Most promising green technologies number two: hybrids

Click above for a high-resolution gallery of the 2007 Toyota Prius Touring.

Sure, hybrids such as the Toyota Prius are already considered by the masses to be the pinnacle of green automotive technology, but they are still most certainly in their infancy. We've already looked at ultracapacitors, diesel, biodiesel and cellulosic biofuels as potential green technolgies, but each of those could be paired with an electric motor as part of a hybrid drivetrain. Although GM would like you to consider the upcoming Volt as an electric vehicle, the fact remains that it also carries a small internal-combustion engine onboard, making it a hybrid of sorts although many people (ourselves included) are referring to it as an extended-range electric vehicle. Because so many potential breakthroughs include hybrid technologies, we look forward to the idea carrying on as one of the most promising ways for automobiles to go green.

Now, what's Number 1?