Thursday, August 19, 2010

Why use hydrogen instead of batteries for cars?

I have been puzzling over this for a while.





There's a lot of research going into hydrogen storage methods, because storing enough hydrogen to compete with a good ol' gas tank is a major problem.





Then there is the problem of where you're going to get the hydrogen, how you're going to get it to a pump, etc.





Why mess around with this when we can just make all-electric cars? Wouldn't the money be better spent on battery research?





Thermodynamically, the loss of energy involved with hydrogen production, phase changes, chemical reactions in a fuel cell, fuel transportation, etc. make it impossible for hydrogen to beat a purely electric solution.





Electricity is easily distributed on existing networks and is a very efficient means of storing and using energy.





Anyone care to explain why so many people are big on hydrogen when we could be going straight for electric?

Why use hydrogen instead of batteries for cars?
Hydrogen covers 2 technologies,


1) burning in an infernal combustion engine - various fuel management problems; but existing technology.


2) producing eletric in a fuel cell - this is where most of the research is going





Batteries can be recharged in 10 minutes; http://www.altairnano.com/markets_amps.h...


after 200 miles I hope most drivers would want a 10 minute stop.


in everyday use refuel at home on off-peak renewable electric supply (resell unused capacity during day to help balance vaiablity in renewable supply) or from home micro-generator. http://www.acpropulsion.com/technology/v...





As you say hydrogen small molecules is not very energy dense, and escapes easilly, so is hard to distribute efficiently. and to carry enough for more than 100 mile range.





So why hydrogen?


1) preserves Big oil %26amp; government control (they will not want people brewing their own hydrogen in basements.)


2) delays taking action now, but looks like something being done.


3) diverts funds from battery research to big oil %26amp; major car makers
Reply:Well I agree that hydrogen technology is getting too much attention and funding relative to electric vehicle technology. We've already had an extremely successful electric car (EV1) and several other good models (ZAP Xebra, Tesla Roadster, soon ZAP-X, etc.), whereas hydrogen car technology still has several roadblocks to surmount and is a long ways off.





However, both technologies should be funded. I think electric cars should get more of our resources because it's a very low emission solution that we could be implementing immediately. Hydrogen is a potentially very low emission solution that won't be implemented for several decades yet.





The aluminum alloy technology for producing hydrogen does sound very promising because it elminates the problems of hydrogen fuel storage and transportation infrastructure. Essentially the combination of water and the aluminum alloy produces hydrogen. Further details are available here:





http://www.physorg.com/news98556080.html





This is very promising technology, but is still a long way off. They want to try it in small engines like chainsaws and lawn mowers first, then implement it on a larger scale for cars if that works. They predict that "when and if fuel cells become economically viable, our method would compete with gasoline at $3 per gallon even if aluminum costs more than a dollar per pound." but electricity currently costs less than that, so initial cost of an electric vs. hydrogen vehicle would be critical.





Basically both should be funded, but electric vehicles should be given more attention as an important solution that can be implemented immediately.
Reply:batteries are much to heavy for long drives (storage of energy would require large batteries)





and how would you refuel? it takes to long now to refuel batteries. hyrdogen would fill just like a gas tank. batteries would have to sit and charge for hours.
Reply:Because hydrogen weighs a lot less than batteries with the same energy content. Cars can be lighter and use less energy to move them. Also, it's much faster to refuel a hydrogen car than charge a battery one. That's important on long trips.





It's not an easy decision. Your concerns about hydrogen are very valid. It's going to take a lot of work to figure out which way to go. Maybe batteries for the city and hydrogen for long trips.
Reply:From what I have heard the hydrogen car is not a viable option. I am with you why not just use electric cars. That technology is already developed. I liked who killed the electric car it was an important movie. The battery technology had improved signifigantly but the company that made the batteries was shut down after it was purchased. Good question. Personally I would really like to have an electric car and not have to settle with a hybrid. Perhaps we can get them going again if there is more interest.
Reply:A hydrogen fuel cell prettymuch is a battery. It 'recharges' quicker, because you can just add more hydrogen. But, you still need to generate electricity to produce the hydrogen, just like you need it to charge the batter.





One big reason is the fuel paradigm. Energy companies are used to delivering energy to vehicles at gas stations. They're uncomfortable with the idea of vehicles drawing power from existing lines. Think about it, there are gas stations on every corner.
Reply:Researchers at Purdue are working on a aluminum-gallium catalyst that will allow separation of water so efficiently we will be able to run our cars off of "water" that is separated into hydrogen and oxygen in the fuel system. I believe it is the most promising technology we have for the future and if they are successful it will revolutionize the world.
Reply:Comes down to weight and portability. The technologies we have make both suitable as power sources. It is actually likely that both technologies will be used together. Can't capture braking energy with H2.





There are many reasons for batteries over H2, other than disposal.
Reply:Many chemicals in electric batteries are very harmful to the environment. Have you ever seen a warning on battery packages to not touch batteries that have leaked out the chemicals? They can be highly toxic. Also, the heavy metals used in batteries will eventually end up in the trash and will not be easily biodegradable. Also, electric batteries are not efficient enough to compete with gasoline. You have to charge your car for hours to get it to run for a day. That is why may car companies have created "hybrids" which use both gasoline and electricity, so that the massive amounts of energy released from gasoline can make up for the inefficiency of electric batteries. (at least, with the technology we have today, electric cars are inefficient)





The hydrogen fuel cell, on the other hand, is much more efficient. More importantly, it is incredibly clean. The reaction taking place in a hydrogen fuel cell yields only water. Hydrogen and Oxygen molecules release energy when they combine to form water (H2O), which is not damaging at all to our environment. Actually, many scientists are eager to perfect the hydrogen fuel cell for use in space travel, where water created by the fuel cell can be used to support the astronauts.





However, with the limited technology we have today, electricity as a power source is much more feasible and realistic. But once the hydrogen fuel cell is perfected and made into wide use, it will greatly benefit everyone, as well as the environment.
Reply:If hydrogen could be made more efficiently and some of the problems you mentioned were resolved, then it could be better for the environment since there are no emissions and no batteries to dispose of. I agree that electric is a much more feasible solution at this point in time, but I think we should also be looking into possible solutions, and I think hydrogen has a lot of problems but if we don't do the research then we could never solve those problems!
Reply:The answer is essentially range - If you're taking a long trip, you need to be able to refill quickly and get back on the road with acceptable range available. Battery electric vehicles are ideal commuter cars, but not really good for a family road-trip until you can get a charge worth 200+ miles in less than an hour at a rest area off the interstate!
Reply:Because batteries will still end up....in the trash. And you still have to charge them. Electricity is a major form of pollution since most is still coal based.





Well aren't you a pompus jerk! The hope for hydrogen cells is that it can be generated without coal or oil or gas thereby reducing dependency on oil and pollutants. You should refrain from asking question until you remove your head from your ***.





Furthermore hydrogen fuel cells would emit water as a byproduct as opposed to anything else potentially harmful.





The technology for battery has been around for a while however no one has been able to figure out an efficient way for battery powered vehicles to travel any amount of distance, hence the hybrids. They are hoping to remove that obstacle with hydrogen.
Reply:Like the author of this question, I've been puzzling over the buzz regarding the hydrogen economy as well. But I'm equally puzzled over the enthusiasm surrounding electric cars, at least ones that are plugged into the power grid. As the author and several of the responders fully understand, these two technologies are only as environmentally friendly as the energy source. To me the frustrating thing isn't one car technology versus the other. What frustrates me is why the attention of the media hasn't shifted to the question of eco-friendly energy sources. I think most of the important issues have been captured by the author and many of the responders. But here are a few additional thoughts...


- If the supply chain for hydrogen has the significant inefficiencies that the author points out, then it seems hopeful that market forces will weed out the less efficient alternative. People don't like throwing money down the drain. So I think there is room for optimism.


- One of the largest auto makers has stated that they're keen on hydrogen because it removes the car from the environmental equation. Which isn't the same thing as solving environmental problems. As another reader has pointed out, this just shifts the problem to the hydrogen producer, unless you address the issue of clean sources of electricity and/or hydrogen.


- Why isn't methane also receiving more attention. At the time of the first Earth Day (was that 1970?), I did a report for high school on alternative vehicle technologies. I got some literature from SDG%26amp;E regarding their fleet of natural gas powered vehicles. The technology has been in use for decades. Even by the Post Office. Why not more enthusiasm over production of methane via anaerobic digestion of trash, sewage and other biomass? As most of the people responding to this posting will understand, a car running on methane produced from bio-mass is better for global warming than an electric or hydrogen vehicle that derives its energy from a coal-fired plant.


- What really scares me is if the public buys into the hydrogen vision or all-electric vision without fully understanding that this question of "where do you get it" isn't just a detail... it's the real story. We could end up moving on a large scale to burning coal and doing carbon capture and sequestration. Is this really a sustainable solution? For every carbon atom that is captured and returned to the earth this process would capture three atoms of oxygen from the atmosphere, permanently trapping two of those oxygen atoms underground and binding the third oxygen atom into a water mollecule. Do we really want to start scrubbing oxygen from the atmosphere permanently and on a large scale? I really worry over whether the public will get lulled into thinking that they've gone eco just because "nothing but water is coming out the tailpipe", or it's powered by "clean electricity", or our coal-fired plants are now eco-friendly because we've captured the green-house gases.


- Even though powering cars with electricity off the grid doesn't in itself solve anything (unless the power sources are clean), I nevertheless do hope that the car industry moves to cars with electric motor drive-trains. (Hybrids are overly complex.) With electric motors driving the wheels, we can completely de-couple the problem of power delivery to the wheels from the problem of energy source. The car and drive-train become a fixed, known quantity. And the people with the bright ideas can focus upon the competing energy sources: internal combustion or turbines turning generators and powered by diesel, gasoline, ethanol, methane, hydrogen, bio-diesel; photo-voltaic cells; batteries charged up from the grid; hydrogen fuel cells; re-generative braking; capture of waste heat from engines and exhaust to produce additional electricity using thermo-electric technology or such, etc. Then the car companies could concentrate on what they do well... after all cars are a very mature technology and even GM produces a great electric motor that they bought from Paul McCready when they acquired Impact. Wouldn't it be great if the auto companies could just specify the space that the energy source needs to fit into, and all the entrepreneurs could build to that spec... may the best solution win. If we split the problem in two, and let the young innovators come up with the power source(s), and let the auto companies do what they do well, then I think innovation would be greatly accelerated.


- The open source car project has similar thinking regarding the value of de-coupling the power source from the electric-motor drive-train.
Reply:You're not solving anything, that electricity you are using to power those electric cars still has to be derived most likely from fossil fuels, i.e. coal burning.





The hype about hydrogen was that you could power a car using one of the most abundant resources on our planet, water. The real problem with Hydrogen cars? Think about it's usages, Hydrogen bomb, the linden-burg (that big blimp that blew up) was full of it. They can't seem to make it safe since hydrogen is highly reactive.
Reply:One very big advantage with hydrogen is that it is relatively inexpensive to retrofit an existing internal combstion gasoline powered engine to operate on hydrogen.





We do not have to buy new cars and it is much cheaper and easier to retrofit an existing gasoline powered automobile to run on hydrogen than it is to convert an existing gasoline powered automobile to run on electricity. The equipment, and parts to convert a gasoline engine to hydrogen are available now, all we have to do is increse production to convert a large number of existing cars to hydrogen.





Batteries are very heavy and add a huge weight penalty to the car which cuts down considerably on the mileage that you get for a given amount of electricity. Hydrogen powered cars are much lighter in weight.





Also mining the metals for the batteries, particularly lead, creates a great deal of pollution as does recycling the batteries.





Hydrogen can be generated electrolytically from water. There is equipment currently available that can be installed in your home to generate hydrogen electrolytically using electricity from the electric power grid. The hydrogen generated is then used to refuel the vehicle. You do not need to go to a special refueling station that sells hydrogen.





With the equipment currently available on the market it requires approximately 50 kilowatt hours of electricity to produce an amount of hydrogen that has an energy content equal to one gallon of gasoline.





If you use a renewable resource such as windpower to produce the electricity it is essentialy non pollutiing.





Incidentally I have calculated that it would require approximately 950,000 wind turbines of 1.8 megaeatt capacity each, operating 30% of the time to produce enough electricity to produce the hydrogen that it would take to replace all of the gasoline used in the United States with an amount of hydrogen equal in energy content. to the gasoline that it replaced.








If you use a fossil fuel such as coal or natural gas to produce the electricity, you are just transferring the pollution to another location.
Reply:There is the hydrogen cell which is much like the shape and size of a hockey puck that has been developed and is in use at Ford and GM research facilities. To get the amount of batteries to soley propel a vehicle requires too m,uch weight.


So the advantages of hydrogen cell is that the waste product is water, the cells are small and lightweight, and they are being used in mass transit in England. BUT conversion to a totally new technology such as this would require commitment and money. Plus there is a BIG movement here from the agricultural folks for ethanol. The most green idea however, and the one I like, is the Hydrogen cell.


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