Mercedes fuel cell car - one step closer

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Comments

  • Reply 41 of 48
    matsumatsu Posts: 6,558member
    I dunno, producing the number of cars we make every year must have serious environmental drawbacks. The tooling; energy; materials (their extraction, and processing); transportation; and storage. The overall network required at each step of mass production has a HUGE environmental impact. Then you must factor the costs of discarding/recycling older vehicles.



    At the same time, the fuel efficiency/emissions gains from one car to the next have been incremental. Over 50 years that has produced some wonderfully efficient autos, but those 50 years have covered a lot of models. That would make for at least 5-6 major redesigns of a vehicle in addition to at least as many mid-life updates (to engine/trim/running gear). The current pace of new model redesigns is even greater, with some models recieving a major redesign every 4-5 years. I think anyone who has owned 10+ vehicles over 50 years time has done more to harm the environment than help it regardless of how efficient each of the vehicles became.



    Someone who keeps a 10 year old car in perfect running condition, might be doing more of a service to the environment than you think.



    As to the leaded fuel problem, that's no problem. We got rid of lead a long time ago now. Fuel additives should have been done away with too. You don't need them to run unleaded in a leaded engine. All you need for most vehicles is a retune (a little timing adjustment) and hardened valve seats. Modern fuels are quite good, and the vehicles I've seen (so modified) run great.



    I didn't say old clunkers spewing black/blue smoke and dripping oil all over the place. I said good running condition.
  • Reply 42 of 48
    cdhostagecdhostage Posts: 1,038member
    Perhaps a good plan is thus: keep everything the waty it is. By the time the oil fileds arre dired up, someone will have found a way to make large quantities of antimatter.



    Here's an idea, much bette than transmitting solar electricity via microwaves or even waiting millions of years for oil or coal to develop or even the new H2-making algea.



    Make a very, very large solar collector. You can have it in space or on the Moon. Use the electricity from it to power an accelerator. This is 2002 tech, I believe that its current implementation will be refined. Fermilab at Chicago makes 1.5 nanograms a year, most of which is used in experiments.



    This idea is inefficient as hell, but let's run with it.

    Anywhoo, let's say that you build an orbiting antimatter production platform. Let's be pessimistic in all our calculations and be happily surprised later (it's how I do my accounting ) . The solar energy in space is heavier than on earth, but let's ignore that (being pessimistic).

    A commercial solar collector can produce a little less than 100 watts per square meter at high noon at the equator. I assume there are better collectors available, but we're being pessimistic. An orbiting sattalite will always be intentionally turned toward the Sun, so except when it's behind the Earth or Moon, it will be getting full power.

    A collection of collectors will be, say, 10 kilometers on a side. 100 square kilometers or 10,000,000,000 square meters.

    1,000,000,000,000 watts of solar power.

    Let's assume that after all that electricity gets to the station on the ring of the accelerator (it will be on the night side, 9.9 kilometers in diameter), most of its energy has been dissipated (99%).

    10,000,000,000 watts of useful power.

    Let's assume that the accelerator tech is just as wasteful, and wastes 99% of the energy in the creation of antimatter fuel.

    100,000,000 watts of power made into antimatter constantly.

    Another 99% wasted in getting it down to Earth in useful fashion and distributing it where it's needed - perhaps to individual neighborhood electricity networks and automobile fillup stations.

    1,000,000 watts of power available most of the time from a single orbiting power station.



    A large nuclear power plant generates 1000 MW, or

    1,000,000 watts of power.



    <after much searching>

    I can't find the electricity usage of a large city, like New York. I've found that a 400 MW generator feeds 1,000 homes, so

    400,000 / 1,000 = 400 watts average usage

    But that's by a home. Industry and cmmercial buildings not consdiered.

    Let alone cars.

    I don't know how many of those big nukes can power say NYC.
  • Reply 43 of 48
    skipjackskipjack Posts: 263member
    <strong>A commercial solar collector can produce a little less than 100 watts per square meter at high noon at the equator.</strong>



    You don't need to be pessimistic. This seems a bit low to me, especially at high noon at the equator. Anyway, in discussions of this sort, it is best to use units of energy (watt-hours) rather than a rate of energy production.



    Are you saying we can manufacture anti-matter, transport the anti-matter to earth, combine it with matter, and collect the resultant energy? You don't explicitly state your plan or give references.



    <strong>A large nuclear power plant generates 1000 MW, or 1,000,000 watts of power.</strong>



    And if such a nuclear power plant produces 1,000,000,000 watts, would you still say the solar collection station is a reasonable pursuit?
  • Reply 44 of 48
    cdhostagecdhostage Posts: 1,038member
    Well my real point is that EVERY SINGLE ENERGY SOURCE (except nuclear) is simply a way of storing solar energy.



    What better way than to use up the stuff that we have, and then switch to the most dense form of energy available? Unless someone makes a perfect mirror and you can store 100 quadrillion gamma ray photons in a jar, releasing a million at a tim to power your machines.





    The antimatter idea really applies best to spaceships - the problem with chemical rockets is that you ned to lug around the fuel with youl If your fuel (hydrogen and antihydrogen) only weighs a couple grams, then you only need enough energy to carry you and you cargo. Much better.





    Of course, this is all moot if someone discovers how to turn matter driectly to energy. There's no need for antimatter then - just carry a converter in our pocket and it will suplly everythigng you could possibly need. Except making more matter, which is hard.
  • Reply 45 of 48
    pfflampfflam Posts: 5,053member
    the future: we have now been able to slow teh speed of light to a crawl, even stop it really. the future will have spaceships that harvest sunlight and store it in transferable tanks that can deliver it to earth . . . .yes? no? <img src="graemlins/hmmm.gif" border="0" alt="[Hmmm]" />
  • Reply 46 of 48
    cdhostagecdhostage Posts: 1,038member
    I imagine the l light-storage idea is even more dangerous than antimatter. Orr not. Either way, if the containment fails, you can sterilize a planet easily.



    Lessee... do you think a ton of antimatter in a thousand little containers, all opened at the same time, would sterilize the place? Prolly.



    Or 100 tons, just exposed to matter anywhere near Earth.



    The light-bubble idea is a little less dangerous perhaps. You can surround a light bubble with a whole lot of armor, and unless the whole thing cracks, the light is contained. An antimatter core just needs a loss of power for a second....
  • Reply 47 of 48
    cdhostagecdhostage Posts: 1,038member
    I tried to look this up but I can't find it.



    Does anyone know the energy density of matter? I mean, combine a half gram of H and the same of -H and how much bang do you get?



    I suppose it follows the equation E = mc2, but I don't know what units to use. Is the energy in Newtons, is the mass in grams, is the speed of light in meters/sec?



    I think I read the answer in Stephen Hawking's Universe in a Nutshell, but I don't know where my cpy is.
  • Reply 48 of 48
    skipjackskipjack Posts: 263member
    [quote]Originally posted by cdhostage:

    <strong>Well my real point is that EVERY SINGLE ENERGY SOURCE (except nuclear) is simply a way of storing solar energy.</strong><hr></blockquote>



    So, noting that use of solar energy (including direct conversion, wind, tides, and hydroelectric) will never supply more than 25% (to be generous, including savings by conservation), we are simply depleting the solar energy accumulated by the earth over millions of years. Wouldn't you say that the earth, overall, is relatively efficient at collecting solar energy to sustain life?



    We need to be like the earth, as far as solar utilization goes. We need distributed collection and generation (e.g., water heating and photovoltaic panels on individual houses and businesses) rather than large scale solar facilities.
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