The 3E Multiple Dwelling Unit

Electric mobility may contribute to the Energy Transition if solutions for the charging of electric vehicles with renewable energy may be found, thus rendering the operation of electric vehicles CO2-free. At the same time, the self-generation of electricity with photovoltaics in private household is more and more economic and thus attractive for consumers. Already, the majority of new photovoltaic installations today are intended for private consumption, thus opening promising perspectives for the future combination of self-generated energy and electric mobility. In addition, the system electric vehicle, charging infrastructure and electricity grid may be enhanced by local micro cogeneration plants.

The 3E-MDU project carries out the first field test of a decentralised energy system for self-generation of electricity and heat combined with electric mobility, piloting the scheme in three multiple dwelling units with a number of tenants. Both photovoltaic installations and combined heat and power generation by ‘home plants’ (mini cogeneration units) with integrated heat storage are included. Moreover, a stationary battery storage is installed in addition to the battery in the electric vehicle.

The overall system is connected to energy trade markets via the IT platform Schwarm-Dirigent managed by the project partner LichtBlick. Thus, electricity from the photovoltaic installation, the mini-CHP and the batteries fed into the grid is marketed with maximum energy economy. Moreover, the use of additional electricity from the grid is optimised considering energy-economic criteria.

The analysis of the results of the field test will provide an assessment of the technological, ecological and energy-economic aspects of the decentralised energy system of the 3E-MDU. In addition, previously unknown requirements for the charge of vehicle batteries participating in city district car sharing and the control of stationary energy storage are part of the analysis.

The ifeu provides the life cycle assessment of the system. Furthermore, the relevance of the proposed solution for the current and future building stock is part of the investigation. Further questions address the applicability of the system to single family homes and the energy-economic role of the proposed concept in future energy systems.


January 2014 – May 2017


Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety


Lichtblick SE (Project coordinator)


The 3E Multiple Dwelling Unit (in German, pdf 1,92 MB)

The 3E Multiple Dwelling Unit - Final Report (in German, pdf 5,09 MB)

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