Possible Problem With Hydrogen Fuel Cell Vehicles?

So I have been thinking about this the past couple days about hydrogen fuel cell vehicles. O.k, the only exhaust that comes from these vehicles is water vapor? ( At least I think so). That is all well and good but I have been wondering about the implications of all this water vapor being exhausted. Suppose hydrogen fuel cells took the place of all the gasoline engines in the United States. Now, would all this water vapor being exhausted create adverse weather (increase in rain, etc.)?

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Well, it will contribute to the greenhouse effect. Gaseous water has a greenhouse factor of around 0.1. This means that water vapour has 0.1 times the greenhouse effect of carbon dioxide. Some of the other gases emitted by cars at the moment have greenhouse factors in the hundreds or even thousands. Increasing the concentration of water vapour in the atmosphere would increase the overall greenhouse effect, but the loss of the other chemicals emitted by cars at the moment would more than cancel out the increase thousands of times over.

A lot of water vapour would also make an area more humid. At the moment, large cities have photochemical smogs caused by exhaust fumes and the chemicals contained in them. They are caused by strong sunlight hitting a 'cloud' of these chemicals. These smogs would reduce dramatically, but the area would become more humid due to the extra water vapour.

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There is also another problem here... How do we get Oxygen and Hydrogen? Split water with electricity...but then where do we get the electricity from? You could say from another H2O engine but that jut passes the problem down one link, at the end of the day we need electricity otherwise the hydrogen and oxygen simply become like batteries, STORING the energy from the national grid to be released later, and at the moment the vast majority of grid electricity comes from gas, coal, or oil.

And the way i look at it you could actually store the excess water from the exhaust and simply re-use it by splitting it again and putting it back in the engine so that way there would be no exhaust at all, provided you could find an easy and environmentally free way to generate the electricity needed.

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I could say the same of fossil fuels; where do we get the power to drill/pump them?

Really, we can't have infinite energy but, I suppose, won't it be better to split water into fuel cells using power from hydroelectric stations, windmills, geothermal plants and solar cells instead of fossil fuels?

Anyway, I don't think we can "recycle" water for power within the same vehicle. I mean, we can't just have a splitter waiting by the exhaust... unless that same vehicle has solar cells or a nuclear reactor within. So... it's kinda feasible for ships... or trucks, but I don't think we'd have a fuel cell and water splitter combo in cars anytime soon.

Now, about its side effects, I'm pretty sure there'd be changes on the climate. I mean, we're transporting water here; there's bound to be changes in the water cycle. Then again, there may be insignificant ones, since we've been moving water around (along pipes, open canals, down drains, in gutters or on streets) for a long time now. Just my two cents

 

 

 

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Considering that you probably produce plenty of water vapor just by making tea, much less cooking anything else, I don't think there would be any significant difference in climate/weather. The amount of water vapor would be negligible compared to the amounts that even produced naturally in nature.

The energy used to create the fuel cells could easily come from renewable resources. All that it requires is proper investment. Wind, solar, and tidal/wave energy are all good sources, but I personally think that we should start looking at increasing our use of nuclear energy. With the proper safeguards it is quite safe. Also, once the cost of sending objects into space is brought down (very possible within the next couple decades), then we will have a good way of disposing of the nuclear waste created. Launching nuclear waste at the sun seems a good way to get rid of it.

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Well it's not like you gather pure hydrogen and pure oxygen and then produce water that was never there in the first place. You use water, you end up with water, right?

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Actually, you very often don't start with water. Oxygen and hydrogen are often biproducts of other chemical process, and can be collected and sold on. This is a form of recycling I suppose. The waste chemicals produced can often be used in another process, and therefore are collected and shipped off to whoever needs them.

However, this rarely produces enough of a chemical to satisfy the world's needs. There are therefore methods of producing common chemicals. Oxygen and hydrogen can be gathered from pure water through electrolysis, but the process is very expensive, requires a lot of energy and the water needs to be very pure.

The preferred method of 'producing' pure oxygen is from liquefied air. The liquid air is fractionally distilled to produce nitrogen gas, and often leaves the oxygen in a liquid state to be transferred to wherever it is needed. Obviously here you didn't start with water.

Hydrogen is often gathered by reacting steam with methane at high temperatures and pressures (again, making the process expensive). This process produces three times as much hydrogen as was in the water (as you get 2 hydrogen molecules from the methane), so will ultimately result in more water than was initially used. The process also produces poisonous carbon monoxide gas, which needs to either be reacted with another chemical and turned into something useful and less deadly, or just gets released into the atmosphere, which makes it only marginally better than a car at the moment.

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