FUTURE SELL: Cars purported to "run on water" actually run on the hydrogen extracted from water. But hydrogen used in internal combustion engines squanders its best potential, which is to power a fuel cell. Pictured: Chevrolet's hydrogen fuel-cell vehicle prototype, the Sequel. Many challenges must be overcome before fuel-cell systems will be a competitive alternative for consumers, but progress is being made.
Image: Alan Bedenko, courtesy Flickr
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Dear EarthTalk: I’ve heard that cars can be modified to run on water. How is this possible?
-- Diane McMorris, Rockport, ME
There are a number of online marketing offers of kits that will convert your car to “run on water,” but these should be viewed skeptically. These kits, which attach to the car’s engine, use electrolysis to split the water (H2O) into its component molecules—hydrogen and oxygen—and then inject the resulting hydrogen into the engine’s combustion process to power the car along with the gasoline. Doing this, they say, makes the gasoline burn cleaner and more completely, thus making the engine more efficient.
But experts say the energy equation on this type of system is not, in reality, efficient at all. For one, the electrolysis process uses energy, such as electricity in the home or the on-board car battery, to operate. By the laws of nature, then, the system uses more energy making hydrogen than the resulting hydrogen itself can supply, according to Dr. Fabio Chiara, research scientist in alternative combustion at the Center for Automotive Research at Ohio State University.
Moreover, Chiara says, the amount of greenhouse gases produced by the vehicle “would be much larger, because two combustion processes [gasoline and hydrogen] are involved.” Finally, there is a safety consideration for consumers who add these devices to their cars. “H2 is a highly flammable and explosive gas,” he says, and would require special care in installation and use.
The electrolysis process could be viable in saving energy if a renewable, non-polluting energy source such as solar or wind could be harnessed to power it, although capturing enough of that energy source on board the car would be another hurdle.
Researchers today put more focus on using hydrogen to power fuel cells, which can replace internal combustion engines to power cars and emit only water from the tailpipe. And though hydrogen is combustible and can power an internal combustion engine, to use hydrogen in that way would squander its best potential: to power a fuel cell.
Hydrogen fuel cell cars are gaining traction, but commercialization of hydrogen fuel has not yet been accomplished. “The potential benefits of fuel cells are significant,” say researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). “[H]owever, many challenges must be overcome before fuel cell systems will be a competitive alternative for consumers.”
The state of California operates a “Hydrogen Highway” program that supports development of hydrogen fuel cell technology and infrastructure. And many companies are working on ways to produce, store and dispense hydrogen. Cars powered by fuel cells are in prototype stages now, nearing production.
While we all wait to see how that shakes out, the best choice today for high mileage and low emissions is still the gasoline/electric hybrid car.
CONTACTS: Center for Automotive Research, http://car.eng.ohio-state.edu; NREL, www.nrel.gov; California Hydrogen Highway, www.hydrogenhighway.ca.gov.
SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php. EarthTalk is now a book! Details and order information at: www.emagazine.com/earthtalkbook.
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14 Comments
Add CommentThe quick and easy answer to this question is that, unless your car is steam driven, NO! The whole hydrolysis business consumes more energy electrolyzing the water to obtain the hydrogen than is realized from burning the resulting hydrogen. The second law of thermodynamics is a bitch. "You can't win, you can't break even and you can't quit the game."
Reply | Report Abuse | Link to thisOk, so, no the answer isn't strictly "NO." Yes, you CAN run a car by hydrolyzing water. It just isn't particularly efficient. The only real upside is that it is, at least the burning hydrogen part, clean. Obtaining the hydrogen in the first place might involve a less clean energy source.
Reply | Report Abuse | Link to thisSo the interesting thing about this article is that it gives a rational-sounding explanation: "Doing this, they say, makes the gasoline burn cleaner and more completely, thus making the engine more efficient," and then it fails to address that explanation in the process of debunking the idea. Yes, you get less energy out of burning the hydrogen than it takes to split the water. Of course you do. But if it also results in a more efficient burn of the gasoline, it's possible that the total energy released in both processes is greater, making this a win overall.
Reply | Report Abuse | Link to thisFurther, while it's possible that it increases greenhouse gas production because the total process is less efficient, it's unlikely to be for the reason stated. Burning hydrogen just produces water - not particularly a greenhouse gas. The reason why it might produce more greenhouse gas is because greenhouse gasses are produced by the gasoline burned to split the water. In fact, splitting water using a electricity from a green source and then burning the resultant hydrogen would result in the elimination of CO2 from the process.
All in all, an embarrassingly unscientific article for this publication. I'd still be interested to learn if there is any truth to the claim that this process would make the gasoline burn more efficiently.
I agree with Kevin's points. Also, I have to question the expert cited in the article, Dr. Chiara. For one thing, while I'm no expert, I was under the impression that hydrogen was only "explosive" if it were contained in a high pressure storage container. These "kits" release the resulting hydrogen into the air intake of the engine, it is never stored.
Reply | Report Abuse | Link to thisInterestingly the article focuses on the total "energy" required to crack the water into H and O but never addresses whether or not there's any real increase in fuel economy. Yes it takes additional electricity to crack the water, but the car is generating a current via the alternator anyway. The average consumer is more interested in paying less at the pump, not whether it's taking more joules overall to produce the result.
Reply | Report Abuse | Link to thisthis vid about an guy in pennsylvania shows an invention using saltwater that looks pretty convincing...
Reply | Report Abuse | Link to thishttp://www.youtube.com/watch?v=fMb7HgWtzGo
a guy in pennsylvania's got an invention that burns salt water that looks pretty convincing:
Reply | Report Abuse | Link to thishttp://www.youtube.com/watch?v=fMb7HgWtzGo
"Water won't aid fuel economy in today's cars"? When the cost of fuel rises high enough it will become economical to improve the efficency of the current otto cycle by using some of the energy lost heat.The Crower six stroke engine used a second powerstroke where water is injected into the cylinder, the high heat causes it to enter the superheated gas phase, forcing the pistion up. Currently the reduction in power large due to this 2nd powerstroke being weaker. I can forsee an engine with electronic valves etc which can switch between the 6 stroke cycle for economy and the four stroke cycle of power on the fly.
Reply | Report Abuse | Link to thisjust my 2 cents
Is only the hydrogen being fed into the engine? If so, why? Presumably oxygen is also being generated, so why not include that in the mixture as well?
Reply | Report Abuse | Link to thisHydrogen was the fuel of the future back in the sixties, and it will continue to be the fuel of the future until efficient production and storage of hydrogen becomes possible, and this is still a long way off, if it will ever happen...
Reply | Report Abuse | Link to thisHydrogen was the fuel of the future back in the seventies, and it will continue to be the fuel of the future unless it can be produced and stored efficiently. Neither is possible with existing technologies, so some major technological breakthroughs are required before the "hydrogen economy" will take off. In my opinion it will never happen. I agree with Emanresu that better batteries and better supercaps are much more viable.
Reply | Report Abuse | Link to thisHhhhmmm, well I guess I better go back to the Hydroxy group and tell all those people they are mistaken, that they are not really getting 20-60% fuel savings using these Hydroxy Boosters. They sure are going to be surprised. Guess their computers and calculations are just off, lol. Recon' anybody at that University gets any money from BIG OIL, nah surely not.
Reply | Report Abuse | Link to thisCharles Michael Couch
So, do ALL you guys work for big oil? Is that why you are spreading completely erroneous information on a Scientific site? I'm a member of groups of 12,000; 5,000; 8,000 people, most of whom are currently enjoying gas savings using Bob Boyce style or "Dry Cell" Hydroxy units. If Detroit hadn't engineered the ECUs on these cars to work against Hydroxy use they wouldn't be so hard to get working for huge savings on gas. But we manage to work around their nefarious designs.
Reply | Report Abuse | Link to thisSome people are running generators on 100% Hydroxy gas while making the gas and producing energy to boot. So much for your THEORY of how it doesn't work. I suggest that people who want to know the truth about these things go to Youtube and watch the videos of people doing it, instead of listening to pompous academics who are probably funded by big oil.
Charles Michael Couch
Fons is right. Hydrogen is NOT a fuel it has to be produced. And nature being what it is you get 'X' BTHUs of hydrogen out of 'X' BTHUs of fuel. A fuel cell-electric motor might be very efficient but this is more than offset by the huge inefficiency of producing the hydrogen.
Reply | Report Abuse | Link to this