The findings of a very interesting study have just been released that works on the assumption that by 2025, one quarter of US cars will be plug in hybrid vehicles (PHEVs). Assuming continued growth in population and vehicle ownership in America, that amounts to at least 60 million vehicles, up from - I would guesstimate - a few dozen today.

The Oak Ridge National Laboratory Study was principally concerned with what the impact would be on electricity demand. As per their press release;

"In an analysis of the potential impacts of plug-in hybrid electric vehicles projected for 2020 and 2030 in 13 regions of the United States, ORNL researchers explored their potential effect on electricity demand, supply, infrastructure, prices and associated emission levels. Electricity requirements for hybrids used a projection of 25 percent market penetration of hybrid