| Is this strategy still going to work if everyone is doing the same thing? My local supermarket has a couple of electric car charging points, amongst perhaps 200+ car parking spaces. On a busy saturday most of those spaces are full. Certainly it's possible to install a charging point at every parking space, but it requires both a large scale building project to lay all those wires (the existing charge points are right by the supermarket - where the power is already available), and also potentially an upgrade to the local power network. If each of those cars is fast charging at 50 kW, the supermarket carpark will suddenly be consuming 10 MW. Assuming a constant cycle of people, that's equivalent to the average power usage of 20,000 houses. Just in one supermarket car park. Fortunately it's unlikely everyone will charge every time they pop in, but it's something that has to be considered carefully. The electric grid has to be sized for peak load - most of the time it's not near capacity. If we're going to slot electric cars into the existing grid we have to manage demand very carefully - which means only charging cars when electricity supply is high or demand is low. Everyone rapid charging whenever they feel like it (eg during the Saturday shop) will cause huge stability issues. The most straightforward way to manage it is to try to get as many cars as possible charging overnight (or charging whenever they're idle) and then manage when they actually draw power centrally based on electricity supply. That means extensive kerb side charging points. |