git ssb

title: > Hydroelectric date: 2007-11-10 12:51 status: published

tags: hydrogen power, power generation, the environment

<p><b class="lede">Given that hydrogen fuel cells can be used to run cars, why not use them to run power stations?</b>
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<p>Though I'm not overly familiar with the physics of it, hydrogen fuel cells operate by exploiting the energy released when hydrogen (H₂) and oxygen (O₂) recombine (in a 2:1 ratio) to form water (H₂O). </p>
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<p>I'm assuming that this process is energetically beneficial; that is, you produce more energy in a fuel cell than it takes to produce the fuel. </p>
<p>I'm also assuming that the only thing stopping widespread deployment of hydrogen fuel cells in cars (which I think is the venue most often discussed for fuel cells' use) is the logistical problem of refueling such cars in everyday use: containment suits are needed when pumping the very-cold liquid hydrogen—or is it oxygen? or both? Anyway, a very-cold liquid—into the cars. And, while petrol stations are conveniently ubiquitous (for the most part, anyway), none of them stock hydrogen (and/or oxygen—whatever we decided was the stuff being pumped); <em>this</em> is largely because there are no hydrogen fuel-cell–powered cars in everyday use. It's the proverbial chicken-and-egg situation (let's pretend, for rhetorical purposes, that that one <em>wasn't</em> resolved (it was the egg <i>(no, I'm serious)</i>)). </p>
<p>These problems don't, however, stop hydrogen fuel cells (or the same technology, perhaps not in an actual <em>cell</em>) being deployed in <em>centralised</em> systems—like power stations. The chicken-and-egg problem is resolved because popular demand isn't needed to make it commercially viable to supply the technology, the infrastructure or the fuel itself. </p>
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<p>It's definitely possible (at least I'd be very, very, <em>very</em> surprised and bemused if it weren't) to run a power station using hydrogen fuel cell technology: most (perhaps all) modern power stations operate by heating water. Coal-fired and nuclear fission-powered power stations both use the energy released from their respective reactions to heat water, which becomes steam; as the steam rises it turns a turbine; this turns a magnet in a solenoid (a tube-shaped coil of wire), which induces an electric current in the solenoid. </p>
<p>Hydrogen fuel cell–powered cars have wheels that turn. Attach a magnet to one, put it inside a solenoid <i lang="fr">et voilà</i>. </p>
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<p>The benefits of using hydrogen power, rather than fossil fuels or nuclear fission, to produce electricity would be plenty: removing the “kettle” stage from a power station would be a novelty; it would probably increase efficiency <var>lots</var>-fold, and it certainly (defined like “definitely” above) wouldn't <em>decrease</em> efficiency. </p>
<p>The environmental benefits are pretty substantial too: hydrogen and oxygen exist in abundance in water, and the only by-product from the fuel cell reaction is hot water. As long as this hot water isn't pumped into rivers at such a rate that a river's temperature rises significantly, which would piss a lot of aquatic animals off rather a lot, to say the least, the environmental concerns are nil—you can safely pump water into the atmosphere (almost) with abandon. </p>
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<p>There must be an obvious stumbling block that I've overlooked; otherwise, why aren't <em>all</em> the cool More-Economically-Developed Countries doing it? (And I doubt it's collusion with the fossil fuel industry—there are lots of rich countries without a vested interest there.) </p>