Bidirectional Charging (Vehicle-to-Home) in Home Energy Management Systems: Exploring Potentials with a Simulation Tool

The home will become the most important link between heat, electricity and mobility. For instance, the concept of Vehicle-to-Home (V2H) allows to use the average long parking times of electric vehicles for energy management applications in the household. In this study, we focus on developing a simulation model in the Home Energy Management System (HEMS) to explore the impact of bidirectional charging on household energy supply. Bidirectional charging allows electric vehicles not only to take energy but also to feed energy back to supply other consumers. The study addresses the following research question:

What is the potential for increasing self-sufficiency through bidirectional charging in a modern single-family house with HEMS assets?

First of all, bidirectional charging was researched in initial pilot projects, and the findings were used to validate the results. Furthermore, load profiles for household loads, heat loads (heat pumps) and production profiles (photovoltaics) were collected. Based on the findings from the literature, a simulation model was developed that considers the dynamic interactions between the electric vehicle and the system components in the household.

Different scenarios of bidirectional charging could be simulated and compared e.g. with a unidirectional system. In addition, different parameters could be adapted and analyzed through a sensitivity analysis. Parameters of photovoltaic power, orientation of the photovoltaic system, capacity of vehicle battery and home storage, as well as daily consumption by kilometers driven were varied.

The results of the simulations show that bidirectional charging has the potential to increase the self-sufficiency of renewable energy (in this case photovoltaics) in the household, to reduce electricity costs and indirectly to reduce the load from the energy grid. It is important to say that the potential strongly depends on individual user behavior, photovoltaic power and the presence of the vehicle on site.

This study contributes to the scientific literature by presenting a simulation model for bidirectional charging in HEMS. The results provide important insights for households and the simulation model can be a decision support tool for the choice and sizing of system components in the HEMS. In addition, the study provides input for further research and development in the field of electromobility and home energy management systems.