This field test examined the technology of bi-directional charging, with which a car can both charge and supply power back to the electricity grid or, in this case, your home.
Using your car as a battery to power your home. BMW and Eneco eMobility have taken the next step to make this innovation accessible to everyone. This field test examined the technology of bi-directional charging, with which a car can both charge and supply power back to the electricity grid or, in this case, your home. The test is part of a larger international project through which BMW conducts early research into the entire bi-directional charging ecosystem and what it can mean for the customer.
BMW supplied a specially adapted BMW i3 and charging station, while Eneco eMobility installed and tested the technical installation at a customer's home. The electric driver could immediately use the BMW car battery as an energy buffer. The test showed that the fully charged battery of the BMW i3 (with a net capacity of 37,9 kWh) can supply a house with energy for two days, assuming an average use of 11 kWh per day. And then you also have power left for a short ride. By charging when the electricity is relatively cheap and using it when the electricity is more expensive, you can save up to 850 euros per year with bi-directional charging.
This technology is not only beneficial for your wallet. Because you can time your consumption, the climate can also benefit from it. By charging the battery as much as possible with renewable sources, for example when the sun is shining or when there is a strong wind, you can reduce or even avoid the use of fossil-generated electricity.
Energy efficiency.
An existing bottleneck in this way of electricity storage is the loss of efficiency. Practice shows that there is an average efficiency of about 90%. This means that every time you charge or discharge your car, some energy is lost in the exchange with the house or the grid. This is unavoidable and depends on the components chosen in the car and the charger. A positive first result is that the efficiency of the test set-up is above the average of 90%.
Answering questions.
Customers of BMW and Eneco eMobility are certainly open to using this technology, but they also have questions. For example, what are the effects of bi-directional charging on the car battery? These effects are currently being researched extensively in the market. And with this application, is the car sufficiently charged for scheduled trips the following day? Smart apps, such as the MyBMW app and the Eneco Smart Charging app, offer a good solution for this. All in all, it is up to providers to address these questions in order to give electric drivers the confidence to make the switch to bi-directional charging. And for policymakers there is also work to be done from a fiscal point of view. This takes time. The field test is another step forward in this process. With promising results.
