It seems that hydrogen cell technology may not be the enviromentalist's dream after all.
Researchers at the California Institute of Technology published a report today in the journal Science saying that if hydrogen replaced fossil fuels to run everything from cars to power plants, large amounts of hydrogen would drift into the stratosphere as a result of leakage and indirectly cause increased depletion of the ozone*. [full story]I still think this technology is viable. I do agree, however, that "hydrogen's impact on ozone destruction should be considered when gauging the potential environmental downside of a hydrogen-fuel economy." Note that they did not say the emissions** from using such technology would be effecting the environment. I am sure it would not take too much thought to figure out how to refuel the cells without allowing the hydrogen to escape into the atmosphere or to put enough safeguards in place to detect any leakage in the supply lines.
attribution: Jaboobie
*I often wondered when I lived in Dallas and we regularly had "Ozone Alert" days, where they cut the public transportation fares in half to get people to ride the train or bus on such days due to the amount of ozone hanging over the city, how could we have an ozone layer problem when there seemed to be so much extra ozone hanging around. I just did not know why, if it was near the top of the atmosphere (which should mean it was lighter than any other element in the atmosphere), that the ozone hung near the ground instead of floating up and filling up any holes that everyone was always worrying about in the ozone layer. Of course, I am sure some scientist could easily explain this to my satisfaction, but it sure did and still does boggle my mind why it was and still is such a problem.
**From the report I saw about GM's hydrogen cell vehicles, it seems the only by-product or emission from the vehicle is pure water.
Posted by Tiger at June 13, 2003 05:03 PMThe thing that no one mentions in the environmental debate is how to obtain the hydrogen for the fuel cells in the first place. Hydrogen is the most abundant element on earth but it is almost never seen alone. Usually it is found in the form of either water (hydrogen dioxide) or in the forms of hydrocarbons like, yup you guessed it, oil.
Therefore, the two major ways of getting pure hydrogen for the fuel cells is by splitting the hydrogen off from the water or from the hydrocarbons. Splitting it off of water is a pretty straightforward process known as electrolysis. However, this process is incredibly inefficient, requiring many times the amount of input energy as the hydrogen gives in return. Splitting it off of the hydrocarbons is much more efficient, however, after it is split off what are you left with? The very same greenhouse gases you would be left with if you combusted the hydrocarbons in a normal internal combustion engine.
In effect, these hydrogen fuel cells aren't reducing the level of pollution, they are simply redistributing where the pollution occurs. Instead of having nitric emissions and greenhouse gases coming out of the tailpipes of the vehicles we will be having these emissions being released from hydrogen refinement plants. Or if we go the electrolysis route, we will have a lot more nuclear waste or sulfuric emissions courtesy of the massive amounts of energy required to provide the required amount of pure hydrogen.
It is something to think about.
Posted by: AstreaEdge at June 13, 2003 05:20 PM