Audi e-tron: How to prevent blackouts with grid-optimized charging
Sceptics of electric mobility imagine a world where several electric cars are charging at the same time, causing the streets to go dark with regular blackouts. Audi has begun a small-scale test, hoping to offer a clear answer to the sceptics, an Intelligent and grid-optimized charging strategy that will relieve the grid demonstrating to the wider public the advantages of electric mobility. Audi says its "e-tron models and the charging system connect are already prepared and ready".
Audi collaborated with GISA and other partners to simulate an overload scenario in the local power grid: multiple electric cars charging simultaneously and high power on the street supplied by a local network transformer.
What is known as grid-optimized charging is designed to counteract this scenario through the intelligent management of charging procedures and thereby prevent a grid overload. The charging procedure's dynamic management is achieved through targeted communication between the electric car and the grid operator. In practice, this will mean delayed charging, taking into account the desired time of departure and the actual load in the power grid. At the end of the day, the test shows a win-win situation: The electric car uses downtime to fully charge with dynamic charging capacity adjustment while also relieving the power grid without restricting the customers' mobility needs. This is made possible by new modules in the domestic power grid that allows the house, the electric car, and the power grid to speak the same language.
Digital power connection: the SMGW
The central component is what is known as a smart meter gateway (SMGW) – a device that is already mandatory today if a household's power consumption exceeds 6,000 kWh per year. The SMGW establishes a highly secure data connection between the house and the grid operator via a certified IT backend. All necessary information and control signals are transmitted in a targeted manner – either to the home energy management system (HEMS) or directly to the charging system connect that Audi offers as an option.
This allows the charging capacity of the Audi e-tron or Audi e-tron Sportback to be reduced as required – up to 11 kW as standard and by up to 22 kW upon request. Both models are equipped with the necessary intelligence, and Audi intends to provide its future electric models with this ability as well.
Outlook: individual charging management for each car
The new networking technology will allow the charging capacity, charging time, and charging duration to be controlled for each car in the medium term. Besides, some attractive prospects may arise: A customer who can charge their Audi e-tron at work could accept certain limitations while charging at home, for example. In return, they would obtain the power from their provider at a discounted price.
Intelligent charging of electric cars is an important element of the sustainable energy industry of the future. Provided that use is made of the potential, it may also be possible to use electric cars as flexible storage devices for solar and wind power – a resource with very inconsistent availability. AUDI AG has set itself ambitious targets on the way to emissions-free mobility: The company is working on making its vehicle fleet CO2-neutral by 2050. To achieve this aim, Audi is pursuing a broad electric offensive that involves launching around 20 fully electric models by 2025.
Connectivity: participants of the energy industry speak a common language
The technical standards and communication protocols necessary for grid-optimized charging have already been drawn up. The new DKE application rule AR-E 2829-6, which describes the exchange of information between the domestic grid connection and the energy industry, is the main guideline. The EEBUS data model serves as the communication protocol. It was developed by the EEBUS e.V. initiative in which Audi is involved as well. It aims to connect the participants of the future energy industry in Europe based on a common language.
Research project: four strong partners for Audi
Audi worked with highly specialized partners on the pilot project in Chemnitz and contributed its extensive expertise in electric mobility and charging infrastructure. IT service provider GISA GmbH functioned as the initiator of the project and administrator of the SMGW. Robotron Datenbank-Software GmbH provided the software for the backend. KEO GmbH developed the software for the communication interface of the SMGW. EMH metering GmbH & Co KG provided the hardware for the intelligent measuring system.