As long as the car is running, you can keep the water from freezing right along with the passengers. I offer the following in fun in hopes of triggering a real idea: Alternative #1--Once you turn the car off, automatically dump the water. Of course you end up with icy parking spaces, but better than in the fast lane....Altenative #2-- A tank with a trapdoor bottom that releases when the water expands as it turns to ice. Same problem as before, but with nice little piles of slush.Alternative #3-- Adapt #2 to make icecube trays. What you do with the ice cubes is your business. Alternative #4-- Icecube launcher-- flings icecubes to side of road. Problems obvious if used in city. Altenative #5-- Make round pellets of ice, launch skyward and pretend its hail.... Alternative #6-- Make dump troughs at stoplights to collect ice cubes.... Sell ice cubes to bars to put in drinks.... Use proceeds to hire more traffic cops to bust drunk drivers... ( BTW: I would love to know how much water a hydrogen fuel cell car produces anyway. It may not be that big a problem.) Anyway, I hope you're not offended by some light-hearted brainstorming. Gary

I've thought about this, too, but in a different context. I live in the desert, and I wonder what's going to happen to the ecology here when there are 100,000 cars driving around spewing out h2o. Will we get perpetual fog like San Francisco or will it just kill the native plants through overwatering?Let's face it...we are WAY overpopulated and until the population is cut by about 75% any "fix" will still overwhelm the environment, just in a new way.

I don't think it will be a problem at all. All of the millions of cars already in use produce some water vapor as part of the combustion process. That's the part you can see on cold winter days. If it hasn't been a problem up to this point I don't think it will be one if everyone suddenly began driving hydrogen fuel cars.

Yeah, I'm pretty sure H2O is going to be produced as a vapor. On psiclist's point, it sounds like you're "WAY" overestimating the amount of H2O we're talking about.

Gary, I do like your humor. Its kind of like stopping at the rest area on the interstate to let your car take a leak! I did see a television show about hydrogen cars and it shows a guy holding a glass up to the tail pipe while the car is running and there is a fast drip of water coming out. But the more I thought about it, that water could also freeze inside the exhaust pipe, muffler while it sets in your driveway day after day "could" stop it up. I don't know for sure, but I thought I bring this to someones attention. ... launching ice pellets ... hahaha

Water is a byproduct of hydrogen combustion. When hydrogen burns, it leaves only water vapor (also possibly some trace compounds from the inevitible combustion of lubricating oil, plus a tiny amount of oxides of nitrogen). Burning hydrocarbons produces water vapor and carbon dioxide (and tiny amounts of some other nasty stuff, like what I just mentioned).

Frozen exhaust from burning hydrocarbons hasn't been a serious problem in the last century, frozen water from hydrogen fuel won't be a serious problem in the next century.

We'll have other, more entertaining problems.

You should be more worried that the oil companies are planning to produce the hydrogen from natural gas which if burned in an internal combustion engine will introduce a lot of new water vapour into the environment. Whats going to happen to the weather when this thermals into the atmosphere and becomes clouds? its got to come down as rain somewhere in the world. I think water vapour is also a greenhouse gas so if they produce the hydrogen from this source it is not going to be a solution to the global warming problem.

michael, I dont think that this would be a problem unless the car was at a stopped position for more than a day, then you would have a puddle under the car. The way I see it is that if you are moving forward at fifty five miles per hour, you would leave a drop of water every thirty feet, as you slow down the water drops would be closer together. On another thought about water and the earth, there is evidence that comets entering the atmosphere leave about 6000 gallons of new water on the earth every day!

Consider recycling the water. If it is relatively pure, then when a flexible bladder fills to a point, you off-load the water the next time you fill up with hydrogen. This way we introduce less minerals to be processed out of the water we use for making hydrogen and we help to limit any contamination from the engine oils from getting into the environment.

i think that the water eft over can be re used and purified to maby be bottled and sent to afica of the poor kids

Since we may be heading into long term drought in many parts, we may want to save that water. I would think it would be fairly pure, like branch water, so mix it with bourbon and have some salted cashews.

now its time to rethink the design on the automobile now the concept car are needed new materials

people need to cut deal with nation to mass produce new version and it needs to start .cheaper conveyances are a must build it and they will buy it

I believe the hydrogen car is a ruse by the oil companies to prevent people from going to electric cars. If you fill your tank with hydrogen on Monday, by Sunday, it will all leak out. The molecules are so small that they permiate the material of the tank. Sounds pretty stupid to me. And you still need energy to generate the hydrogen, so it's not really clear What is powering your car.

If hydrogen was readily available from vast underground hydrogen deposits, or huge lakes (nay, oceans) of liquid hydrogen at the poles, we could think of hydrogen as an energy source; but since there are no pools of liquid hydrogen, nor vast underground deposits, we must recognize that, at best, hydrogen is an energy STORAGE system, and a very badly inefficient one at that.

The only possibly economical ways to ever produce hydrogen will be to use "free" energy from wind, solar, tidal or hydro, and amortizing the necessary infrastructure may well make those processes un-economical.

that is easy insted of it drippin out of tail pipe convet it to steam to clean the windows. chill it or Heat in summer and winter to keep the cars interior cool or warm just like hard floor radiant heating.

"The water has a little electrolyte mixed in, much like your car battery. This allows current to flow through the water, yet lowers the freezing point well below freezing. you may be able to check to what temperature with an electrolyte tester."

There is no reason to expect an electrolyte in the water. If you are using a fuel cell, the electrolyte (or catalyst) is a solid, such as paladium or a polymer, which stays in the cell. If you burn the hydrogen in a heat engine, there would be no point in the exhaust water conducting electricity.

Water vapor wouldn't be a problem, it would mostly dissipate in the air. But I agree with some of the others that hydrogen for cars is a dead end. I believe battery powered electric cars are the way to go.

I can't beleive you even asked this. Within moments of start up a vehicles exhaust system is very warm to hot. Even if you didn't have a freeze situation the moisture would would have to be evacuated from the muffler and catalytic convertor. This would most likely be accomplished by a false bottom in the muffler and cat. convertor with pee holes (a carpenters term for window frame water vents)for drainagge of the accumulated water. So there should never be a time when the engine is running and water is being created that a freeze situation could occur.

Can there be a transport revolution around with so many ideas on alternative energy doing the rounds,as in computers and internet.It is like counting chickens before they are hatched.