Here's another reference about the local (well, state-level) sources of electricity, and therefore the CO2 emissions of an EV compared to ICE, hybrid, and plug-in hybrid vehicles:
Alternative Fuels Data Center: Emissions from Hybrid and Plug-In Electric Vehicles
As others have said, you can increase your use of clean power by changing your supplier or by installing solar panels on your house. There are questions of how you do the accounting, though. For instance, some solar programs assign the Renewable Energy Credits (RECs) to the utility, so having solar panels on your house might not give you a moral right to claim "green karma" for the solar panels. That's the way the Rhode Island Renewable Energy Growth (RI-REG) program works, for instance. I've got solar panels on my house under this program, so to get the RECs back, I also buy my power via the
Green Energy Consumers Alliance, which sources power from small-scale wind installations and then sequesters the RECs. This whole thing is a bit of a shell game, and it depends on how you choose to do the accounting -- by the physics of how the electrons flow, by RECs, by who owns the solar panels, etc. It can be simpler in some cases. In Rhode Island, for instance, installing solar panels via a net metering system enables the owner to keep the RECs, which makes the accounting methods align more closely. Unfortunately, laws vary from state to state, and electricity suppliers also vary from state to state. (Some big suppliers claim to supply power from renewable sources, but if you dig deeper, their claims are dubious or rely on REC accounting sleight-of-hand.)
