In 2007, the U.S. Department of Transportation issued a final report outlining the use of hydrogen fuel in commercial vehicles. The report stated the use of hydrogen injection systems, essentially an HHO system, could be used to increase mileage and reduce emissions in commercial diesel vehicles.
The report was embraced by fringe energy theorists as justification of years of hard work. It was also embraced by the clean and renewable energy crowd as a battlefield win in the war to used hydrogen -- one of the most plentiful elements in the universe -- as a viable future fuel source.
So, Brown and Verne were correct -- to a point.
Using electrolysis to create Brown's Gas does work. Most systems use a stack of steel plates that act as positive and negative poles for electricity from the car's alternator. The current, with the help of a salt (potassium hydroxide), rips apart the molecular bonds that hold a water molecule together. The gas is pulled into the intake manifold by the engine vacuum. The gas is either used to increase the quality of the fuel burn, increase mileage and reduce emissions, or replace a portion of the fuel.
Physicists, and physical laws, point out it takes more energy to create the gas. In other words, the system's output is less than its input. Critics also urge interested parties to look at how much gas it takes to power a car, as opposed to how much oxyhydrogen is necessary to replace an equivalent amount of fuel. More importantly, a car's alternator can't produce the current to generate that much HHO.
Despite the controversy, HHO systems are fascinating -- they represent a potential, and they're a great source of inspiration for tinkerers, dreamers and people who like to build quirky and off-beat technology.
Do they work? Probably not, but then again -- maybe you'll see a Sasquatch driving a water-powered Pinto someday.