Hydrogen power -- problems with water pollution?

[Dak]

Hydrogen power is often lauded as a 'clean' energy storage medium, as it only 'pollutes' water -- as long as the power stations that generate the electricity required to split hydrogen from water are clean, then the whole process becomes clean.

 

For things like cars, hydrogen would certainly seem to be cleaner than petrol/diesel/etc. however, what would actually be the effects of thousands of cars exhausting water vapour in a city?

 

I'm not saying that it would contribute to global warming or anything, but H2O is a powerful greenhouse gas... would all that water vapour increase the average air temperature in a city? would the increased air humidity encourage damp-rot? make it harder to dry your cloths? change the local flaura to those more suited to damp conditions?

 

tbh, i'm not sure how quickly the water would come out of the air and just dribble away down the drains. would you hardly notice the difference, or would it be constantly misty around conjested roads?

 

at the very least, when it's cold i can see there being a problem with increased (black?) ice due to the steam comming out of the backs of all the cars, settling and then freezing.

 

so yeah, what would the problems be if all cars ran on hydrogen and exhaled steam? would the steam have to be captured by the car, cooled into water, and then dumped down the drain, or would it not matter if the cars 'polluted' steam/water vapour?

[Cap'n Refsmmat]

You could easily capture the water exhaust and mount a water fountain in the dashboard.

[dfa327]

Why waste? I'd envision a closed system. You fill up the car once with water. Most likely at the factory even to keep it pure. Then you plug it in to your house or use sunlight to get electricity. Then apply the electricity to break down the water in to Hydrogen and Oxygen. Which you'd then store in to some new metal hybrid. (Lithium based is the latest today for Hydrogen) Then use it when needed to get back what you started with. Zero emission car:)

[Dak]

that means that you'd have a car full of H2 and O2?

 

I wouldn't like to see that crash! BOOM!!!

[SkepticLance]

Cars running on petrol and diesel already pump out vast amounts of water vapour. Hydrogen power will pump out more, sure, but I seriously doubt it will have any effect on global warming. And lets face it, many of our cities are already frantically involved in the process of recycling water. Vapour rolls in, rain comes down, streets get washed, more vapour rolls in etc.

 

The amount of water vapour coming off the oceans makes any human attempt to increase it look utterly trivial.

[YT2095]

especially when you consider the Hydrogen comes from existing water in the 1`st place, there`s no net gain of water anywhere

[Dak]

I'm not saying that it would contribute to global warming or anything

 

 

however, could they, locally, affect the concentration of water in the ground-level-air an appreciable amount? think a million kettles, all steaming, and imagine how soggy and hot everything would get

 

or, does anyone know roughly at what rate they'd exhaust water? are we talking the exhaust steaming like a kettle, or more/less?

 

what about incomplete combustion of the hydrogen? wouldn't that be some H₃O⁺ that gets formed?

 

so...... would the exhaust steam be acidic?

[oren tal]

What about power plant that base on fusion of Hydrogen to Helium?