A water-fuelled car is an automobile that supposedly derives its energy directly from water. Water-fuelled cars have been the subject of numerous international patents, newspaper and popular science magazine articles, local television news coverage, and the internet. All or some of the claims for these devices have been found to be incorrect and some were found to be tied to investment frauds. These vehicles may be claimed to produce fuel from water on board with no other energy input, or may be a hybrid of sorts claiming to get energy from both water and a conventional source (such as gasoline).
This article focuses on vehicles that claim to extract chemical potential energy directly from water. Water is fully oxidized hydrogen. Hydrogen itself is a high-energy, flammable substance, but its useful energy is released when water is formed--water will not burn. The process of electrolysis, discussed below, would split water into hydrogen and oxygen, but it takes as much energy to take apart a water molecule as was released when the hydrogen was oxidized to form water. In fact, some energy would be lost in converting water to hydrogen and then burning the hydrogen because some heat would always be produced in the conversions. Releasing chemical energy from water would therefore violate the first and/or second laws of thermodynamics.
A water-fuelled car is not any of the following:
The energy content of fuels is often represented by the heat of combustion, measured by burning a fuel in oxygen. A value in joules, for example, cannot even be given to water as it does not burn in oxygen and produce any heat. Water is a low-energy, stable compound that is produced from the oxidation of high-energy substances such as molecular hydrogen or hydrocarbons. Spontaneous chemical reactions are the types of reactions that can be utilized to release energy for useful work. In spontaneous chemical reactions, the reactants will be higher in energy than the products. When fossil fuels are burned, the hydrogen is oxidized to water, releasing its stored energy, and the carbon is oxidized to carbon dioxide, another low-energy compound.
Nonspontaneous chemical reactions do not release energy, and energy must be provided for the reactions to take place. These types of reactions store energy. For example, the electrolysis of water, a process that consumes energy, produces molecular hydrogen, which represents a store of chemical energy.
Proponents of water-fuelled cars point out the abundance and low cost of water; however, water is such an abundant chemical compound in part because it has very stable bonds that resist most reactions. Water will not even burn in oxygen, although it will burn with fluorine as an electron acceptor. Because fluorine is so reactive, however, most of it has been converted to fluoride, and producing fluorine would also require energy. For water to participate in a reaction that releases 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. Under conditions common on Earth, chemical energy cannot be extracted from water alone. (It is theoretically possible to extract nuclear energy from water by fusion, but fusion power plants of any scale remain impractical, and no allegedly water-fuelled cars are claimed to be powered by fusion.)
Many alleged water-fuelled cars obtain hydrogen or a mixture of hydrogen and oxygen (sometimes called "oxyhydrogen", "HHO", or "Brown's Gas") by the electrolysis of water, a process that must be powered with electricity. The hydrogen or oxyhydrogen is then burned, supposedly powering the car and also providing the energy to electrolyse more water. The overall process can be represented by the following chemical equations:
Since the combustion step is the exact reverse of the electrolysis step, the energy released in combustion exactly equals the energy consumed in the electrolysis step, and—even assuming 100% efficiency—there would be no energy left over to power the car. In other words, such systems start and end in the same thermodynamic state, and are therefore perpetual motion machines, violating the first law of thermodynamics. Furthermore, under actual conditions in which hydrogen is burned, efficiency is limited by the second law of thermodynamics and is likely to be around 20%. More energy is therefore required to drive the electrolysis cell than can be extracted from burning the resulting hydrogen-oxygen mixture.
Stanley Meyer claimed that he ran a dune buggy on water instead of petrol. 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 vapour 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 aneurysm in 1998, and conspiracy theories persist claiming that he was poisoned.
Charles H. Garrett 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. 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 firm Hydrogen Technology Applications has also patented an electrolyser design and has trademarked the term "Aquygen" to refer to the hydrogen oxygen gas mixture produced by the device. Originally developed as an alternative to oxyacetylene welding, the company also claims to be able to run a vehicle exclusively on "Aquygen" and invoke an unproven state of matter called "magnegases" and a discredited theory about magnecules to explain their results. Company founder Dennis Klein claims to be in negotiations with a major US auto manufacturer and that the US government wants to produce Hummers that use his technology.
In June 2008, Japanese company Genepax unveiled a car which it claims runs on only 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 a hydride-fuelled "hydrogen on demand" vehicle, rather than water-fuelled as claimed. On the company's website 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."
Also in 2008, Sri Lankan news sources reported that Thushara Priyamal Edirisinghe claimed to drive a water-fuelled car about 300 kilometers on three liters of water. Like other alleged water-fuelled cars described above, energy for the car is supposedly produced by splitting water into hydrogen and oxygen using electrolysis, and then burning the gases in the engine. Thushara showed the technology to Prime Minister Ratnasiri Wickramanayaka, who "extended the Government’s full support to his efforts to introduce the water-powered car to the Sri Lankan market."
Thushara was arrested a few months later on suspicion of investment fraud.
Daniel Dingel, a Filipino inventor, has been claiming since 1969 to have developed technology allowing water to be used as fuel. In 2000, Dingel entered into a business partnership with Formosa Plastics Group to further develop the technology. In 2008, Formosa Plastics successfully sued Dingel for fraud, with the 82-year-old Dingel being sentenced to 20 years imprisonment.
In addition to claims of cars that run exclusively on water, there have also been claims that burning hydrogen or oxyhydrogen in addition to petrol or diesel fuel increases mileage. Around 1970, Yull Brown developed technology which allegedly allows cars to burn fuel more efficiently while improving emissions. In Brown's design, a hydrogen oxygen mixture (so-called "Brown's Gas") is generated by the electrolysis of water, and then fed into the engine through the air intake system. Whether the system actually improves emissions or fuel efficiency is debated. Similarly, Hydrogen Technology Applications claims to be able increase fuel efficiency by bubbling "Aquyen" into the fuel tank.
A common fallacy found in connection with this type of modification is the mistaken assumption that cars generate excess electricity via their alternators that normally goes to waste and therefore is available for electrolysis. The amount of force required to turn an alternator or generator depends strictly on the electrical resistance of the circuits it is supplying, and residual heat lost due to friction. If an electrolysis unit is added to a car, the amperage it draws from the car's electrical system will make the alternator harder to turn, which will put additional drag on the engine. As a result more fuel will be required to maintain the same rotational speed (RPM.) 
A number of websites exist promoting the use of oxyhydrogen (often called "HHO"), selling plans for do-it-yourself electrolysers or entire kits with the promise of large improvements in fuel efficiency. According to a spokesman for the American Automobile Association, "All of these devices look like they could probably work for you, but let me tell you they don't."
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 hydrogen on demand vehicle uses a chemical reaction to produce hydrogen from water. The hydrogen is then burned in an internal combustion engine or used in a fuel cell to generate electricity which powers the vehicle. While these may seem at first sight to be 'water-fuelled cars', they actually take their energy from the chemical that reacts with water, and vehicles of this type are not precluded by the laws of nature. Aluminium, magnesium, and sodium borohydride are substances that react with water to generate hydrogen, and all have been used in hydrogen on demand prototypes. Eventually, the chemical runs out and has to be replenished. In all cases the energy required to produce such compounds exceeds the energy obtained from their reaction with water.
One example of a hydrogen on demand device, created by scientists from the University of Minnesota and the Weizmann Institute of Science, uses boron to generate hydrogen from water. An article in New Scientist in July 2006 described the power source under the headline "A fuel tank full of water," and they quote Abu-Hamed as saying:
|“||The aim is to produce the hydrogen on-board at a rate matching the demand of the car engine. We want to use the boron to save transporting and storing the hydrogen.||”|
A vehicle powered by the device would take on water and boron instead of petrol, and generate boron trioxide. The chemical reactions describing the energy generation are:
The balanced chemical equation representing the overall process (hydrogen generation and combustion) is:
As shown above, boron trioxide is the only net byproduct, and it could be removed from the car and turned back into boron and reused. Electricity input is required to complete this process, which Al-Hamed suggests could come from solar panels.
The Water Engine, a David Mamet play, made into a television film in 1994, tells the story of Charles Lang inventing an engine that runs using water for fuel. The plot centers on the many obstacles the inventor must overcome to patent his device.
A formula for a water-fueled engine and the car developed with it is central to the plot of the children's film Frank Enstein.