Alternative Energy Sources

[Mr. Lothario]

     I'm not so sure that fuel cells will improve all that much. After all, they are a 150 year-old technology. There is probably R&D that I'm not aware of that IS improving them, however. It wouldn't surprise me if I was totally wrong.

     Even if fuel cells do improve, they still require hydrogen, which requires electricity (or extremely high temperatures) to extract from water. That cost of creating fuel will take a big chunk out of the output of the fuel cells. I like fuel cells a lot, but I don't think that the technology is viable for power plants. Running individual factories, homes, etc., definitely. But as the central source of power for hundreds of thousands or millions of homes? I doubt it.

     I'll restate my views on solar: I think it's a dead-end. There just isn't enough power in solar energy (that is, the energy concentration is not high enough). In terms of solar, Earth takes it in the shorts from the inverse-square law. Even orbiting solar panels wouldn't produce very much electricity, and then you've added getting to orbit to the cost in money and materials of building the collectors. The only way that solar would be worth the effort in terms of energy produced is if we built collectors very close to the Sun, where the energy density is nearly the same as on the surface of the Sun. The technology to build and place collectors like that doesn't exist now, and it won't for quite some time. (But man, I'm looking forward to Dyson spheres.)

[kami]

Loth, I think those Dyson spheres and bubbles will stay in the SciFi genre for quite a while

There are many new ideas for good energy sources but none of them really beat the economy and output of nuclear energy, I don't think they'll become obsolete in a few lifetimes.

There are also fun ideas of using water as a fuel for cars, extracting the hydrogen from the water and making the car go with that, and then what's even greater is that the only pollution would still be just water! I don't know how far they've come in developing that but it sure sounds like a great idea if it works.

[Mr. Lothario]

     Those are fuel cells that you're talking about, Kami. As I mentioned, it's a very old technology (the patent is from roughly 150 years ago), and a very good one. It's purely a chemical reaction--no moving parts, and the only waste product is pure water. Fuel cells are almost certainly going to be THE technology of choice for small power needs, such as cars, laptop computers, and even homes and factories (industrial fuel cells have been in use for years to power factories). The technical barrier to wider acceptance of fuel cells is the fact that you need hydrogen to run them, and you have to store the hydrogen in compressed form to have a useful fuel reserve. Compressed hydrogen goes boom really nicely (a collision between hydrogen-powered cars would likely not be pretty). So until advances in compressed-hydrogen storage technology come along, fuel cells will only be useful in some applications.

[alaric]

loth,

    If I recall correctly the steam engine was invented over 2000 years ago. And the combustion engine was invtented around 150 years ago. When the device was invented is irrelevent, just because something's been around a while doesn't mean it's no good. They major reason gasoline combustion engine is so efficient is because it has benefitted from a century of billions upon billions of dollars of focused reasearch. If a similar of time and money was spent on fuel cells I think you would see the technology much more robust than it is today.

    Also, remember that hydrogen is one of the lightest elements around therefore it will float if it escapes from it's container. This GREATLY reduces the chance of explosion. The hindenburg was not hydrogen burning, it was the aluminum paint used to coat the hydrogen filled balloons. Gasoline vapor, on the other hand, sinks low to the ground and the liquid practically sticks to everything. Which would you rather have in a collision: a fuel which escapes harmlessly into the atmostphere quickly or one that lingers around at ground level just waiting for a spark?

    Though hydrogen fuel cell and hydrogen storage technology may be in it's infancy today, give it time. Already scientists have developed a container that you can fire an incendiary bullet through and the hydrogen still will not explode!

[kami]

No no Loth, it's a different idea where you have water to begin with and then separate the hydrogen from the water first, then you use the separated hydrogen. This would also alleviate the hydrogen storage problem, although alaric is right about hydrogen being a highly volatile gas, it's nonetheless explosive.. But he's right about the Hindenburg.

[Mr. Lothario]

just because something's been around a while doesn't mean it's no good.

As I mentioned, it's a very old technology (the patent is from roughly 150 years ago), and a very good one. [boldface added for emphasis]

   Also, remember that hydrogen is one of the lightest elements around therefore it will float if it escapes from it's container. This GREATLY reduces the chance of explosion.

     Are you thinking that the ignition is always going to be delayed until all the hydrogen has vented? A stray spark is never going to fly into the venting hydrogen? The fact that hydrogen rises has no bearing whatsoever on the chance of explosion. Hydrogen by itself is nonflammable, but once oxygen mixes with it, then it is explosive. As long as the hydrogen remains securely contained without leaks, an explosion is pretty much impossible. Firing an incendiary bullet through a containment tank is not particularly conclusive. Over several years during WWII, British fighter pilots shot thousands of rounds of incendiary ammunition at German zeppelins, and caused very few fires/explosions. Still, I'm glad to hear that they're making progress.

[|MP|Buccaneer]

Compressed hydrogen goes boom really nicely (a collision between hydrogen-powered cars would likely not be pretty). So until advances in compressed-hydrogen storage technology come along, fuel cells will only be useful in some applications.

They major reason gasoline combustion engine is so efficient is because it has benefitted from a century of billions upon billions of dollars of focused reasearch.

Though hydrogen fuel cell and hydrogen storage technology may be in it's infancy today, give it time. Already scientists have developed a container that you can fire an incendiary bullet through and the hydrogen still will not explode!

Ok, a couple of corrections and agreements all at once here.  

First, Internal Combustion Engines are not that efficient.  There was a curve we learned in physics about this (someone in engineering help me out here, BRAIN).  But basically, the best that an internal combustion engine could do was in the high 20's (like 27%).  More efficient were External Combustion Engines (in the 40's) and Electric motors.  Internal Combustion Engines were the ones chosen because the they were deemed safer then External and they had a good fuel source that could be marketed.  In the case of Internal Combustion Engines, most of the energy is given off as heat.

Second, and more to the point, Hydrogen does not explode!  It has a very small POP, not a big Boom.  For an example, the zepplin was already used, and, as everyone knows, it burned, it didn't blow up (but yes, the hydrogen did burn too).  And now I'll give you the math on why.

When you burn Hydrogen, you are combining two moles of Hydrogen with one mole of Oxygen to create one mole of water (H2O).  According to (and correct me if I use the wrong name) Boyle's laws of pressure, it's all about the moles baby.  So when you go from three moles, down to one mole, pressure is actually DECREASED.  Ah, but there is a little catch.  Pressure also goes up with temp.  And the combination of hydrogen and oxygen is pretty exothermic (gives off heat), so that would bring the pressure up.  

(on a side note, when you burn gasoline, you are taking one mole of octane and combining it with a couple moles of O2 and getting out something like 14 or 18 moles of exhaust from water to carbondioxide).

So, in a nutshell, if a tank of hydrogen gets a hole in it, and catches fire, you will have a gout of flame coming out of the hole.  Now lots of you should have seen this in high school chem class, but done with a tennis ball can and propane or methane.  Eventually, the flame gets smaller and smaller, and if oxygen is getting into the tank, there will come a time when they are at just the right ratio's to combine all at once.  In your chem class, the tennis ball can popped up off the desk.  With Hydrogen, it's much more like a firecracker going off.  That's assuming that oxygen is getting into the tank in the first place.  

If I had a typical BBQ size 25lbs gas tank, filled with Hydrogen, and you put two holes in it, one at the bottom and one at the top.  Light the hole at the top.  Eventually, the flame will die down and you'll hear a big POP.  But I wouldn't be afriad to stand next to it (except for my ears).

Ok, That's enough.

[Mr. Lothario]

     Now that you mention it, Kami, I do remember hearing about efforts in that direction. It would work quite nicely.

     I wasn't aware of that, Bucc. I had always heard that compressed hydrogen was explosive. Were those experiments you mentioned done with compressed hydrogen, or hydrogen at the ambient pressure?

     At any rate, all of this is beside the point (which is itself off-topic, but I'm conveniently ignoring that ). The point I was making was that fuel cells just aren't powerful enough to be a major source of electricity. In applications with small and/or localized power demands, they're excellent, but for large-scale power production, they just won't cut the mustard. That could change in the future, but I'm still much more in favor of nuclear power because it is a source of copious (understating the case), lightly-polluting energe, which is ready to use NOW--and don't forget its side benefits, for which nuclear is, imo, needed. Technology, with the exception of the biological sciences, has been stagnant for around three decades now. All new technology is merely quantitative improvements upon previously-existing technology. Nothing qualitatively new has been invented in decades. Nuclear power's side effects could be the key to getting out of our rut and continuing our push forwards.

[The Ghost of Bondo]

    At any rate, all of this is beside the point (which is itself off-topic, but I'm conveniently ignoring that ).

I think our discussion of alternative energy sources (meaning non-fossil fuel) turned out to be much more interesting than any discussion of N. Korea and Iran would have been.

[kami]

Indeed Bondo..

What I like about the water thing is that you'd be able to have the old gasoline stations with the pumps, but with water instead, so you'd be able to put out fires with a gas hose

[The Ghost of Bondo]

I like the idea of just washing your car and then deciding to fill up while you have the hose out

Although I suppose you would want distilled water for the car so you didn't get a build up of the minerals in drinking water and thus you would need to get it from a station.

One comment on water as a fuel though.  That becomes a tricky supply issue as well.  Here in the west we have immense water supply issues.  If suddenly it is needed in huge quantities to run cars that only strains it more.  Mind you since it comes out of the car as water as well it goes back into the water cycle but it would still likely cause problems if the water was taken locally.  Water is basically like energy and mass...it can neither be destroyed or created...the amount of water on the Earth is the same as it has always been and always will be provided we have an atmosphere.  But the location of water does change resulting in desertification.

Anyways, I still hold out hope for the technology, they just need to think about these issues.  Water rights is a huge issue throughout the world.

[Mr. Lothario]

     Nuclear power's heat could be used as a "free" (the heat's already being produced to power the nuke plant's turbines) way to desalinate large quantities of seawater. That would make a large difference in the amount and locality of useable water in the world.

[kami]

If water was to replace gasoline then I think you would find it very economic to start desalinate sea water in large quantities so I wouldn't worry about that.

[alaric]

The really cool thing about getting your hydrogen gas directly from water is that you don't even need to desalinate before doing it. In fact, it works much better when it's salty.

When my junior high science teacher was using simple direct current to separate water into hydrogen and oxygen, we actually had to add salt to make it work.

Granted you wouldn't want to use filthy water but the point is just about any water source will work right off the bat.

Another interesting thing is the recent discovery of an algae that gives off hydrogen as a byproduct of it's normal life-cycle! This means that with development of the algae we could potentially have a 100% envirofriendly source of limitless power.

[kami]

Damn, that's pretty cool alaric, new info to me.

[|MP|Buccaneer]

Hydrogen, being by far the most common element in the universe, is found in more then water, so that's not the only way to get it.

And, like I said earlier, the fuel cells they are working on for the home can also work off the natural gas that most homes already have coming in.

[kami]

But you must agree that water is the best and easiest molecule to split up in search for it.

[Mr. Lothario]

     Heh. Kami, I'm gonna rag on your last post there. My Logic teacher would have ripped you a new one for saying "you must agree". That's a logical fallacy--if I recall correctly, it's begging the question (but the Latin name slips my mind). Begging the question is a fallacy in which the argument assumes that the conclusion is already proven. Words like "clearly" (clearly, Lincoln was the best president), "surely" (surely you'll see), and "obviously" (obviously, my point is true) are all no-nos in logical arguments, just because they're assuming that your argument is true and correct, when you haven't proved that yet.

     A friendly heads-up from Logic Man. Heh.

[|MP|Buccaneer]

And, to prove a point Kami, NO.  I don't agree.

Especially since I've said that it can take the hydrogen right from Methane and Propane without needing a middle step.

Added to that the fact that most homes in America have one of those gasses already being pumped in.

So, I think getting it from water is a great thing, but not the best or easiest.  Not yet.

[kami]

What I meant is that it is the best molecule in respects to how much of it we have here on earth, endless amounts of it... Easiest because it's such a simple molecule, that of course does not always have to be true.