"There is actually more hydrogen in a liter of gasoline (116 grams) than there is in a liter of pure liquid hydrogen (71 grams)!"
But the coolest of all is that hydrogen flames are invisible! Hydrogen flames are so energetic that they emit UV radiation! I remember when I was in grade school and tried electrolysis at home. I managed to collect some hydrogen in a test tube, and I ignited it with a match. I heard a loud bang, but no flame. Sound, but no light. That was fascinating.
hydrogen refinery would look same when on fire as when not. - except for the heat wave distortion, plumes of smoke from burning paint, drooping steel gangways, showers of electrical sparks from the shorting electrical system, and workers leaping from the upper levels.
And if the fuel in a hydrogen car decided to burn, everyone in its vicinity will find out in a real hurry - a fire that looks different is still a fire.
Though his point is valid - hydrogen will burn extremely quickly, we used to do these as demonstrations in school. Where a pool of gasoline will burn over a period of time, a tank full of hydrogen will burn almost instantaneously to disastrous effect - forget about rescue, the only sort of "rescue" will be body retrieval of whatever is left.
However, hydrogen will not pool like gasoline. If it doesn't ignite, it will just fly off into space. This mitigates some of the risk (i.e. if there is an accident, a fuel leak will either kill you quickly, or it won't)
I completely agree with the content in this sideshow, except I think he left out a important part of the H2 discussion.
H2 is a complicated/inefficient/explosive way to move energy, but it's very clean (as a energy transfer medium). At the moment, the way H2 is generated is very unclean (using Methane, or using the power from coal and other dirty power sources).
But if the origin of the energy is totally clean (hydroelectric, wind, solar), you can use that energy to break water down, then transfer that hydrogen in to the vehicle. Breaking down water is not so efficient, but it's still clean. I think this is the ideal (maybe dreamlike) goal of the H2 Camp.
"But if the origin of the energy is clean (hydroelectric, wind, solar), you can use that to break water down and then transfer that energy to the car."
Using electrolysis, right? How pure must the water be? One can't use seawater, as that would produce HCl instead of H2, right? Desalination consumes a lot of power, but it may be an option if enough hydroelectric / wind / solar power is generated.
I wonder if one could use the water stored in the ice caps for electrolysis. An enormous source of relatively pure water could perhaps be an economical and scalable source of H2. Just speculating.
It's not that bad; a little math suggests people would still use more water for flushing the toilet than transportation over the average day.
Energy density of 1 kilogram of hydrogen = ~1 US gallon of gas. A gallon of water has ~2/(2+16) * 3.8kg =0.4 kg.
So ~2.4 gallons of water + (ton of energy) ~= 1 gallon of gas.
PS: Bulk fresh water still tends to run at thousandths of a cent per gallon in most areas. But, 14 kilowatt hours desalinates 1000 gallons of seawater so 14 watts per gallon which is a tiny fraction of the energy needed to split water into hydrogen and oxygen.
> PS: Bulk fresh water still tends to run at thousandths of a cent per gallon in most areas.
The marginal price of water in San Jose is around 0.3 cents/gallon. However, the "connection charge" and various taxes and fees end up doubling the "as delivered" cost.
They are probably using desalinization. "Depending on local energy prices, 1,000 gallons of desalinated seawater can cost around $3 or $4." http://www.livescience.com/environment/070625_desalination_m... Even still adding ~1.5 cents per gallon of gas equivalent is not really expensive.
However, the connection charge is just highway robbery if you are really paying that per gallon. They might also be adding the sewer system charges based on your water usage.
PS: The average American uses ~90 gallon /day * 0.3 = 27cents per day * 365 = 100$ / year which is hardly breaking the bank.
For the water bill that I'm looking at, the connection charge (which is determined by the pipe diameter) is $15/month and taxes are about $3. This household is using about 40g/day/person and its monthly cost for the water is about $15.
> However, the connection charge is just highway robbery if you are really paying that per gallon.
San Jose city govt uses services to pay off various folk.
> They might also be adding the sewer system charges based on your water usage.
I just looked - the sewage charge is on the property tax bill.
The "water source" report that they send every year mentions ground and well water. It does not mention desalinization.
Given the low density, it's questionable to me whether it's better to use electricity to make hydrogen and put it in a tank compared to just putting it in a battery in a car. Bypasses the production losses and the low ICE efficiency.
I agree with you entirely - converting clean electricity into a finicky form of transport seems ill-advised. That being said, battery technology has a long way to go before being able to power a car entirely.
For one thing, energy density needs to improvement by an order of magnitude to make mass application useful, and the average lifetime of the battery I would say would have to increase 2-3x. Batteries are expensive to manufacture and the ecological impact of disposal is also extremely high - better to make longer-lasting batteries than cheap crap.
Just saying that "the ecological impact of disposal [of batteries] is also extremely high" without differentiating between battery types is to simplify the issue too much I think. Some batteries are bad to throw away, others are less bad, but you can also recycle batteries.
"Lithium Ion batteries are classified by the federal government as non-hazardous waste and are safe for disposal in the normal municipal waste stream," says Kate Krebs at the National Recycling Coalition. http://bit.ly/wS344
In general, throwing away stuff that isn't naturally occuring in the eco system is often bad, and sometimes too much of something natural can be bad too. But blanket statements that something is bad don't help. The battery system would be replacing something else, like a petrol driven engine, which also has an environmental impact and is much less efficient.
He means that solar and wind power (and other renewable energy sources) represent only a tiny fraction of power generation in the US. Therefore, using them as a justification for the "clean" generation of hydrogen just doesn't make the case.
He is right that they are indeed "rounding errors." The DOE's own data shows that "Wood, black liquor, other wood waste, biogenic municipal solid waste, landfill gas, sludge waste, agriculture byproducts, other biomass, geothermal, solar thermal, photovoltaic energy, and wind" contributed to only 3% of total energy production in the US in 2008. [1]
Precisely. (Thank you for chiming in. I'm the author of the presentation in question, and am completely surprised to find it here on Hacker News nearly two years after publication!)
The best solution seems to be plug-in hybrid cars with batteries. They move the power generation problem from cars to power plants, where nuclear, solar or some unforeseen future technology can handle it. More importantly, you can actually buy them today, and they can fall back on gasoline when exceeding the range of their batteries, so drivers don't have to worry about getting stuck like they do with all-electric cars. If the US automotive fleet were entirely converted to plug-in hybrids, then the remaining demand for gasoline would be small enough to supply with synthetic fuel, which can in principle be made carbon-neutral as well.
In the near term, plug-in hybrids with flex-fuel engines, plus lots and lots of nuclear power plants, followed by space-based solar power satellites in the medium term. Fusion in the long term (defined as "after I'm dead, dammit").
I can't speak for the author - but there is some evidence that, to produce our power needs via wind/tidal means on a large scale (i.e. an appreciable portion of total production) would cause as of yet hard to predict ecological impact. You sap the energy out of your tide and wind and bad juju will happen to your environment.
"Hard to predict" is an understatement. For all we know, extracting energy from wind and waves could counter the recent perceived increase in hurricanes and tropical storms, or it could restore weather patterns to what they were prior to deforestation.
> For all we know, extracting energy from wind and waves could counter the recent perceived increase in hurricanes and tropical storms
The recent trend in hurricanes has been a decrease. (We can spot storms in places that we couldn't look before, but if we look just where we could look before, there's a decrease.)
This is what Don Lancaster at http://www.tinaja.com/h2gas01.asp has been saying for a long time. One quote "Please also note that because of the staggering loss of exergy, use of
electrolysis for bulk hydrogen apps is a really, really dumb thing to do.
It is the equivalent of exchanging two US dollars for one Mexican peso."
One thing I can't stand about the hydrogen debate is how people link it to "fuel cells are bad." Solid Oxide fuel cells happen to be quite economical and successful by using other fuels like propane and gasoline. There are disadvantages with every energy technology, but the trick is using them in the right combination that makes the most sense. No need for unproductive flame wars.
And the quotes from "smart people" are ridiculous. Wow, you quoted someone else (and most likely out of context) to make your point stronger. Good for you. Do you want a cookie?
Other people may have looked at the unfavorable characteristics and conclude "fuel cells are bad." That would be sloppy and stupid.
My message would be that "HYDROGEN fuel cells are bad, especially for automotive use." I like fuel cells in general; my employer has some great work going on with methanol fuel cells.
As far as the quotes being out of context... you've got Google, right there in your toolbar. Look 'em up.
I have no problem with your content (with the exception that you failed to mention which technologies COULD be commercialized rather easily). I believe you gave all accurate information. I just didn't like your presentation.
So some critiques, if I may:
1) Slide 2 - Why? I know you're trying to demonstrate your credibility, but this just seems like bragging. Who cares if you achieved highest honors.
2) Slides 2,6,9,13,14,15,19,22,28,29,37 - waaaaay too verbose. If you came to give a seminar at my school, I would have been drawing stick figures by now. Brevity is key.
3) I still stand by my criticism of your quotes. They add absolutely nothing to your presentation. What are they supposed to accomplish? And I assumed you were giving this talk in front of a group of people...so which toolbar are you referring to...the one on my iphone?
37 comments
[ 1.7 ms ] story [ 84.2 ms ] threadLiquid hydrogen leaks can be ignited by the static spark set off by the leak itself?
Hydrogen flames are not visible (see slide 16: hydrogen refinery would look same when on fire as when not.
Compressed H2 gas or Liq H2 have only about 15% or 30% of the energy-per-gallon as gasoline.
And on and on... Sure casts doubt on feasibility of H2 as a medium for energy storage.
"There is actually more hydrogen in a liter of gasoline (116 grams) than there is in a liter of pure liquid hydrogen (71 grams)!"
But the coolest of all is that hydrogen flames are invisible! Hydrogen flames are so energetic that they emit UV radiation! I remember when I was in grade school and tried electrolysis at home. I managed to collect some hydrogen in a test tube, and I ignited it with a match. I heard a loud bang, but no flame. Sound, but no light. That was fascinating.
Which was done in (yeah, I know) an episode of CSI:Miami: http://csimiami.wetpaint.com/page/207:Grand+Prix
Though, of course, hydrogen is far more exciting.
Though his point is valid - hydrogen will burn extremely quickly, we used to do these as demonstrations in school. Where a pool of gasoline will burn over a period of time, a tank full of hydrogen will burn almost instantaneously to disastrous effect - forget about rescue, the only sort of "rescue" will be body retrieval of whatever is left.
H2 is a complicated/inefficient/explosive way to move energy, but it's very clean (as a energy transfer medium). At the moment, the way H2 is generated is very unclean (using Methane, or using the power from coal and other dirty power sources).
But if the origin of the energy is totally clean (hydroelectric, wind, solar), you can use that energy to break water down, then transfer that hydrogen in to the vehicle. Breaking down water is not so efficient, but it's still clean. I think this is the ideal (maybe dreamlike) goal of the H2 Camp.
Using electrolysis, right? How pure must the water be? One can't use seawater, as that would produce HCl instead of H2, right? Desalination consumes a lot of power, but it may be an option if enough hydroelectric / wind / solar power is generated.
I wonder if one could use the water stored in the ice caps for electrolysis. An enormous source of relatively pure water could perhaps be an economical and scalable source of H2. Just speculating.
Energy density of 1 kilogram of hydrogen = ~1 US gallon of gas. A gallon of water has ~2/(2+16) * 3.8kg =0.4 kg.
So ~2.4 gallons of water + (ton of energy) ~= 1 gallon of gas.
PS: Bulk fresh water still tends to run at thousandths of a cent per gallon in most areas. But, 14 kilowatt hours desalinates 1000 gallons of seawater so 14 watts per gallon which is a tiny fraction of the energy needed to split water into hydrogen and oxygen.
The marginal price of water in San Jose is around 0.3 cents/gallon. However, the "connection charge" and various taxes and fees end up doubling the "as delivered" cost.
However, the connection charge is just highway robbery if you are really paying that per gallon. They might also be adding the sewer system charges based on your water usage.
PS: The average American uses ~90 gallon /day * 0.3 = 27cents per day * 365 = 100$ / year which is hardly breaking the bank.
They say that they're not.
> However, the connection charge is just highway robbery if you are really paying that per gallon.
San Jose city govt uses services to pay off various folk.
> They might also be adding the sewer system charges based on your water usage.
I just looked - the sewage charge is on the property tax bill.
The "water source" report that they send every year mentions ground and well water. It does not mention desalinization.
For one thing, energy density needs to improvement by an order of magnitude to make mass application useful, and the average lifetime of the battery I would say would have to increase 2-3x. Batteries are expensive to manufacture and the ecological impact of disposal is also extremely high - better to make longer-lasting batteries than cheap crap.
"Lithium Ion batteries are classified by the federal government as non-hazardous waste and are safe for disposal in the normal municipal waste stream," says Kate Krebs at the National Recycling Coalition. http://bit.ly/wS344
In general, throwing away stuff that isn't naturally occuring in the eco system is often bad, and sometimes too much of something natural can be bad too. But blanket statements that something is bad don't help. The battery system would be replacing something else, like a petrol driven engine, which also has an environmental impact and is much less efficient.
Is he saying that they are currently just very limited compared to other energy generation methods in use, or that they're completely unviable?
He is right that they are indeed "rounding errors." The DOE's own data shows that "Wood, black liquor, other wood waste, biogenic municipal solid waste, landfill gas, sludge waste, agriculture byproducts, other biomass, geothermal, solar thermal, photovoltaic energy, and wind" contributed to only 3% of total energy production in the US in 2008. [1]
[1] http://www.eia.doe.gov/cneaf/electricity/epm/table1_1.html
Stay away from my waves!
The recent trend in hurricanes has been a decrease. (We can spot storms in places that we couldn't look before, but if we look just where we could look before, there's a decrease.)
The middle of the 20th century was far worse.
And the quotes from "smart people" are ridiculous. Wow, you quoted someone else (and most likely out of context) to make your point stronger. Good for you. Do you want a cookie?
Other people may have looked at the unfavorable characteristics and conclude "fuel cells are bad." That would be sloppy and stupid.
My message would be that "HYDROGEN fuel cells are bad, especially for automotive use." I like fuel cells in general; my employer has some great work going on with methanol fuel cells.
As far as the quotes being out of context... you've got Google, right there in your toolbar. Look 'em up.
So some critiques, if I may:
1) Slide 2 - Why? I know you're trying to demonstrate your credibility, but this just seems like bragging. Who cares if you achieved highest honors.
2) Slides 2,6,9,13,14,15,19,22,28,29,37 - waaaaay too verbose. If you came to give a seminar at my school, I would have been drawing stick figures by now. Brevity is key.
3) I still stand by my criticism of your quotes. They add absolutely nothing to your presentation. What are they supposed to accomplish? And I assumed you were giving this talk in front of a group of people...so which toolbar are you referring to...the one on my iphone?
1. You can't win
2. You can't even break even"