Intoxicated by hydrogen

Posted by jerry as alternative fuels, technology

Here we go again: http://www.businessweek.com/magazine/content/06_48/b4011432.htm?campaign_ic=bier_innvg

First hydrogen fuel cell motorcycle.  Yay.  We can crank these things out for the 3rd world masses and urban dwellers and our pollution problems are solved.  One of the comments on that page sums up the great misconception about hydrogen fuel cells well: you just put water in, the fuel cell splits out the hrdrogen, then converts the hydrogen into water which produces electricity.  Sadly, that’s not how the world works, Johnny.  If it did, I’d quit my job and I’d cranking out electricity from the Chattahoochie River like nobody’s business. 

You Cannot Get Something For Nothing

Fuels cells are simply a method of converting a fuel directly into usable energy, without most of the waste heat losses involved in burning it to turn a turbine, push a piston or boil water.  You must supply it with hydrogen to use.  That hydrogen has to come from somewhere.  The only real method we have to produce hydrogen on any scale is through electrolysis of water.  That takes electricity.  More electricity than is obtained through the fuel cell. 

Hydrogen is NOT an energy source

Unlike gasoline, hydrogen is NOT a source of energy.  It is a storage media.  It is the equivalent of a battery.  Electricity has to go into it, in order for anything to come out of it.  The only exception to this is if we somehow found a deposit of “pure” hydrogen or we were able to magically pull the hydrogen out of water without using more energy than can be obtained from the extracted hydrogen.  So far, neither seems likely.

Hydrogen Economy

You may have heard of the “hydrogen economy” before.  Basically, that’s the production and distribution of hydrogen on a scale equivalent to diesel or gasoline.  Major “refineries” which would extract hydrogen from water, pipelines and tanker trucks to move the presumably liquid or compressed hydrogen around, and fuel stations to deliver the hydrogen. 

All Is Not Lost

While hydrogen is not the panacea that many people understand it to be, there are some big advantages.  The primary advantage is that it uses electricity to create.  That means that we can use conventional nuclear power, solar power, geothermal power, wind power, wave/tidal power, or the more traditional coal/natural gas power.  Large scale production will yield efficiency improvements in extracting hydrogen from water.  The second great benefit is that it’s really easy to create.  Conceivably, a small “reactor” could be bought for home use that would plug into your house electrical system, connect to your garden hose to feed it water, and output hydrogen directly into your “gas tank”.  Gas stations are no longer a necessity and will likely have a hard time competing with home produced hydrogen, unless the mass produced variety can be produced much more efficiently.

Problems Ahead

Hydrogen has some steep drawbacks.  The attribute that makes is a good energy storage media also makes is very dangerous.  Hydrogen is very energetic.  Fires or explosions that result from hydrogen tanks on vehicles will be very deadly.  Hydrogen is also very hard to contain.  It’s small molecular size allows it to seep through even solid metal containers, however slowly.  Refueling will also be much more dangerous than it is with gasoline.