Bi-directional charging, how does it work?
Large batteries, such as those used in e-cars, can also be used outside the e-car. Instead of sucking up electricity, battery electric vehicles (BEV) could also feed electricity back into the grid. This is called bi-directional charging. Because once the energy has been charged into a battery, it can also flow out of it again.
e-car as Mobile Hub
With bidirectional charging, the e-car can be used as a stationary or mobile energy hub. Overnight, when a community needs little electricity, the electric vehicle charges its battery from the grid. The next day it might be not driven at all or only for a short distance. In this case, it can feed part of the charged electricity back into the grid when it is most needed, during the day. That makes the e-car an actual energy hub that can charge and store electricity, consume it or – possibly for a fee – feed it into the public grid again.
Pioner Energy Hub in Switzerlnd
A first broad application of the energy hub idea is being implemented in Switzerland. Honda, Mobility, and V2X Suisse are working on a joint project. The small Honda model e has the technical possibility of bidirectional charging. One single Honda e can return up to 20 kilowatts of electricity to the grid when connected to a bi-directional charging station. Altogether, fifty vehicles of the model mentioned are now to be used temporarily as electricity suppliers in the country.
In the near future, electric cars will not only take electricity from the grid. They will become a new way of transporting electric energy. Since bi-directional charging allows the battery of the vehicle not only to use the charge for the motors but also allows it to charge other cars and discharge to storage systems at homes or businesses.
Inspired by article on nzz.ch
Read about The Second Life of Batteries and why A Charging Station at Home is Crucial.
