Science Forums 2

[C1ay]

First consider the fact that there are power grids now that suffer rolling blackouts during peak usage times as a result of overwhelming demand. These grids are already short of capacity and loading them with the local transportation loads would simply add to that problem.

Secondly lets play with a little math to get us in the ball park. For the sake of easy computing let's assume the average fill up of gasoline is around 10 gallons. Let's also assume that by converting to electric we can gain an increase in efficiency that would allows us to fill up with only 40% of that figure since combustion engines are considerable less efficient than electrical propulsion systems. That brings our fill up equivalent to 4 gallons of gas.

Various sources on the internet give an equivalency of 120,000,000 joules to 130,000,000 joules of energy per gallon of gasoline, an average of 125,000,000 joules. That 500,000,000 joules per fill up.

Now suppose 10 minutes is a reasonable amount of time for someone to pull into the station and pump 500,000,000 joules of power into their vehicle. At 600 seconds that's around 833,333 watts per second or 3,000,000 kwh per vehicle to fill up. Multiply that by the number of cars per day filling up at a station and you'll get an idea of the power requirements.

These numbers get better of course if you allow an hour for a fill up or you build in enough capacity that cars only charge at night but I don't currently think the grids are even sufficient for that.