4 ms·

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/explosi

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.

TriinT 17y ago
"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.
- Retric 17y ago
  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.
  - anamax 17y ago
    > 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.
    - Retric 17y ago
      They are probably using desalinization. "Depending on local energy prices, 1,000 gallons of desalinated seawater can cost around $3 or $4." http://www.livescience.com/environment/070625_desalination_membranes.html http://www.livescience.com/environment/070625_desalination_m... Even still adding ~1.5 cents per gallon of gas equivalent is not really expensive. However, the connection charge is just highway robbery if you are really paying that per gallon. They might also be adding the sewer system charges based on your water usage. PS: The average American uses ~90 gallon /day * 0.3 = 27cents per day * 365 = 100$ / year which is hardly breaking the bank.
      - anamax 17y ago
        > They are probably using desalinization. They say that they're not.
      - anamax 17y ago
        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.
lutorm 17y ago
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.
- potatolicious 17y ago
  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.
  - bjelkeman-again 17y ago
    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 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.
    - likpok 17y ago
      Furthermore, lead-acid (car) batteries are extremely easy to recycle (and are valuable; you almost always get a trade-in discount).

TriinT 17y ago

"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.

Retric 17y ago
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.
- anamax 17y ago
  > 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.
  - Retric 17y ago
    They are probably using desalinization. "Depending on local energy prices, 1,000 gallons of desalinated seawater can cost around $3 or $4." http://www.livescience.com/environment/070625_desalination_membranes.html http://www.livescience.com/environment/070625_desalination_m... Even still adding ~1.5 cents per gallon of gas equivalent is not really expensive. However, the connection charge is just highway robbery if you are really paying that per gallon. They might also be adding the sewer system charges based on your water usage. PS: The average American uses ~90 gallon /day * 0.3 = 27cents per day * 365 = 100$ / year which is hardly breaking the bank.
    - anamax 17y ago
      > They are probably using desalinization. They say that they're not.
    - anamax 17y ago
      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.

lutorm 17y ago

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.

potatolicious 17y ago
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.
- bjelkeman-again 17y ago
  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 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.
  - likpok 17y ago
    Furthermore, lead-acid (car) batteries are extremely easy to recycle (and are valuable; you almost always get a trade-in discount).