Questions about a Hydrogen Economy; Scientific American

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The discussion centers on the concept of a "hydrogen economy," highlighting the misconception that hydrogen serves as a direct energy source like fossil fuels. Participants emphasize that hydrogen production requires more energy than it yields, often relying on fossil fuels or coal, which raises environmental concerns. The potential for nuclear energy to contribute to cleaner hydrogen production is noted as a preferable alternative. There is a consensus that while hydrogen can be an energy carrier, significant advancements in production technology and infrastructure are necessary for it to be a viable solution. Overall, the dialogue reflects skepticism about the feasibility of transitioning to a hydrogen economy without addressing underlying energy production challenges.
  • #361
I'm not sure what the basis is for their claim, but I imagine that they are talking about the hidden energy costs in the materials used and the construction of fuel cells. Presumably this hidden energy is indirectly related to price. I just checked and found a price of about $10,000 per KW for hydrogen fuel cell stacks. http://www.fuelcellstore.com/cgi-bin/fuelweb/view=Item/cat=31/product=869

The BMW is rated at 260HP which is about 194KW.

How much of the relatively high cost of fuel cells is ultimately representative of the hidden energy of production? Also, what is the lifetime of the fuel cells and how are they recycled?
 
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  • #362
The world's hydrogen fueling stations
http://www.fuelcells.org/info/charts/h2fuelingstations.pdf
 
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  • #363
First Analysis of the Water Requirements of a Hydrogen Economy

...Each of the energy choices we can make, in terms of fuels and technologies, has its own tradeoffs associated with it,” Webber said. “Hydrogen, just like ethanol, wind, solar, or other alternative choices, has many merits, but also has some important impacts to keep in mind, as this paper tries to suggest. I would encourage the continuation of research into hydrogen production as part of a comprehensive basket of approaches that are considered for managing the transition into the green energy era. But, because of some of the unexpected impacts—for example on water resources—it seems premature to determine that hydrogen is the answer we should pursue at the exclusion of other options.” [continued]
http://www.physorg.com/news111926048.html

The point missed is that electrolysis is likely not the path to a hydrogen economy.
 
  • #365
Yes, seawater is plenty enough. edit: Perhaps the salt concentrations are too high and the resulting in maintenance issues make it cost prohibitive?

Also, I was thinking that this is a legitimate concern if using hydrogen from biomass that derives its hydrogen from fresh water. So, given that fresh water resources will grow [and are quickly growing] increasingly valuable, saltwater based biomass may be the best option for sourcing hydrogen; and for ethanol or biodiesel that is for distributed use, for that matter. In closed systems the water can be recovered after combustion.
 
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  • #366
Woohoo! Today when I proposed a hydrogen powered system as a solution to a unique industrial problem, by the time that the owners realized that I was serious and that we really can do this, they were bouncing off the walls.

Yay! I get to design my first hydrogen powered system.
 
  • #367
The hydrogen economy is the goal. The cheapest source of the energy to produce hydrogen from water is nuclear. Some engineer should be trying to figure out how to crack water from the heat generated by this energy source. Electrical generation of H2 and back to mechanical energy is use is too inefficient. The problem with H2 is it carries too little energy per unit wt.

Until this can be solved, we should be looking to make methane from hydrogen and CO2 with the energy from the nuclear energy source.

One idea that nobody seems to mention is getting rid of nuclear waste by jettison to the sun. I know we entered a treaty to ban delivery to the moon, but the sun certainly won't suffer.
 

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