Every once in a while I get asked the question about the connection between hydrogen cars and greenhouse gases, so I thought I would address the issue here. Jeff from Fallbrook, California sent in the following question:
Jeff: “Since water vapor is the major greenhouse gas causing global warming, how would a hydrogen car with emissions of water vapor be considered green?”
Hydro Kevin: Water vapor is the major ingredient in greenhouse gases, but it is also the major ingredient in clouds and in turn rain as well. The role of water vapor in greenhouse gases and in turn the greenhouse effect is one that is controversial and heavily debated by atmospheric scientists.
Many scientists subscribed to the theory of the positive feedback loop in which more water vapor is absorbed into the higher levels of the atmosphere and in turn absorb more heat and have a warming effect. But, scientists also have a hard time analyzing and simulating the formation of clouds that have a cooling effect on the planet.
According to the National Oceanic and Atmospheric Association (NOAA), “As water vapor increases in the atmosphere, more of it will eventually also condense into clouds, which are more able to reflect incoming solar radiation (thus allowing less energy to reach the Earth’s surface and heat it up).”
In regard to fuel cell manufacturers there is research currently being conducted to recycle the water vapor for use back into the fuel cell. In addition, water vapor doesn’t have to come out the tailpipe of a hydrogen car. The manufacturers could design a system where the water vapor is cooled and ported into a holding tank.
The water in this holding tank could then be disposed of or it could be put to further use. One use would be to recycle the water through an electrolysis system, create hydrogen and run it through the fuel cell again. In this kind of closed loop system, the issue of greenhouse gases does not even arise.
The Union of Concerned Scientists also have weighed in on this issue as well.
Hi,
I am a bit concerned that Water vapour may makes matters worse
(a) Is it possible to break up water vapour into Hydrogen and Oxygen onboard the vehicle, using say Solar energy ?
(b) Would this result in 100 % elimination of water vapour
?
(c) would it work in cold temperatures?
(d) Would it be possible to convert water vapour into liquidWater
?
Sujay
The water vapor doesn’t necessarily have to come out of the tailpipes of the vehicles. The water vapor can be recycled and run through the fuel cell again and it also can be collected for disposal as liquid water later.
Where do you get your Hydrogen? Isn’t it produced by electrolysis of Water – by Electricity which in the US is predominantly produced by burning COAL, which is mined from the earth releasing Methane?
How much space and weight does a condensor add to the vehicle? Does it really make sense to add this weight to a vehicle, thus making it consume more fuel to get around? The answer to fuel efficiency is to move less weight around not more.
Over 90-percent of hydrogen produced today comes from steam reforming natural gas. Of course the ideal would be to create hydrogen from water using renewable resources like solar or wind power.