The BMW Group is currently testing a novel charging strategy for electric vehicles that primarily charges when there is sufficient green power available on the grid.
If we want to combat climate change, we will have to rely less and less on fossil fuels and instead move towards solar and wind power in particular. We have known this for some time now but the technical barriers to putting this into practice are often greater than we anticipated. One example of this would be electricity grids. While power plants up until now have generally generated electricity centrally, from where it is then distributed to households, there are now thousands and thousands of decentralised photovoltaic panels and wind turbines helping to produce electricity. And, at certain times, the amount of power produced by these units fluctuates a great deal. During very sunny and/or windy periods, there is plenty of electricity available. But there are phases when the amount of green power produced in one region is so minimal that huge volumes of electricity sometimes have to be sourced from another region to make up for the shortfall.
Germany is a good example of this, where the south increasingly often has sufficient green power derived from hydroelectricity and a growing percentage of solar power. But the supply of wind power from the north of the country also plays an important role. It is transmitted via special power lines to consumers in the south. But a big problem associated with those top-ups is the limited capacity of the “power autobahn”.
But what if electric vehicles could be so intelligently “refuelled” with primarily green power that their batteries were only charged when there were no grid bottlenecks? That would allow – thanks to the growing number of electric vehicles – an increasing amount of power to be sourced at the very time when there was sufficient power available from sustainable sources and plenty of capacity along the power autobahn, which would take the pressure off the grid. What’s more, the “reserve power plants” operating only in the event of bottlenecks would have to generate less electricity too. That would help combat climate change, because those power stations are generally coal or gas-fired plants.
This is precisely the idea behind a pilot project launched by the BMW Group and European transmission system operator TenneT. The basic premise of the experts is that it is often not crucial when exactly an electric vehicle like a BMW i3 charged. It only has to be to “full” when the driver wants to use the car. So it would make sense for a BMW i3 to primarily draw electricity only when sufficient green power is available and there are no grid bottlenecks.
Naturally, the consent of the driver would be required in each case, and this would only work if the vehicle did not need to be charged to full battery capacity as quickly as possible. So the mobility needs of customers would always take priority here. But anyone with an EV whose lifestyle could cope with time-flexible charging could support the optimal use of energy from renewable sources by taking up this option. And in future it is even conceivable that customers could, for instance, benefit from reduced prices for off-peak charging times.
The kernel of this concept is a charging management system specially developed for BMW and the kind of networking technology that is already a standard feature of vehicles like the BMW i3. The charging management system registers the current grid demand signalled by transmission operator TenneT and uses that as the basis for timing the charging sessions of any networked EVs in the optimal way. And that works irrespective of whether the vehicle is connected via a public charging station, a BMW wall box or a conventional household power point.
The project launched in Germany late last year, based on a comparable pilot in California, is the first such trial to be conducted in Europe. In California, the BMW Group has been testing smart, demand-driven, grid-related control of charging sessions on more than 300 electric vehicles for several years now, with great success.