There are a few things you should know about charging e-vehicles. Firstly, an e-car does not need to be charged that often. At least not if the vehicle is driven like its combustion engine counterparts. In metropolitan regions, that's an average of just 22 kilometers a day. In small towns and villages, cars travel an average of 44 km per day. But even that is not enough to drain a battery. Secondly, if everyone charges at the same time, for example from 6 p.m. onwards, when people arrive home after work, there could well be bottlenecks in the power grid. Could! But it doesn't have to! This is exactly where grid-optimized charging comes into play. Grid-optimised charging means that an e-vehicle is connected to its wallbox as normal after work, but the electricity only flows when the grid is ready and not in the red zone at its load limit.
In order to guarantee perfection, it would make sense if, in the future, the car, wallbox and grid could communicate with each other as a matter of course. Technically, this would also be possible via so-called smart meter gateways. Smart meter gateway sounds complicated, but it is nothing more than an intelligent measurement and control device that enables smarter grid control than a blown fuse. However, grid operators, wallbox producers and car manufacturers are not yet working together as intensively as they perhaps should be when it comes to smart meter gateways. For example, charging profiles still cannot be read automatically from all e-vehicles. And the current method of collecting grid status data means that a grid operator only knows that a fuse has blown somewhere. Where exactly this happened, he is usually still in the dark for a while.
The possibility of switching off consumers on the grid side in the case of an overload of the electricity grid is also technically possible and is already being practiced today, especially with large industrial customers - keyword load shedding. However, if one day hundreds of thousands of e-vehicles are connected to the grid, smart meter gateways will have to be used much more closely than is the case today. The fact that we at eeMobility can already enable grid-optimized charging today is, by the way, due to a small detour that we take when collecting data for our charging profiles. These can also be created on the basis of fluctuations on the electricity price exchange. If the demand for electricity is low or the supply of electricity is particularly high, the price falls. If demand is high or the supply of electricity is low, the price rises.
Based on the price barometer of the electricity price exchange, it is thus possible to decide when charging e-vehicles could lead to grid bottlenecks and when not. All of this even works without expensive grid expansion. Nevertheless, our power grids will have to become more intelligent in the future. After all, the safe charging of electric vehicles is only the first step towards a sustainable energy transition. The second step will be to be able to discharge e-vehicles intelligently so that they can be used as energy suppliers. After all, a fully charged car battery contains enough electricity to supply a single-family household for a week.