PG&E offered ride-alongs in its VTrux from VIA. In Cupertino, the truck powered the public-address equipment for the stage as well as a vendor booth, demonstrating the vehicle’s exportable power capacity.

The first-generation trucks have 15-kilowatt capacity, roughly the equivalent of a generator for a small or medium house; that amount could increase in future models. Ultimately, the trucks could act as backup power sources to shorten planned or unplanned outages and boost the electric grid when needed.

With a 402 hp (300 kW) electric motor and lithium-ion batteries, the vehicles have an electric range of up to 40 miles. The gasoline engine extends the range to 350 more miles.

PG&E’s transportation fleet includes 3,100 alternative-fuel and high-efficiency vehicles, including compressed natural gas, bio-diesel, electric and hybrid units.

PG&E joined with VIA Motors in 2008 to develop the extended-range electric vehicle, or eREV. Last year, PG&E tested two eREV trucks as part of the utility’s overall electric utility fleet. Based on the positive results of that test, PG&E received the first pre-production models of the VTrux this month, with full-production models available in early 2013.

Pacific Gas and Electric Company, a subsidiary of PG&E Corporation, is one of the largest combined natural gas and electric utilities in the United States, servicing 15 million people in Northern and Central California.