Successful Completion of the Harmon-E Cluster: Recommendations for Integrating Electromobility into the Energy System

The increasing electrification of the transportation sector represents one of the most significant challenges for the future energy transition. In particular, integrating battery-electric vehicles into the existing power grid requires intelligent, flexible, and, above all, interoperable solutions to efficiently incorporate electromobility into the energy system while ensuring grid stability and security.  

The Harmon-E cluster, a subproject of the research initiative unIT-e² has identified key areas and solutions to address challenges of electric vehicle integration. These aim to enable sustainable, grid-friendly, and market-oriented integration of electromobility into the energy system. 

Key Insights and Recommendations

Standardization and Interoperability  

Unified standards such as ISO 15118-20 and EEBUS facilitate communication between vehicles, charging infrastructure, home energy management systems, intelligent metering systems (iMSys), and grid operators. These standards improve interoperability and minimize technical errors. Regular, practice-oriented test events refine standards by addressing interpretative ambiguities and fostering cross-industry collaboration.  

Grid-Friendly Control  

The control of small-scale flexibilities under §14a Energy Industry Act was successfully demonstrated in field trials using iMSys infrastructure. Neither grid-friendly control nor combining it with market optimization caused restrictions for participating users.  

Accelerating iMSys Rollout and Integration of Small-Scale Flexibilities  

To utilize small-scale flexibilities, such as those from electric vehicles, the rollout of iMSys should be accelerated and simplified, and standardized installation and commissioning processes should be implemented. Digital tools and unified portals for registering and managing devices can support this process.  

User Acceptance Through Experience  

Positive user experiences are critical for acceptance and trust in connected e-mobility solutions. Accessible, professional informational materials are essential for educating and informing potential users.  

Regulatory Adjustments  

The legal framework for Vehicle-to-Grid (V2G) applications should be simplified. Barriers, such as double charges, should be removed to enhance the economic feasibility of innovative system solutions.  

Enhancing Grid Congestion Management  

Grid operators cannot currently utilize small-scale flexibilities, including electric vehicles, for congestion management. It is recommended to use unutilized flexibility potential, not covered by the existing cost-based redispatch, through a complementary hybrid redispatch model.  

IT Security  

Security mechanisms, such as TLS and Public-Key Infrastructures (PKIs), should be mandatory in protocols to prevent attacks on the infrastructure.  

Field Trials as a Basis for Innovative Solutions

Extensive field trials tested various use cases for intelligent charging of electric vehicles:  

• Private Households  

Two local grids near Oldenburg were equipped with modern measurement technology and smart meter gateways to test grid-friendly and market-oriented charging in 19 single-family homes.  

• Workplace 

At the Essen (Oldenburg) site of food manufacturer Wernsing Feinkost GmbH, grid-friendly and market-oriented charging was tested with a fleet of electric vehicles.  

• Smart Homes 

Residents of a newly built single-family house near Bremen tested various use cases, including a heat pump, photovoltaic (PV) system, home battery storage, and electric vehicle integration with an intelligent metering system (iMSys) and a home energy management system. 

• Laboratory Tests  

Bidirectional charging of electric vehicles was investigated in two laboratory setups in Stuttgart. The tests included ISO 15118-20 communication between electric vehicles and wall boxes, the integration and connection of additional technical components (home battery storage, iMSys with control unit, home energy management system, solar inverter, PV emulator, Charging Station Management System, aggregation and trading platform), and grid feed-in (Vehicle-to-Grid).  

Project Partners in the Harmon-E Cluster

The partners of the Harmon-E cluster – Compleo Charging Solutions AG, EEBus Initiative e.V., EWE Netz GmbH, EWE Go GmbH, Fraunhofer SIT, FfE, KOSTAL Industrie Elektrik GmbH, Mercedes-Benz AG, PPC AG, TenneT TSO GmbH, The Mobility House GmbH, University of Passau, Viessmann Holding International GmbH – jointly developed key solutions for the sustainable use of electromobility as part of a future energy system.