This is an attempt to lay out a number of variant power systems for personal and family transport aka the motor in the family car, what are its kindred in other dimensions?
Flywheel
Light Cube is the slang term for a small cube of fiber optic cables which if stretched out would circle the world 2.7 times at the Equator, mind you. The laser energy is pumped into the cube, and is unable to escape so it circles nearly endlessly bouncing off almost perfect mirrors as it goes.
This laser in most universes heats steam to run a turbine. However, in some it starts a micro-fusion reaction in the Micro-Fusion Reactor. The MFR produces ten kilowatts of power every second, or less often if not needed. This is a spike producing system, and it has batteries to even out the spike.
Still racers try to 'hit the spike' that infintesimal moment of extra power when they need it.
Also, the primary difference between a light cube and a light grenade is that the grenade has a protective coat and is safer. Cubes have the strength of glass, and are protected inside the car by severe defenses. However, if you take a charged one out, and drop it on concrete, then everything within two feet will be Annihilated. The destructive effect tails down to nothing at ten feet.
However, if there is sufficient mass in the area, you also face a secondary risk out to forty feet (and tailing from Lethal to Annoying) of the electrons and protons of the ...say car front half....that got vaped are all going to rushing outward too with lots of energy. Its like taking a VERY high intensity X-ray...to a degree.
This extreme speed of action, and thoroughness of destruction has made 'dropping the cube' a slang term for suicide, and its thought that such is the third leading method of suicide.
The movie Shining Through dramatized one such case. The unhappy youth decided to drop, and then after he did, he rethought and dived for safety as it fell to the ground.
He got far enough that he only lost his legs and got third degree burns over the rest of his body. However, he lived, and now works for lifesaving organizations as a spokesperson.
Power Cell--This is the SF par excellence power system for local use. In its genericness its similar to the Credit. No explanation will be given. It works.
Tightly Focused Magnetics--This is a method of pumping energy into a magnetic field, and then tightening the field down.
Embedded Powerline in Roadway--There is a cable running down the center of the road. Cars on it receive radio power, or extend a 'contact dipper' to the cable through which electric power flows.
Solar Sheets--Thin film solar panels or sheets are placed all over the car. It does not produce high speeds, and its more practical in Arizona than Chicago.
Hydrogen
Fuel-Cell
Battery
Advanced Battery
Superconducting Battery
Quantum Entanglement
Orbital Laser Power Boost
Nanite Battery
External Combustion Engine
Human Powered--Usually single or duo vehicles, these very advanced bikes have a teardrop shape made of a near frictionless material and can do seventy miles per hour on level ground. They are extremely light being made of foam composites.
I'll get back to the rest later.
Eric
Two come to the top of my head quickly.
Your mention of hydrogen reminds me of a system in development that enables cars to run on water. If I understand the system, the tank contains pellets of an aluminum/gallium alloy, and is filled with fresh clean water. The pellets act something like a catalyst, such that as current is added electrolysis occurs, producing hydrogen collected and burned in the motor. The pellets need to be restored periodically by subjecting them to a reversed electrical charge, but they can go through quite a few tanks of water and produce more power than they consume (I'm not sure how--it's a chemistry thing). It also means that you can have a hydrogen car that does not have a hydrogen tank, as the fuel can be produced on demand.
The other is a technique I read years ago, which General Electric was exploring for electric cars. Instead of using batteries, they were experimenting with capacitors.
A capacitor physically is essentially two conductive plates separated by a thick insulator such that electrons cannot pass through but the attractive/repulsive force can. Thus if you push a lot of electrons onto one plate you get a highly negatively charged plate, and they in turn push a lot of electrons off the other plate to create a positively charged opposite plate. This is already used in strobes and strobe flashes, in which the battery, which can deliver a high voltage at a low current, charges the capacitor to its own voltage level, and then the closing of the switch releases that power abruptly in a high current output, producing the flash. The trick for the car is to charge up the capacitor bank and then regulate the release of power from it slowly. The primary advantage is that the capacitor can be charged very quickly from a system with a high enough voltage able to meet the current demands, while a battery would take a considerably longer time.
I use that idea in the design of the power cells in most of my kinetic blasters. Since these fire pulses very like strobes, it makes sense for the "power cell" to be capacitive. It can be recharged slowly to very high voltage and dicharged abruptly in a burst at high current.
--M. J. Young