For those going PHEV/EREV/BEV route, good new is that the grid is getting cleaner faster than expected. With NG prices dropping and plants getting old, and wind/renewable picking up, coal usage for electricity generation is dropping. U.S. Coal Generation Drops 19 Percent In One Year, Leaving Coal With 36 Percent Share Of Electricity | ThinkProgress Let's hope it stays that way. A few weeks ago I attended a meeting where an engineer from Xcel (Denver's power company) had just showen folks a real-time power monitoring and he blew away the audience showing them at the city was running on almost 70% wind power. He commented the switch to NG matches very well with Xcels increase in wind as NG plants can ramp up fast enough to make up as the winds go slack.