_Project-overview_FfE_Csells_eng.pdf)project overview291 kB
Cookies make it easier for us to provide you with our services. With the usage of our services you permit us to use cookies.
To learn more about our data privacy commitment, please refer to our Privacy Policy.