Most promising green technologies number eight: hydraulics

Many modern vehicles already use hydraulic power for certain functions, namely power steering and brakes. Companies such as UPS, though, see potential in using hydraulic systems as part of a hybrid drivetrain. While nobody is expecting a hybrid hydraulic system to be able to store enough energy to achieve miles-upon-miles of driving distance, the frequent stopping and restarting of some vehicles - delivery trucks, to name just one obvious example - make them excellent candidates for possible hydraulic technology.

Pump on over to Number 7.