Bidirectional Charging in an Industrial Park – Ten Use Cases from the Bid-E-V Project
First steps of the overall project
In the first few months of the “Bidirectional electric vans” (Bid-E-V) project, use cases for the integration of bidirectionally chargeable electric vans were developed. These are to be simulated in the further stages of the project and partially implemented in practice during a field test.
The use cases were developed together with the project partners in interactive workshops and then documented in standardized profiles and e3 value models. The aim was not only to harmonize the wishes and planned projects of the various project partners, but also to define the scope of the individual applications.
Methodology for developing the use cases
The use case methodology, which has been tried and tested in several projects at the FfE, was used to develop the use cases. This serves to consolidate different interests in projects with many different stakeholders and to shape the joint project. In contrast to previous FfE projects, a special feature of the Bid-E-V project was that the use cases for controlled charging took place in a commercial environment.
Regardless of the use cases implemented, the commercial context results in a significantly higher number of parties and commercial relationships involved compared to private single-family homes, which inevitably makes the use cases more complex.
The use cases developed were therefore divided into two categories: Real estate use cases and energy industry use cases.
The real estate use cases focus primarily on the implementation of the field test at the test site. Various design variants of the ownership structure of vehicles and interfaces within the property were discussed.
The energy industry use cases primarily concern the interaction of the property with the overall system (market and grid), such as the optimization of self-consumption, emissions and remuneration as well as requirements in accordance with § 14 EnWG and measures to stabilize the system.
Different property structures can be combined with energy industry use cases as required, resulting in many possible constructs.
Results
The results of the use case development are described below.
Property use cases
The property scenario for the field test envisages a logistics company acting as a fleet manager and managing its vehicle fleet with the Mercedes Me app. The employed drivers also use the Mercedes Me app and can charge their vehicles at the property manager’s charging stations. A price table with various charging tariffs provided in advance by the CPO takes into account the energy industry use cases developed.
Energy business use cases
The following ten energy industry use cases with different focuses were developed by the project consortium:
You will find a detailed description of all use cases in the download area. To give you an insight, we would now like to present three selected examples:
Spot market-optimized charging
The property manager receives information on the day-ahead and intra-day prices via the energy management system (EMS). The fleet manager then optimizes the charging plans and transmits them to the EMS. The property manager takes care of the purchase and sale of electricity. The fleet manager uses the bidirectional charging function of the vehicles to feed electricity into the property or the grid when electricity prices are high and receive compensation for this.
CO2-optimized charging
The CO2 values of the electricity mix are integrated into the EMS. The fleet manager controls the charging processes of the vehicles in coordination with the EMS so that electricity with the lowest possible CO2 footprint is used. The CO2 optimization is based on the local grid balance, the quarter-hourly CO2 balance of the exchange electricity and the German CO2 balance (e.g. CO2 monitor).
Reactive power supply
The EMS of the property manager transmits the information about the available reactive power flexibility of the vehicle fleet to the flexibility aggregator. The latter can submit a bid on the reactive power market via a corresponding platform of the distribution system operator (DSO) or transmission system operator (TSO). In order for the flexibility or reactive power provided to be called up, it must first be released by the DSO. This ensures that calling up the reactive power does not lead to bottlenecks in the distribution grid. When the DSO or TSO requests the reactive power, the flexibility aggregator forwards the signal to the fleet manager via the EMS. The fleet manager is remunerated for providing the reactive power at the price offered. The aggregator receives a pro rata remuneration from the revenue for its service.
Local grid service in accordance with § 14a EnWG (controlling intervention by grid operator)
On the basis of § 14a EnWG, the distribution system operator (DSO) can send a signal to the property manager’s energy management system (EMS) to reduce the load if there is a risk of grid overload. The property manager uses the EMS to control which load at the site is to be reduced and receives a reduced grid fee for this. The subscriber reports the actual load consumed to the DSO via a smart meter gateway (SMGW). The aim of this use case is to smooth the load profile at the transformer and thus minimize the expansion of the distribution grid.
These examples provide an initial overview of the diversity of use cases. For detailed information on all use cases, please download the complete documentation from our download area.
The next steps
For the further progress of the project, the development of the necessary components is now planned in order to successfully implement the developed use cases and achieve optimal results. Simultaneously, interested and suitable pilot customers will be acquired who are willing to participate in the field test and provide valuable practical insights.
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