On the topic of plug-in vehicles, Ward showed a healthy dose of skepticism. According to Ward, in spite of studies showing that 70 percent of commutes are less than 40 miles per day, having plug-ins with a range of only 40 miles would only cover about 35 percent of total miles traveled. The energy required to charge plug-in vehicles also poses problems. Plug-in proponents point to most vehicles being plugged in at night and taking advantage of off-peak generation and lower costs. Ward told his audience that a study of night time generation indicates that the vast majority of it comes from coal fired power plants. Until carbon sequestration becomes mainstream at power plants the use of coal generated electricity, regardless of time of day won't have as much impact on CO2 as plug-in advocates would like.
[Source: Automotive News - Sub. req'd]