Electric Cars, Then and Now

January 22, 2008

On Jan. 15, I posted a blog about Toyota's and GM's announcement to offer electric hybrid cars for sale by 2010. Reader "AnneA" posted the comment/question below.

I wonder what the differences are between this "plug-in" and the electric car from the mid 1990's, the GM EV1.  After seeing the documentary "Who Killed The Electric Car", I must say that I'm skeptical about how this will play out, although I'd love to be wrong. [annea]

Good question. Reader "Mysterymeat" replied with a brief explanation, but I wanted to go deeper. So I called up Tony Markel, a senior engineer and hybrid electric car expert at the National Renewable Energy Laboratory in Golden, CO. Here's the gist of what he said:

The first generation EV1 had a lead-acid battery. But it was heavy, not very efficient, and could only hold enough charge to take the car about 80 miles or so.

The second generation EV1 (above) had a nickel-metal-hydride battery. It was lighter and more efficient than the lead acid, but could only hold enough charge to take a car about 100 to 120 miles. (For a copy of the specs, down this PDF.)

Now, even though the average American doesn't drive more than 100 miles per day, he or she still gets "range anxiety," said Markel, which is why the hybrid electric cars being developed today are more attractive to consumers.

Unlike the EV1, which was all electric, hybrid electric cars use a combination of electricity and gas to make the engine run efficiently, use less gas, and offer long range driving when needed.

As Mysterymeat pointed out, some hybrid electric cars can be plugged in to recharge the battery (they're called PHEVs). Other hybrid electric cars do not have to be plugged in (they're called HEVs).

The battery on a HEV (also made from nickel-metal-hydride) gets charged while the car is being driven. This means that, ultimately, you need gas in the tank in order to get the battery charged.

I like the idea of PHEVs best. They also need gas in the tank, but you can recharge the battery (also nickel-metal-hydride) much more cheaply by plugging it in. You generate fewer emissions this way, too.

What's more, cars that plug into an electrical socket could lead to a vehicle-to-grid system that's attractive to consumers and utility companies. With this system, batteries from electric cars would be used collectively to store and release excess power from utility companies that normally fluctuates throughout the day. "One interesting statistic," said Markel, "is that a typical vehicle is used only 5 percent of the day for driving. The rest of the time it’s parked."

Parking lots full of cars-as-electricity-sponges would also help utility companies incorporate renewable yet ofttimes fickle energy sources, such as solar and wind, into their power generation models.

You can read more here about a vehicle-to-grid plan. And just yesterday, the NY Times published an article about a project in Israel to sell electric car transportation similar to the way cell phones are sold. (See my blog about this here.)

Comments

[Annea]

Wow . . . "Parking lots full of cars-as-electricity-sponges". After reading that a typical vehicle is used only 5% of the day for driving and parked the rest of the day, it seems like such a no-brainer.