SONOMA COUNTY, CA – Fleet Manager Dave Head said that the County of Sonoma has converted a 2008 Toyota Hybrid Prius to a plug-in hybrid electric vehicle (PHEV).

The plug-in hybrid has the potential of getting more than 100 miles per gallon of gas and further reducing vehicle emission levels by as much as 50 percent. Currently, the County is on track to operate more than 240 hybrid fleet vehicles by 2010 as a means to meet self-imposed greenhouse gas emission reduction targets.

The plug-in hybrid conversion by the Fleet Operations Division is designed to explore the benefits of using advanced battery/hybrid technology in the County fleet.

The conversion process includes the addition of a secondary Lithium-ion battery pack installed where the spare tire is normally located. The system uses state-of-the-art computer software and controls that are integrated into the existing conventional hybrid electric vehicle to provide additional all electric mode driving capabilities. The vehicle operates on battery power alone at lower speeds and automatically switches to the vehicle’s conventional hybrid/electric system when the battery runs low or under heavy loads.

When operated on battery power alone, the converted Prius has a range of 30-35 miles between charges. When driven using the combination of both the conventional gas-electric hybrid and the all-electric mode, mileage will double when compared to a standard Toyota Hybrid Prius. The County’s fleet of conventional Priuses currently averages 45 mpg, so an improved rating of 90+ mpg can be expected with this latest generation of PHEV technology. To charge the secondary battery pack, the vehicle is plugged into an ordinary 110 volt standard household outlet for approximately six hours.

The County currently has one charging station at its administration center in Santa Rosa, but efforts are underway on initiatives to install additional stations for use by PHEVs as well as electric vehicles. With the expanded number of PHEV’s in its fleet, and the expected introduction of total electric vehicles in the near future, the County will be engaged in helping to develop a network of charging stations around Sonoma County.

The converted Prius will be tested in a number of County applications, and expansion of the program will be considered based on the test data collected. It is very likely that additional vehicles will be added to the test group and as PHEVs become commercially available from original car manufacturers (projected for 2010); the County will transition from converting existing vehicles to purchasing direct from the manufactures.

There are now 152 hybrid/electric vehicles in active use that have driven more than 2 million miles for the County, and the 2008-2009 hybrid fleet is expected to add another 1.25 million miles to this total. This translates to a fuel savings of around 30,000 gallons of gasoline and a reduction in greenhouse gases of over 300 tons from the hybrid fleet.