The third generation in alternative fuel power!
California Tribrid is a co-operative designed to combine research in renewable energy powered vehicles between developers in the forefront of this technology in California and Western Australia. 
Hybrids carry two sources of on-board energy. The primary energy source is most often some sort of liquid fuel (e.g., gasoline) that will in time be converted into mechanical power via an engine of some sort. This mechanical power will then be harnessed, via a “drive train” (transmission, drive shaft and/or differential) that ultimately serves to turn the wheels and thus move the vehicle - even if somewhat inefficiently.
The second source of energy on board a typical hybrid is electricity. This electricity is manufactured on-board, most often via the turning of a mechanical generator. The resultant electrical energy is then stored in batteries where it resides until supplied to an electric motor. The electric motor is used periodically to assist the gasoline engine under certain heavy-load conditions. Generally speaking the electric motor kicks in when the vehicle is starting up from a dead stop or when it is climbing up a hill.
Tribrids work in much the same way as hybrids, except that some form of the stored or generated energy either has been, or is being taken, from the ambient environment. A free-energy capturing device such as a solar panel, windmill or sail provides the tribrid vehicle with a source of power that, if left un-captured, is otherwise simply lost to the atmosphere.