But Tesla is also working in a big battery factory, and I read this plant is very green.
But how is the batteries less green than cars producing contamination. (The batteries could be worst, that's is something I haven't even considered)¿?
My read is that their main goal is selling batteries and everything from opening their "patents" (i.e. their custom connectors/battery pack) to the home wall-pack is designed to do that.
[1] http://www.environment.ucla.edu/media/files/BatteryElectricV... (page 7 with relevant graph) Also http://www.enveurope.com/content/pdf/2190-4715-24-14.pdf (page 10/11)
BEVs have a very large upfront footprint due to the battery that needs to be paid off overtime by driving from a renewable source. However in US only 14% of energy comes from renewable sources, so it'll be a very long pay off.
Hybrids are the best way to go until we make significant strides in batteries (20-30 years off?). You rely on your charged battery for most of your trips, and the highly optimized gas engine kicks in when you need the extra range/juice.
Larger battery means a much larger up-front carbon footprint. Unfortunately on an on-going basis due to profile of electricity production in US you are burning a ton of coal [1] to generate that electricity. Coal is far, far worse than gas in the carbon impact as well as extraction footprint.
Because of the much larger initial hole you've dug (due to a very, very large battery) you're not going to crawl your way out of this deficit for a long time.
The logical solution is to minimize the battery to a degree that it would cover most weekday commutes (which isn't 300 some-odd miles). You would have a much smaller, optimized, gas based generator to recharge that battery for the odd time the person needs the longer range.
It gives you the best of both worlds. You would get far greater savings. This is the reason why other manufacturers are making hybrids or if they do make pure EV it has a much smaller battery than Tesla.
[1] http://www.mapawatt.com/2010/11/29/where-does-us-electricity...
"Our base case results suggest that a BEV uses the least amount of energy of all the vehicle types analyzed in this study, followed by a hybrid and a CV. The results of the CV lifecycle analysis show that by far the greatest source of energy intensity is the use phase, at 95% of the lifecycle energy. This is due to the amounts of energy required to extract and process the gasoline and the energy intensity of the gasoline itself."