Renting out your car’s battery the perfect deal?
Connect and make money. In Utrecht (The Netherlands), owners of electric cars can make an extra profit by making their car’s battery available to the electricity distributor to help stabilizing the grid. Does it pay off, Dutch newspaper, Het Financieele Dagblad, asks?
How does it work?
Park your electric car, plug it in and the network operator will take over. They’ll draw power from your car when the power demand on the network is very high and charge your battery when solar panels in the neighborhood deliver enough power.
Electrons flow back and forth, as long as you keep the plug in the charging station. This is called bi-directional charging and it works with a new charging protocol, on a larger scale than previous initiatives.
In the Netherlands the project was started by King Willem Alexander at the end of March, Renault participates and at least 145 charging points must be built.
According to Robin Berg, entrepreneur at ‘We drive solar’ and initiator of the Utrecht project, bi-directional charging can yield up to 100 euro per month for the owner of the car.
Not in cash, but the participants can charge for free in exchange. “Grid managers and energy companies are happy to pay to have a buffer, because parked electric cars are a handy way to regulate supply and demand on their network.”
“However, the car must comply with a new loading standard (ISO15118) and it only works with a handful of vehicles so far.” Volkswagen would also like to make its future (I.D.) plug-in cars suitable for this purpose.
Degrading the battery
Batteries degrade over time. We know that from smartphones and laptops. The same applies to the battery of an electric car. Each time the batteries are fully charged or discharged, some of the solvent in the battery will become mixed with other substances and the capacity will be reduced.
However, Berg believes this happens especially when you fill up the batteries 100% and empty them to the last spark. If you ‘stay in the middle’, not charging above 80% of going to low, there is less wear and tear. That’s why ‘We drive solar’ promises not to overload your battery.
90% charge can make a difference
Professor and expert in battery technology, Peter Notten of TU Eindhoven confirms. “Batteries don’t have to wear out that much, but they do because we keep charging them completely.”
The voltage in the battery is the highest at the last phase of charging, from 90% to 100%. Then temperature rises, substances start to oxidize and the decay sets in”, he explains.
Despite the remuneration of the network operator, it is not certain that the free power will outweigh the wear and tear on the battery. It remains the most expensive part (€ 10.000 to 15.000) of an electric car today.
Because the technology is still relatively new, there are not yet enough data available to be able to estimate a clear life expectancy of the battery. Another drawback is that the car will not always have full autonomy when you go for a ride that was not planned in advance.