With multiple mentions at this week’s Democratic presidential convention, public awareness of plug-in hybrid vehicles can only continue to grow. So Toyota’s announcement that it will speed up a previously announced program to offer limited numbers of Prius
hybrids that can use grid electricity to recharge a larger battery pack is significant.

Toyota president Katsuaki Watanabe told reporters in Tokyo yesterday that fleet tests of an experimental Prius, modified to be rechargeable, will be moved up to late next year from 2010. According to a Toyota spokesman in the States, the cars will go first to “non-consumer fleets” like electric utilities—a traditional test bed for experimental electric vehicles.

The plug-in Prius will use lithium ion batteries, which hold more energy than the current Prius’s nickel metal hydride cells. But the next model of the Prius hybrid, which will be unveiled next January as a 2010 model, will use an improved nickel metal hydride battery pack—meaning its electric-only range will still be limited to a couple of miles at best. The plug-in Prius adaptation may run electrically as far as 10 miles, but that’s still a fraction of the 40 miles Chevrolet promises for the Volt, which is slated for introduction in late 2010.

GM is starting to more sharply highlight the technology difference between those two cars. Last week, the company’s product czar, Bob Lutz, told reporters at a press event that the Volt “wasn’t even comparable” to a Prius converted to plug into the electric grid.