Why electric cars makes sense

This article in Scientific American addresses the point that occasionally crosses my mind: if electric cars became popular, how much of a greenhouse gas benefit would be achieved when you take into account the extra electric power generation needed? Here's some good news for a change:

...a new analysis from the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) offers more good news: existing electric power plants could fuel 84 percent of "light duty" vehicles if all 220 million cars and trucks converted to electric power overnight....

The analysis noted that the capacity of the U.S. power infrastructure is underutilized. Every evening--and during days of low demand--there is a large amount of spare capacity that could easily be tapped. By charging cars and trucks with electricity at night, American drivers could reduce the nation's dependence on foreign oil while potentially cutting power prices as well. "Since gasoline consumption accounts for 73 percent of imported oil, it is intriguing to think of the trade and national security benefits if our vehicles switched from oil to electrons," notes PNNL energy researcher Rob Pratt. "Plus, since the utilities would be selling more electricity without having to build more plants or power lines, electricity prices could go down for everyone."

The researchers specifically excluded power resources such as nuclear, hydroelectric, wind and solar as each of these already produce electricity at maximum capacity. Yet, plugging in our cars could reduce U.S. greenhouse gas emissions by an average of 18 percent.