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Hydrogen Won't Save Our Economy
anaesthetica writes "Physorg.com is featuring a story asserting that hydrogen is economically infeasible as a replacement for our current energy sources. The premise is that isolating and converting hydrogen into a usable energy source takes up a great deal of energy to begin with, and that subsequently converting that hydrogen fuel into usable energy results in an overall efficiency of only about 25%. Apparently, the increasing scarcity of water is going to make hydrogen too costly and just as politicized as oil." From the article: "[Fuel cell expert Ulf Bossel's] overall energy analysis of a hydrogen economy demonstrates that high energy losses inevitably resulting from the laws of physics mean that a hydrogen economy will never make sense. The advantages of hydrogen praised by journalists (non-toxic, burns to water, abundance of hydrogen in the Universe, etc.) are misleading, because the production of hydrogen depends on the availability of energy and water, both of which are increasingly rare and may become political issues, as much as oil and natural gas are today."
I read somewhere that some consider hydrogen to be sort of a liquid battery. It costs energy to make it so it's really just a transference mechanism between the source of the energy and your car. The benefit is this, though: That source does not have to be oil. It can be anything. Wind, nuclear, squirrels in hamster wheels, anything. It will not solve our long-term energy problems, but it could help relieve our dependence on foreign oil.
Sugar, like most other forms of easily accessible energy, is dangerous stuff. It only seems harmless since complex mechanisms have evolved to deal with it. Sugar is hydrophilic and will kill microbes that come in contact with it by dehydrating them. It will also destroy cells that contain too much of by osmosis. Your body needs to keep the level of sugar in the bloodstream within very tight limits, or bad things will happen.
(Yeah, I know. Completely offtopic.)
You didn't read the article. Hydrogen is just a 25% efficient battery. We already have much better batteries.
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Considering that 3/4 of the planet is covered with oceans, at some points kilometers deep, I fail to see a "water shortage". There may be a shortage on fresh water, yes, but salt water elctrolyzes just as well (even better, since it contains ions). To boot, you end up with sodium, chloride and some other chemical elements that can be sold as by-product.
The real problem with hydrogen is that it's an inefficient way to store energy. Plus, storage is difficult since it's a very tiny atom (one proton only...) so it tends to seep out of every container; it's highly flammable, and to store it effectively you need either very high pressure, or very cold temperatures (20K). Gasoline really isn't that bad for a fuel...
No, the real boon would be to either store electricity very efficiently, or somehow convert the CO2 in the atmosphere directly into fuel again, using some form of renewable energy like the sun.
"Fix it? It has been disintegrated, by definition it cannot be fixed!" - Gru in Despicable Me.
This is the only thing hydrogen can do. We store energy by producing hydrogen, and then release it when we want to use it. It's never been proposed that hydrogen will magically solve the energy problem, just that it might be a good way to store/transport what energy we do produce.
The study's claim is that this is not a good idea, since the two step chemical process is simply too inefficient.
Has anybody seen that documentary movie "Who Killed the Electric Car?" In it, they look into hydrogen vehicles and the auto industry's support for it, but get a technician involved to admit that these machines are nowhere near being available to the public. This idea, along with Bush's much vaunted "hydrogen economy", is nothing more than a white elephant -- a strategy for getting the public think that the industry is doing its best, while in actual fact hydrogen powered vehicles are a dead end. They pay lip service to the idea by investing few million a year into their hydrogen research projects, while in the mean time moving along with business as usual.
As the movie points out, electric cars are the real answer: they're simple, cheap, fast, efficient, convenient and low maintenance, so there's absolutely no need for hydrogen to enter the equation. Hydrogen just makes these cars more complicated and less efficient. The only thing holding back the electric car is the will of the industry. For instance, Chevron holds the patents for one of the most promising battery technologies, but they specifically forbid the current manufacturer to sell them for use in private vehicles (only public transport).
I suppose you could argue that the auto manufacturers the oil companies are only acting in the best interests of their stock holders, and that's probably true, but at this rate they might as well be evil.
and yet, it still says idiotic things...
/drinking/ the hydrogen... I don't see that as being a big issue.
As far as the hydrogen goes - it's a good point, it's not a fuel source, it's a transport mechanism, since we don't have a lot of easily collectable hydrogen around - we have to obtain it by expending energy. Hydrogen should be thought more in the lines of electricity than of gas, just that it has different uses.
As for "water running out"? WTF? Clean water may be diminishing, but the amount of water on the earth probably hasn't fluctuated by even 1% over the past billion years. Seing as how we aren't
And anyway, take the hydrogen out of unclean water... Well, when that hydrogen mixes with oxygen, I gurantee you the water will be clean.
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I've been charging batteries with efficiency of around 85%. High-efficient switched mode chargers can reach even higher numbers.
And if the target load is much smaller than the internal battery impedance, you get near 100% efficiency using the stored energy, at least at battery's terminals.
Battery is not a waveguide. You don't match its impedance to the load (and lose half of the energy if doing that)!
Alcohols also need to be made, although there is at least a slight energy gain in the process (stored solar energy in the plants you ferment). Converting a perfectly viable fuel like Alcohol into hydrogen is pointless: You lose energy in the conversion and you still release the carbon into the atmosphere.
You are correct in saying that hydrogen is rarely produced by electrolysis due to energy consumption. Do you know how it's really made? Reforming natural gas - a fossil fuel! Congratulations, you've managed to shift our dependence on fossil fuels from crude oil to natural gas (which is even more scarce) while reducing the overall energy yield from the raw fuel and still not reducing carbon emissions.
Metal hydride storage uses some pretty expensive, toxic and dangerous materials and still does not achieve the hydrogen storage density of more common and safer-to-handle fuels such as gasoline and diesel fuel.
It's a trifecta of failure.
=Smidge=
Actually, I was watching a program last night on the History Channel -- not exactly peer reviewed scientific literature, I realize, but IMO on par with TFA -- which was talking about the viability of wind power in the United States as a renewable energy source.
They pointed out that although wind does take up space, it's not as if the space it "takes up" can't be used for other things. They had some interesting shots of farmland out in the midwest where there were wind generators standing in the middle of the fields. The actual footprint of the generator on the ground is pretty small. Though I suppose its shadow might reduce crop yields in the surrounding acres slightly, one assumes the electricity generated must be enough to make up for this cost to the farmer. Probably the biggest drawback of having them all over your field is that it becomes harder to spray your crops using aircraft, but that doesn't seem like a total deal-breaker.
There's a whole lot of farmland out in the middle part of the country which also has pretty steady winds, and is already being used for what basically amounts to an "industrial" purpose (large scale high-yield farming). If you can show the owners of that land that they can increase their financial yield per acre by adding wind turbines to their fields -- basically giving them another cash crop besides food -- you probably wouldn't have as much of the NIMBYism that plagues wind projects in more residential or coastal areas. (Although I think eventually, those people are just going to have to suck it up and learn to enjoy looking at turbines; 100 years ago, people probably bitched about having a lighthouse mucking up their view, but now they're considered a beautiful addition to the landscape. Surely generators could be the same way in time.)
Although I think in the short term, nuclear (fission, obviously) plants are probably our best bet towards cutting carbon emissions and reducing our dependency on foreign energy sources, wind turbines seem close to being practical. Most of the objections to them seem to be aesthetic, and when it comes down to having your lights go out, or having some sort of power plant in your backyard, wind turbines seem a whole lot nicer than a coal-burner or nuclear facility (or being flooded out for a hydro project).
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Clean potable water is surprisingly hard to access in quantities outside the developed world (and becoming far more scarce daily). Aquifers in the US are sinking (some with alarming speed). You generally can't just stick probes in the ocean and create industrial levels of hydrogen.
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But, funnily enough, nobody wants to buy an electric car, despite the fact that they'd probably be cheaper to run. Why? Because the range and performance is unacceptable to most people. And it's the same with a fuel cell vehicle compared with a battery-powered electric car. Sure, the hydrogen might be more expensive than the equivalent power straight from the grid. But the car's range and performance will be much better than the battery car.
Furthermore, he makes the strange assumption that the hydrogen will be coming from room-temperature electrolysis. That's highly unlikely. It's much more likely that hydrogen will be produced using chemical processes on fossil fuels (using geosequestration to dispose of the resulting CO2), by using a nonchemical source of heat (such as a nuclear reactor or solar furnace) in high temperature electrolysis, or through all manner of nifty renewable hydrogen sources that don't involve producing electricity and then doing electrolysis.
Any sufficiently advanced technology is indistinguishable from a rigged demo
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I seem to remember from my sixth-grade science project that pure water doesn't split using electrolysis very well because it's too good an insulator. The research I did (in the 1980's) suggested that out of household chemicals easily available to me, I could add either vinegar or table salt to get the process to operate faster. After trying some different levels of each, I chose to add a little of both to the water in my final demonstration.
If you're concerned about putting a little metal into the oceans, perhaps floating oil rigs, submarines, torpedoes, and deep mineral mine runoff should be targets before anodes and cathodes on electrolysis equipment. The oil and agricultural chemicals we're putting in the water now are pretty bad, too. If your alternative fuel is alcohol, then count on more agricultural chemicals allegedly causing infertility, learning disorders, and other health problems downstream.
If we make hydrogen from seawater, then burn the hydrogen, then we're making clean, desalinated water. That can be used for drinking water, irrigation, or whatever. If it's released into the atmosphere, it'll become clouds and rain -- at a faster rate than through natural evaporation. As for how we use the hydrogen once we have it in sufficient quantities, sustainable hydrogen fusion in traditional local and regional centralized power plants may be a future option.
Nuclear fusion has already been used for thousands of years to desalinate seawater for irrigation -- it's called the water cycle.
Batteries are neither cheap or clean: they contain lots of toxic chemicals, have a limited life time, and due to Ohm law, can only give back only half of the energy that was put into them.
You're confusing two issues: Maximum POWER versus maximum ENERGY when pulling power from a voltage source through a fixed resistance.
If you want the maximum amount of POWER (rate of energy delivery) and the resistance is fixed, you get it when half the power is delivered to your load and half wasted in the series resistance. Efficiency is 50%. (This assumes ideal fixed voltage source and resistance - a bad assumption when loading a battery with a near-short.)
If you want the maximum ENERGY from your battery you pull much more slowly. Efficiency would approach 100% as discharge time approaches "forever" (though a real battery has leakage and a real load usually requires more than a trickle, so you waste a few percent to do things at practical rates and power levels).
Same is true for the power grid. The system of generators, transmission lines, transformers, and miscelaney has overall efficiency far above 50%. You don't put so little copper in your wires that you're loading it at the peak of the power curve and half is wasted heating (and melting!) the system. You put in a BUNCH MORE and never draw power anywhere near the maximum you could draw.
Example: My neighborhood has something like 50 houses served by a "bank" of three paralleled "pole pig" transformers on one edge of a primary delta - call it 12 KV. Rule of thumb for homes is they draw about a KW each, so call it 50 KW and a tad over 4 amps in the primary wiring. It's fed with bare #10 copper, which would easily carry 30A embedded in insulation in a wall without noticable warming.
A couple years ago a goose flew into the primary wiring. The current melted the #20 in two places in less than a second and draped the primary wires all over the street. That means the goose was getting FAR over 30A. Let's be conservative and say it was 300A and dragged the voltage across the goose (and the arc to it) down to zero, which would put the half-power point at 150A and 4 KV - 600 KW. Normal load current would be about 2.7% of that, and resistive losses in the grid (as a percentage of power delivered) would be about 1.3%.
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It's true that we need water to produce Hydrogen, and that it's inefficient, and that using salty sea water may be even more inefficient, but if we have hundreds of thousands of cars spewing out steam instead of CO/CO2, wouldn't that help SOLVE the water scarcity problem? Isn't all that steam going to come down as rain. And since we've transorted it from the coast inland, isn't it more likely to come down over land? Someone will probably chime in with a scathing reply about it not being enought water to be to make a difference, but isn't that what we though about oil-based combustion products.