Am I the only one that's ever thought of this?

[LotC]

Say in 20 years that everything is perfect and we have transitioned from dirty internal combustion engines to sparkly clean hydrogen fuel cells for our transportation needs. Instead of vehicles belching out CO2, particulates, and other assorted pollutants, they instead emit clean water vapour.

What would the effect be of hundreds of thousands of cars in an urban area spewing water vapour into the air? It's known that water vapour is a very effective greenhouse gas. I doubt that it would make it high enough into the atmosphere to have much of an effect this way, but wouldn't it tend to produce bigger clouds and therefore more rain downwind from the cities?

I'm looking at this from the perspective of there being too many people. Would hydrogen power really save us, or would we just be trading one problem for another?

[Space05us]

Compressed air

http://www.theaircar.com/acf/

[Proteus_MST]

Look at the massive amounts of water vapor that cooling towers produce. AFAIK the widespread use of cooling towers hasn´t lead to large scale alterations of the meterological system in the areas around them (only maybe small scale alterations in the direct vicinity, like for example giant snowflakes).
And I assume that the total amount of water vapor produced by hydrogen fuel cell cars will me much smaller compared to the total amount of water vapor produced by cooling towers (due to the efficiency of the fuel cells)

[Kuciwalker]

What would the effect be of hundreds of thousands of cars in an urban area spewing water vapour into the air? It's known that water vapour is a very effective greenhouse gas. I doubt that it would make it high enough into the atmosphere to have much of an effect this way, but wouldn't it tend to produce bigger clouds and therefore more rain downwind from the cities?

The water already has to come from somewhere. The problematic step with using petroleum (and coal) as fuel isn't burning it in cars, it's extracting it from the ground. That represents taking carbon that was sequestered outside the normal carbon cycle, and reintroducing it into said cycle. One part of that cycle is CO2 in the atmosphere - so by increasing to total amount of carbon in the cycle, you increase the amount of CO2 in the atmosphere.

Hydrogen fuel cells would presumably take hydrogen from water, so it's not increasing the total amount of water in the water cycle.

[LotC]

Originally posted by Proteus_MST
Look at the massive amounts of water vapor that cooling towers produce. AFAIK the widespread use of cooling towers hasn´t lead to large scale alterations of the meterological system in the areas around them (only maybe small scale alterations in the direct vicinity, like for example giant snowflakes).
And I assume that the total amount of water vapor produced by hydrogen fuel cell cars will me much smaller compared to the total amount of water vapor produced by cooling towers (due to the efficiency of the fuel cells)

A very good point regarding cooling towers. I wonder just how much H2O emissions cooling towers produce compared to hundreds of thousands or even millions of cars. Also keep in mind that emissions from cars would be spread around the city compared to cooling towers.

Take a look at 2 cities. First, Vancouver (it's where I live so I know the pollution patterns well). To the east of the city, with a prevailing westerly wind, lies the Fraser Valley. As bad as the smog gets in the city, it's nothing compared to 70 miles east of it, where there are regularly air quality warnings in the summer. The smog gets trapped between the mountains and just sits there with nowhere to go. Instead of air quality warnings, would they be looking at humidex warnings?

Now how about LA? Same problem, but way more cars and the smog doesn't even really go anywhere; it just hangs over the city and accumulates day after day. I suspect this would cause localized rain patterns to change.

[LotC]

Originally posted by Kuciwalker

What would the effect be of hundreds of thousands of cars in an urban area spewing water vapour into the air? It's known that water vapour is a very effective greenhouse gas. I doubt that it would make it high enough into the atmosphere to have much of an effect this way, but wouldn't it tend to produce bigger clouds and therefore more rain downwind from the cities?

The water already has to come from somewhere. The problematic step with using petroleum (and coal) as fuel isn't burning it in cars, it's extracting it from the ground. That represents taking carbon that was sequestered outside the normal carbon cycle, and reintroducing it into said cycle. One part of that cycle is CO2 in the atmosphere - so by increasing to total amount of carbon in the cycle, you increase the amount of CO2 in the atmosphere.

Hydrogen fuel cells would presumably take hydrogen from water, so it's not increasing the total amount of water in the water cycle.

That is true. However, it would be concentrating a large amount of water vapour in one area. Although we wouldn't be changing the total amount of water in the water cycle, we would be changing the location of the water in addition to the phase on a not insignificant level.

[Winston]

Well, I'm buying umbrella stocks in the morning.

Thanks!

[LotC]

Originally posted by Winston
Well, I'm buying umbrella stocks in the morning.

Thanks!

You're a man ahead of your time.

[Theben]

Most likely future cars will be electric. The focus will be on the supply end, as well as engine performance.

[Zkribbler]

Re: Am I the only one that's ever thought of this?

Originally posted by LotC
... It's known that water vapour is a very effective greenhouse gas...

About 1/20 the effect of CO2,
and a LOT less than methane.

[Kuciwalker]

Originally posted by Theben
Most likely future cars will be electric. The focus will be on the supply end, as well as engine performance.

Um, hydrogen fuel-cell powered cars are electric. A fuel cell is just an exotic battery.

[LotC]

Re: Re: Am I the only one that's ever thought of this?

Originally posted by Zkribbler


About 1/20 the effect of CO2,
and a LOT less than methane.

Please keep your facts out of my unpleasant future scenario.

Let's say for the sake of doom that we harness the power of cow farts to make the hydrogen.

If anyone is going to sh!t in this thread it's me. *splurchhhh*

[Theben]

Originally posted by Kuciwalker

Um, hydrogen fuel-cell powered cars are electric. A fuel cell is just an exotic battery.

Whoops. That's what happens when you skim.

[Adalbertus]

Please don't forget that fuel cells are not a "source" of energy but a storage. The hydrogen they consume has to be generated by electrolysis. They have only an advantage if they are energetically more efficient than usual motors, or if electricity is produced with low CO2 emissions (of course not nuclear!)

There are already two well-known parties in Germany who are convinced that Germany's entire energy consumption can be supplied by invisible windmills.

[notyoueither]

Re: Re: Re: Am I the only one that's ever thought of this?

Originally posted by LotC


Please keep your facts out of my unpleasant future scenario.

Let's say for the sake of doom that we harness the power of cow farts to make the hydrogen.

If anyone is going to sh!t in this thread it's me. *splurchhhh*

Said like a good prairie boy.