United Nuclear is currently in final testing, and will shortly be producing Hydrogen conversion systems / Hydrogen generators for most fuel injected, Gasoline powered vehicles.

  Powering a vehicle by Hydrogen is by no means a new idea, and in fact, almost all automobile manufacturers are currently developing a new generation of vehicles that run on Hydrogen as opposed to Gasoline. This new generation of vehicles are essentially electric cars that use a Fuel Cell instead of a battery to run the electric motor. Using a chemical process, Fuel Cells in these new vehicles convert the stored Hydrogen on board, and the Oxygen in the air, directly into electricity to power their electric motors. These new vehicles are very efficient, and in fact are more efficient than any internal combustion engine. The problem is that these new vehicles are years away from production, are very expensive, and converting to using Hydrogen fuel in this manner requires you to buy a new ( and expensive ) vehicle. All Hydrogen/Fuel Cell systems currently under development by large manufacturers have you purchase Hydrogen as you would Gasoline.
Our system comes with its own "in-home" Hydrogen generator which allows you to manufacture fuel yourself at near zero cost. 
  Our Hydrogen conversion is an intermediate approach that simply converts your existing vehicle to burn Hydrogen or Gasoline. The Gasoline fuel system remains intact and is not modified. This allows you to switch between running on Gasoline or Hydrogen at any time. The engine itself is only slightly modified, the conversion makes substantial changes to the computer & electrical system, ignition and cooling systems. Since they never have to be removed, Hydrogen fuel storage (Hydride tanks) can be installed in virtually any available space within the vehicle.. 
  The system consists of two parts, the Hydrogen fuel system in your vehicle, and a Hydrogen generating system that remains in your garage. The Hydrogen generator is either powered by solar panels on the roof of your house, a wind turbine set-up ( both of which makes your Hydrogen fuel at virtually no cost ) or with standard 110 volt AC power for rapid refueling. 

United Nuclear's 1994 Corvette converted to run on Hydrogen.
Driving range is over 700 miles per fill and fuel cost is zero.

What's Real?

  A lot has been written about converting vehicles to run hydrogen. Unfortunately, a lot of what you'll find on the internet is simply untrue.
  ANY claim of fueling a car with water, and having the water converted to Hydrogen quickly enough to power a passenger vehicle is pure B.S. The bottom line is simple physics. It takes electrical energy to break the Hydrogen-Oxygen bond in water and release the free gases... and that takes time. The more energy applied to the water, the faster the gasses will evolve... up to a point.
It is not possible to create sufficient amounts Hydrogen gas from water (on board the vehicle) fast enough to idle the smallest passenger vehicle. If your towing a nuclear reactor behind the car, along with a motor home-sized Hydrogen generator, you might have sufficient power and volume to accomplish the task, but that kind of defeats the purpose behind the conversion.
  You can produce your own Hydrogen from electricity using either common "household current" or directly from solar cells so your energy cost is zero. It does however take a substantial amount of time to produce sufficient Hydrogen to fill even a small tank.
  As an example, it takes over 2 days of our generator running at full power, 24 hours a day, to fill our smallest "short range" tank.

Storage

   Since you can't make Hydrogen quickly enough to power a car in real time, you must produce it separately, and store it as you store your Gasoline fuel supply in your vehicle now.
There are but 3 ways to do this:

1. Store the Hydrogen as a compressed gas.
2. Store the Hydrogen as a liquid.
3. Store the Hydrogen chemically bonded to a chemical.

We'll cover each option in order.

1. If you choose to store the Hydrogen as a compressed gas, you'll need HUGE tanks, and many of them, since Hydrogen isn't very dense, so a tank really can't hold all that much. In addition, you'll be driving a giant bomb. In a collision, expect to die in a huge fireball/explosion.

2. Choosing liquid does solve the density problem since liquids are far more dense than gasses, so you can reduce the amount of tanks and their sizes required to power the car. The new problem that pops up is the fact the liquid Hydrogen in cryogenic... in short REALLY cold. It requires vacuum-thermos ( dewar ) tanks and vents to exhaust the boiling Hydrogen gas. You'll also have to find a source for liquid Hydrogen which is far more expensive than Gasoline. You've also now increased you danger factor when it comes to a collision. Not only will you have more Hydrogen gas spewing around that's going to explode and burn, but you'll also have a liquid spraying about that's over 400 degrees below zero. Once you add in the added complexity of the system due to the cryogenic liquid, your vehicle will wind up being a giant, low efficiency, rolling bomb that costs more than your house, and costs far more to run than it did on Gasoline.

3. The 3rd option is simply the only way to go. There are materials call Hydrides that absorb Hydrogen like a sponge absorbs water. Typically, the tanks are filled with granulated Hydrides, and Hydrogen is pressurized into the material. Hydrides have many advantages over liquid & gas. One is that the density of the Hydrogen stored in the Hydride can be GREATER than that of liquid Hydrogen. This translates directly into smaller and fewer storage tanks.
Once the Hydride is "charged" with Hydrogen, the Hydrogen becomes chemically bonded to the chemical. Even opening the tank, or cutting it in half will not release the Hydrogen gas. In addition, you could even fire incendiary bullets through the tank and the Hydride would only smolder like a cigarette. It is in fact, a safer storage system than your Gasoline tank is.
Then how do you get the Hydrogen back out? To release the Hydrogen gas from the Hydride, it simply needs to be heated. This is either done electrically, using the waste exhaust heat, or using the waste radiator coolant heat.

  Our vehicle starts on Gasoline and runs for about 5 minutes to heat everything up ( including the Hydride ). The time it takes to heat up the Hydride is about as long as it takes the heater in your car to warm up and blow out hot air. As soon at the Hydride is sufficiently warm, Hydrogen is released from the tanks and the on-board computer detects the presence of Hydrogen pressure.
The fuel system then seamlessly switches over to Hydrogen and remains in that mode until no more Hydrogen is released from the tanks. Leaving the Gasoline fuel system intact also enables you to run on Gasoline should you ever run out of Hydrogen.

   The only exhaust products from using Hydrogen as a fuel are steam ( water vapor ) and a tiny amount of Nitrogen Oxides. It's about as clean burning as you can get.

"Short Range" Hydride tank placement in Corvette.
We just added an additional tank to the configuration shown here. Range with these smaller tanks is now just under 300 miles and leaves some luggage/trunk room.
( not that the Corvette really had any room to begin with )

Close-up shot of the updated Hydride tank installation.

There are a few small problems that remain before the conversion units can be offered for sale.

   Currently, the biggest stumbling block of the Hydrogen fuel system at this point is the cost of the metal Hydride itself. At current prices, the required amount of metal Hydride costs between $7,000 to $18,000 per vehicle. We use a base blend of Iron/Titanium/Manganese/Lithium Hydride with a few other trace metals that increase efficiency. We are actively working with the chemical manufacturer to reduce the price of this material. We're now told that we can expect a 70% reduction in Hydride costs once production is geared up for expected demand. This would reduce the cost of the Hydride storage tanks to $3,000 to $5,000 per vehicle.
Our lower cost Hydride tanks should be available by 1st quarter 2004.

   Our second headache deals with tank refilling. If air (or Oxygen) ever contacts the Hydride material, it is permanently destroyed. Our current prototype refilling system purges the fuel lines & tanks with Argon gas prior to filling to ensure there is no residual air left in the fuel refill line. This is a clumsy & time consuming process that we should have eliminated by the time sales are ready.