Power for electric vehicle has so far often flowed in one direction—from the charging device to the vehicle but this will soon change with vehicle-to-grid (V2G, vehicle-to-grid) applications.
An immersive pilot test jointly carried out by Porsche, grid operator TransnetBW, and consultancy Intelligent Energy System Services (IE2S) confirms that electricity can be stored in high-voltage batteries in smart electric vehicles to achieve power balance. During the pilot test, five production Taycan models were connected to the grid in a home environment and laboratory state through Porsche Home Energy Management (HEM). Porsche Engineering experts calibrate the control center software in advance to ensure compliance with actual test conditions.
As renewable energy sources increase, balancing electricity in the future will become more important for stabilizing grid operations. The reason for this is, even if wind and solar power cannot consistently generate electricity, the grid must remain consistently stable. If the power grid cannot maintain a stable frequency of 50 Hz, there will be a risk of power outages.
Today, traditional power plants have been responsible for moderating fluctuations. Using a high-voltage battery as a buffer can lead to a win-win situation: EV owners can be compensated for balancing power.
▲Porsche Tests Electricity Recharge Efficiency
In the future, when electric vehicles are idle, they will also be able to send electricity back to the public grid to become a mobile power plant and help to achieve so-called balanced power-balancing power fluctuations.
The key element of data transmission in the pilot test is the cloud-sharing system developed by IE2S, which converts the grid operator's balance power set point into a vehicle-specific signal to adjust and control electric vehicle charging in real time. The shared system can also control high frequency synchronous bidirectional data transmission. For testing, the shared system was linked to TransnetBW's main control center in Wendlingen, near Stuttgart.
Dr Rainer Pflaum, Chief Financial Officer of TransnetBW, explained: "A truly measurable milestone: the project team has been able to apply a complex communications infrastructure in the control system and multiple electric workshops, while meeting stringent specifications for balanced power storage and supply. This will allow us to integrate electric vehicles into the smart grid of the future. "
For safety reasons, power balancing is based on strict German standards. During the pilot test, detailed measurement data showed that the target values of the grid control system were reached and can be applied to primary (frequency containment reserve, FCR) and secondary (automatic frequency restoration reserve, aFRR) to balance power. Rapid stabilization of the grid must rely on FCR, whereas aFRR takes five minutes to fully stabilize. Relevant measurements are made in control systems, assets such as Taycan models, home chargers and home energy management systems, and shared systems. For FCR, home energy management system functionality is extended to include local frequency measurements.
Of course, V2G (Vehicle-to-Grid) is not Porsche's creation. When there was a power outage in Texas last year, some car owners used F-150 gasoline batteries to supply electricity for home use. Taiwanese electric scooter Gogoro also demonstrated the technology of using power swap stations to recharge the public grid. These new technologies used to provide grid balance are not only the driving force for the popularization of electric vehicles but also an important foundation for the development of renewable energy.
(Image: Porsche Taiwan)
