May 31, 2010

STILL NOT READY FOR PRIME TIME? An electric-car quick-charge test drive:

Their dream may be a good one. But it’s also problematic. There were, after all, five i-Mievs on this drive that needed charging, and with only one charger it didn’t take 20 minutes to fuel them. It took about an hour and a half.

Mitsubishi didn’t leave us to cool our heels during that charging, but took us to a nice lunch. Imagine how nasty the scene could get if five i-Miev owners showed up at one charger with the fifth in line finding out he’s going to be spending more than an hour cooling his heels at Sonic. So what if he has a coupon that gets him two milk shakes for the price of one?

A modest, average size gas station has, say, eight pumps. And usually those pumps push fuel at a rate of between five- and ten-gallons per minute. Going on the low end of the scale, lets say it takes three minutes to fuel up an average car with a 15-gallon tank. So in an hour, that eight-pump station could theoretically fuel 160 average cars from empty to full.

In contrast, a station with eight Eaton/TEPCO Quick Chargers could theoretically fuel just 24 i-Mievs to 80-percent full in an hour. To match the capacity of a modest gas station, completely filling 160 i-Mievs to 100-percent of battery capacity (on 25 minute charges) in one hour, would take at least 67 Quick Chargers with one parking space for each charger. Figure 300-square feet of space for each charger and parking spot and that’s a half acre of land before accounting for driveways or other infrastructure.

Ouch.