Hybrids aren't just for eco-conscious soccer moms.
General Electric on Tuesday said that it has tested a hybrid version of a haul truck, the kind of giant dump truck that's used at a mine or to haul away mountains of dirt.
The system works just like a Toyota Prius, more or less. The engine feeds electricity to a battery that runs the drivetrain. During braking, the spinning wheels act as a generator for the battery.