The phrase “game-changing” gets tossed around a bit too much, but if there’s any trend in the EV world that deserves that description, it’s bidirectional charging, which promises to allow EV batteries to be used not only to provide backup power for buildings, but also to earn revenue by delivering services to the electrical grid.
Above: Porsche testing vehicle-to-grid applications with its all-electric Taycan (Source: Porsche)
Porsche has partnered with German grid operator TransnetBW to conduct “a realistic pilot test” to demonstrate that “electrical balancing power can be stored in the high-voltage batteries of an intelligent swarm of electric cars.”
Five production Porsche Taycans were connected to the power grid via the Porsche Home Energy Manager (HEM) both in a domestic environment and under laboratory conditions.
The Porsche Home Energy Manager monitors energy and power consumption and enables the use of smart charging functions.
“The charging technology of the Porsche Taycan and our Home Energy Manager and Mobile Charger products have a lot of potential for the future: the pilot test proved that. And the balancing power market isn’t the only thing a pooling system of this kind can be used for,” says Lutz Meschke, Deputy Chairman of Porsche’s Executive Board. “Advanced solutions for green charging and other vehicle-to-grid applications are also conceivable.”
As more renewable energy comes online, balancing power will become even more important for secure grid operation. Power grids must be stabilized at a constant AC frequency (60 Hertz in the US, 50 Hz in Europe), and fossil fuel power plants are typically used to even out any fluctuations. “Using high-voltage batteries as a buffer would be a win-win situation,” says Porsche. “Drivers of electric cars could be financially compensated for their contribution to balancing power.”
The key element of the data communication used in the pilot test is a cloud-based pooling system that coordinates and controls the charging processes of the EVs in real time, by translating the grid operator’s balancing power setpoints into vehicle-specific signals. In order to test it, the pooling system was connected to TransnetBW’s main control center near Stuttgart.
“A real measurable milestone: the project team has managed to implement the complex communication infrastructure between our control system and several electric vehicles,” explains TransnetBW CFO Dr. Rainer Pflaum. “At the same time, the strict specifications for storing and supplying balancing power have been met. This will enable us to integrate electromobility into the intelligent power grid of the future.”