A water-fuelled car is a motor car that uses water as its fuel or produces fuel from water onboard, with no other energy input. Water-fuelled cars have been mentioned in history books, newspaper and popular science magazines, and urban legends since the 1800s; at least some of the claims were found to be tied to investment frauds. This article is restricted to those cars or motors which purport to extract their energy directly from water, a process which would violate the first and/or second laws of thermodynamics.
What water-fuelled cars are not
A water-fueled car is not any of the following:
- The steam engine: A steam engine uses water to transmit energy from the fire or other heat source to the pistons or turbine that do the work of turning the engine.
- The Crower six stroke, which adds two extra strokes to the customary internal combustion engine four stroke Otto cycle, to produce and exhaust steam from water, while venting heat from the engine.
- water injection which is a method for cooling the combustion chambers of engines by adding water to the incoming fuel-air mixture, allowing for greater compression ratios and reduced engine knocking (detonation).
- The hydrogen car, although it often incorporates some of the same elements. To fuel a hydrogen car from water, energy from a power plant is used to generate hydrogen by electrolysis. The resulting hydrogen is then either burned in the car's engine or merged with oxygen to create water via a fuel cell. The car ultimately receives its energy from the power plant, with the hydrogen acting as an energy carrier.
- Hydrogen fuel enhancement systems.
Chemical energy content of water
The burning of conventional fuels such as petrol (gasoline), wood, and coal converts the fuel into substances with less energy (see enthalpy of combustion). Energy is released. In the case of most fossil fuels, combustion can be represented with the following chemical equation:
Water is a waste product.
Spontaneous chemical processes do not create energy, they release it by converting unstable bonds into more stable bonds and/or by increasing entropy. Water is such an abundant chemical compound in part because it has very stable bonds that resist most reactions. In order for water to participate in a reaction that produces energy, high energy compounds must be added. For example, it is possible to generate the combustible fuel acetylene by adding calcium carbide to water. However, the calcium carbide, a high energy material, is the 'fuel,' not water.
It is theoretically possible to extract energy from water by nuclear fusion, but fusion power plants of any scale remain impractical, much less on an automotive platform.
Electrolysis
- See also: Electrolysis
Claimed water fuelled engines often obtain hydrogen by electrolysis of water. The electrolysis cell must be powered electrically. The hydrogen and oxygen obtained by this electrolysis can then be burned but more energy is required to drive the electrolysis cell than can be extracted from the resulting hydrogen-oxygen mixture. Otherwise, such a system would be equivalent to a perpetual motion machine.
When hydrogen is burned, the heat it creates can be converted into work by a conventional Otto cycle car engine, but the efficiency of such engines is limited by the second law of thermodynamics and is likely to be around 20%. Because a conventional electric motor does not use heat, it can theoretically have an efficiency close to 100%. 94% efficient motors of sufficient power to drive a car are commonplace.
Technology
Genepax Water Energy System
In June 2008, Japanese company Genepax unveiled a car claimed to run on water and air, and many news outlets dubbed the vehicle a "water-fuel car". The company says it "cannot [reveal] the core part of this invention,” yet, but it has disclosed that the system uses an onboard energy generator (a "membrane electrode assembly") to extract the hydrogen using a "mechanism which is similar to the method in which hydrogen is produced by a reaction of metal hydride and water". The hydrogen is then used to generate energy to run the car. This has led to speculation that the metal hydride is consumed in the process and is the ultimate source of the car's energy, making the car hydride-, rather than water-fuelled. The company has said that it has filed for a patent. On June 27th 2008 they released information in English on their website, where the energy source is explained only with the words "Chemical reaction". The science and technology magazine Popular Mechanics has described Genepax's claims as "Rubbish."
Stanley Meyer's water fuel cell
Meyer claimed he ran his 1.6 liter Volkswagen dune buggy on water instead of gasoline. He replaced the spark plugs with "injectors" to spray a fine mist of water into the engine cylinders, which he claimed were subjected to an electrical resonance. The fuel cell would split the water mist into hydrogen and oxygen gas, which would then be combusted back into water vapor in a conventional internal combustion engine to produce net energy. Meyer's claims were never independently verified, and in 1996 he was found guilty of fraud in an Ohio court. He died of an aneurism in 1998, although conspiracy theories persist that he was poisoned.
Garrett electrolytic carburetor
Charles H. Garrett from Dallas, Texas allegedly demonstrated a water-fuelled car "for several minutes", which was reported on September 8, 1935 in The Dallas Morning News. The car generated hydrogen by electrolysis as can be seen by examining Garrett's patent, issued that same year.U.S. Patent 2,006,676 This patent includes drawings which show a carburetor similar to an ordinary float-type carburetor but with electrolysis plates in the lower portion, and where the float is used to maintain the level of the water. Garrett's patent fails to identify a new source of energy.
The gasoline pill and related additives
Related to the water-fuelled car hoax are claims that additives, often a pill, convert the water into usable fuel, similar to a carbide lamp, in which a high-energy additive produces the combustible fuel. This gasoline pill has been allegedly demonstrated on a full-sized vehicle, as reported in 1980 in Mother Earth News. Once again, water itself cannot contribute any energy to the process, the additive or the pill is the fuel.
A popular science article in New Scientist in July 2006 described a new type of engine under the headline "A fuel tank full of water". By reacting water with the element boron, their system produces hydrogen that can be burnt in an internal combustion engine or fed to a fuel cell to generate electricity. The only by-product is boron oxide, which can be removed from the car, turned back into boron, and used again. A number of chemical compounds combine with water to release hydrogen, but in all cases the energy required to produce such compounds exceeds the energy obtained upon their combustion.
Fusion may be closer than you think:
Fusion Report 13 June 008