The Sacramento Municipal Utility District, an agency that many young kids grow up dreaming about working for someday, is testing out a plug-in hybrid crafted by Valence Technology and Energy CS. The car is a 2005 Toyota Prius that contains a lithium-ion auto battery from Valence that essentially lets the car run mostly on electricity. The battery gets recharged through a wall socket.
Plug-ins get about 100 miles to the gallon, although the cost of the additional battery makes them a tough sell, concede plug-in proponents. The range is also limited, but that's not a big deal for fleet cars at government agencies. Energy CS and academics at UC Davis have turned SUVs (see photo) and Priuses into plug-ins.
Typical hybrids do not plug into the wall.
Plug-ins pollute less than ordinary hybrids, but it depends where you recharge. In Ohio, where a lot of electricity is generated by coal-burning plants, the emissions reduction achieved by driving a plug-in is pretty minimal.
SMUD has driven the car about 1,000 miles and will come out with more data in the relatively near future. They plan to test the car for two to three years.