Slashdot Mirror


Crunching the Numbers on a Hydrogen Economy

mattnyc99 writes "In its new cover story, 'The Truth About Hydrogen,' Popular Mechanics magazine takes a close look at how close the United States is to powering its homes, cars and economy with hydrogen — including a calculation of where all the hydrogen would come from to meet President Bush's demands. Interesting that they break down the future of hydropower not by its advantages but by its challenges: production, storage, distribution and use."

9 of 396 comments (clear)

  1. Electricity + Water by dsginter · · Score: 5, Interesting

    With all the problems that hydrogen has, a good stop gap would come with the advent of an affordable fuel cell. With a fuel cell in each house, you could essentially generate hydrogen from water and electricity at night when the power plants are idling in inefficient speeds. During the day, you could do the opposite and generate electricity from the hydrogen generated the previous night. This would work well for shaving energy consumption during peak levels. With discounts for off-peak electricity, this sort of system could pay for itself while providing backup generator services as a side effect.

    Then again, so would a huge flywheel or a bunch of batteries.

    --
    More
    1. Re:Electricity + Water by Anonymous Coward · · Score: 5, Informative

      With a fuel cell in each house, you could essentially generate hydrogen from water and electricity at night when the power plants are idling in inefficient speeds. During the day, you could do the opposite and generate electricity from the hydrogen generated the previous night.

      Or you could do what most people do when they want hydrogen, heat a hydrocarbon with steam. It is a hell of a lot cheaper than electrolysis! In fact, most fuel cells use some sort of hydrocarbon reforming to get their hydrogen. Unless you store hydrogen as a liquid, its energy density is just too low for any reasonable fuel tank.

    2. Re:Electricity + Water by voidptr · · Score: 5, Funny

      You know what makes a good hydrogen carrier?

      Carbon. Link 8 carbons or so in a chain, and populate the remaining bonds with Hydrogen. It forms a stable, energy dense, easily transportable liquid. As an added bonus, you don't need to do any additional processing to use it in that state, just burn it in your existing internal combustion engine.

      --
      This .sig for unofficial government use only. Official use subject to $500 fine.
  2. You keep using that word. by tdemark · · Score: 5, Informative

    Interesting that they break down the future of hydropower not by its advantages

    I do not think it means what you think it means.

  3. What about Iceland? by dcw · · Score: 5, Interesting

    Not a single mention of Iceland in the article, I guess it is only an option if it is a 'Made In The USA' thing.

    --
    "All those, moments will be lost, in time, like tears, in rain. Time to die." Roy Batty
    1. Re:What about Iceland? by tonicblue · · Score: 5, Informative
      http://news.bbc.co.uk/1/hi/world/europe/2973885.st m
      http://www.hydro.com/en/press_room/news/archive/20 03_04/hydrogen_island_en.html
      http://business.guardian.co.uk/story/0,3604,943132 ,00.html

      They don't just use hydrogen.
      Some cities, such as Reykjavik, already use hydrogen to power buses. But Iceland gets some electricity and over 80% of its heating and hot water from geothermal energy sources, and can produce the hydrogen emission-free. Other countries need to find ways to produce the hydrogen sustainably.

      http://www.newscientist.com/channel/earth/energy-f uels/dn9984

      They are lucky they live where they do. It's a hot bed of free energy.
      --
      $ cat /home/tonic/sig
      cat: /home/tonic/sig: No such file or directory
  4. Hydrogen Not A Fuel? by mrdrivel · · Score: 5, Insightful
    From the article:
    But unlike oil and gas, hydrogen is not a fuel. It is a way of storing or transporting energy. You have to make it before you can use it -- generally by extracting hydrogen from fossil fuels, or by using electricity to split it from water.
    How is hydrogen not a fuel? I always thought fuel was a substance that when it goes through a chemical reaction releases energy. While many fuels are burned, the process of generating energy in a fuel cell is still a chemical reaction.

    Secondly, aren't there other fuels that have to be made before we can use them? Gasoline and diesel have to be refined -- it's not like we find them naturally in the ground.

    So hydrogen is just a way of "storing and transporting energy". I thought the use of fuels was a way to "store and transport energy".

  5. Crisis is in Transportation sector. by 140Mandak262Jamuna · · Score: 5, Informative
    We should recognize that there are two distinct energy sectors, and one is in crisis and the other one has some breathing space for a smooth landing.

    The fixed or stationary energy use, at homes, offices, and factories is not in as much of a crisis as the transportation sector. For electricity generation, there are alternatives like coal (yeah, it is dirty), or nuclear (yeah, most people fear it) or tar sands (yeah, it is expensive to recover) or wind (yeah, it has some problems), solar (yes, it needs high investment). There are problems, but USA is self suffiicient in them, and we wont be held hostage by foreign powers. There is breathing space to develop really good alternatives.

    On the other hand, in the transportation sector is in crisis already. So much of personal transportation depends on gasoline and freight depends on diesel and air transportation depends on kerosene. No serious alternatives are emerging and the time is running out on those sectors. Most predictions of peak oil is around now or 2010. Even the most optimistic estimates about the Hydrogen powered cars or biodiesel driven trucks talk about widespread adaptation around 2020.

    America is particularly vulnerable to this energy crisis. It is not as densely populated like Europe or Urban India and China. It is not easy to switch USA to use electricity driven public transportation. So much of the economy depends on the high home values of the sprawled cities and the humongous fleets of trucks delivering goods. So much of the infrastructure is built around the idea it is very cheap to transport goods over 100s of miles. And America is not self sufficient in this energy sector. This is a grave crisis.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  6. Climatology is full of scientific uncertainties by Morgaine · · Score: 5, Insightful

    It's not as clearcut as you make out. Try reading some actual scientific papers on the topic, instead of just listening to the media and politicians with an agenda. Scientists make a distinction between their actual scientific correlations and their preferred personal interpretation --- the latter is not Science.

    Climatology is full of uncertainties, and the general agreement among scientists goes only so far. The most important area of agreement is that CO2 operates as a greenhouse gas, but the extent of its contribution within the overall system is commonly misrepresented.

    CO2 is not the most important greenhouse gas, by a long chalk. Water vapour is the primary greenhouse gas on Earth, directly responsible for 95% of the global warming that keeps the planet from freezing solid to a dreadful -19 C or so. Global warming is essential.

    Climate modellers who want to highlight CO2 choose not to make that known to the man in the street, and the way they treat water vapour as a "feedback" in the GCM models instead of as a key mechanism of "forcing" tends to brush the importance of water vapour under the carpet. It's a somewhat questionable scientific approach because pure feedbacks should really be invariant linear amplifiers and not highly variant in their own right (as is water vapour), but what's worse is that this creates a hugely inaccurate public perception.

    The simple fact is that we live on an ice, water, and water-vapour covered globe moving in a somewhat complex way around a somewhat variant Sun, and that is the PRIMARY driver of climate, with water as its main agent of heat distribution and with just enough natural global warming to make it liveable, in between ice ages. CO2? Yes, it's relevant and it does have an effect, but it's not even close to being a primary player, and reducing our CO2 emissions will not have a significant effect in anybody's realistic scenario.

    And that's not under dispute by any scientist --- they know the maximum extent of possible direct warming per ppm of CO2, and they also know the maximim warming amplified through water vapour feedback in a cloudless atmosphere. But they're not even close to understanding well the magnitude of interactions in the upper atmosphere nor being able to model cloud formation well enough to determine what the real effect of 2X or 3X CO2 would be. To claim that anything in that area of climate forecasting is "established without doubt" is a total distortion of the truth.

    What's more, the natural variation in temperature across glaciation cycles totally swamps the changes calculated by any existing climate model, which just shows how we know very little in the larger context. We're right at the "natural" end of the current 18,000-year inter-glacial period, so expect a massive drop in temperature any century now. Can the GCMs predict that? Of course not.

    The uncertainties in this area are LARGE. They will be worked out. In the meantime, only non-scientists claim clearcut knowledge.

    --
    "The question of whether machines can think is no more interesting than [] whether submarines can swim" - Dijkstra