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."
Agreed, of course, but there is something fishy about the article.
FRAUD??? It's true that making hydrogen is not an efficient way to store energy
for use later. However, this quote is partly nonsense: "... the production
of hydrogen depends on the availability of energy and water, both of which are
increasingly rare..." Water is not rare, and is could never be a problem
with the production of hydrogen. I doubt that a reputable publication would
print nonsense like that.
Not only is something very wrong with the article, but something is
not right with the article's source, Physorg.org. Here are some Google ads at
the site that seem full of fraud: "Sponsored Links (Ads by Google)
-- The Next Oil Boom - See who's pumping cash by making oil for $13.21. And
selling for $59. And another: Free Top Energy Profits - 5 Triple-Digit Investment Gains
in Today's Alternative Energy Boom." An honest organization would never
allow advertising like that, I think.
This article on the same web site seems like the beginning of fraud to
me: A
Printer that Delivers 1,000 Pages a Minute? [physorg.com]. There is NO printer. There is
only a poorly edited article in the online (not peer-reviewed,
apparently) edition of Applied Physics Letters. The idea is called JeTrix (Jet
Tricks) by the supposed developers. The idea is that a printhead that covers
the whole sheet of paper can print faster than one that is small.
Recently, Slashdot has been carrying discussions of "scientific
breakthroughs" that are in actuality attempts to get money from investors. The
Slashdot articles are, in reality, press releases for extremely poor
investment "opportunities". Is a Slashdot editor taking money to run these?
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.
Yes, but I can still extract Hydrogen from mud, so what's your point? Why are you commenting on the lack of clean water for hydrating animals as if its relates to energy economics? Its a completely different problem altogether. Once the energy problem is fixed, then I think getting clean water everywhere will be a lot easier by truck than by foot, don't you?
So by your logic its too hard to distribute clean water and too hard to extract "industrtial levels" of hydrogen from probes in the middle of the ocean, so what, just die when the oil runs out? Gee thanks, brilliant. Got any other ideas?
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.
Not so much potable as not seawater. To generate hydrogen in the amounts needed to power transportation you are going to have some serious issues with chlorine and insoluable percipitates [harvard.edu].
Here are some Google ads at the site that seem full of fraud: "Sponsored Links (Ads by Google) -- The Next Oil Boom... Free Top Energy Profits..." An honest organization would never allow advertising like that, I think.
If they are using Google to sell ads they don't control the ads. Their site relates to energy issues, so ads for energy-related scams will match in the placement algorithms.
Hydrogen can be produced from alcohols by cracking and water-gas shift reactions. Hydrogen is rarely produced by electrolysis because of its power demands. Hydrogen can be stored as a metal hydride at relatively low pressure then released at atmospheric pressure.
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 not really a trifecta of failure. Both electric and hydrogen power have a big advantage: a staged move away from fossil fuels. Yes, right now they both require us to get our power from dinosaurs. However, in some hypothetical future, we all have solar panels floating out in the ocean making us hydrogen from seawater, or we all have solar cells on our houses charging our batteries, or we've moved to nuclear power. In all those cases, we can semi-gracefully make a switch from making our hydrogen from natural gas to making it from clean electricity. However, if we stick with gasoline, we're kinda screwed when it runs out.
Alcohol is one answer, but it's not exactly perfect either.
The carbon you are releasing is carbon that has already been removed from the atmosphere. It's called 'Carbon-nuetral' for a reason.
Of course this is correct. I'm a huge supporter of biofuels as a renewable energy source (obviously) and I think carbon neutrality is a major selling point. However it's still wrong to say that Hydrogen is a carbon-free energy system when it's refined from a hydrocarbon source - especially a fossil fuel.
Reducing energy yield, yes. Reducing efficiency, no. Hydrogen/electric cars are significantly more efficient than gas ICE cars. So while you have less energy to use when you put the fuel in the vehicle, you use less energy to get the same output from the vehicle using hydrogen.
While burning hydrogen may be slightly more efficient, the energy density is significantly lower resulting in more fuel being burned for the same output. In the end, pound-for-pound, Hydrogen seems to offer no significant advantage.
When you consider the requirements to manufacture and store the Hydrogen, I challenge that the efficiency from energy source to point of use is actually very poor.
People love to shoot down alternative fuels because they aren't able to replace ALL of the vehicles on the road.
Hydrogen is not an alternative fuel. That's the problem. So far, whatever source of energy you're using to make the hydrogen - electricity, natural gas, etc. - can be better used directly instead of pissing away half of it using hydrogen as an intermediate.
I completely agree that there is no single solution, but I do not agree that pure Hydrogen as a primary link in the energy flow is ever going to work. Biofuels are a much safer bet, being renewable, carbon-neutral, 100% compatible with existing infrastructure and closer to the energy source. =Smidge=
Hydrogen is not an alternative fuel. That's the problem. So far, whatever source of energy you're using to make the hydrogen - electricity, natural gas, etc. - can be better used directly instead of pissing away half of it using hydrogen as an intermediate.
You seem to be missing the two fundamental points of a hydrogen economy.
1) A hydrogen economy is not bound to a specific liquid fuel. Ultimately, a hydrogen economy is an electric one. Not many are predicting "peak electricity" any time soon. 2) A hydrogen economy is very efficient. That is, to say, electric vehicles (which is what hydrogen-fuelled vehicles are) can easily recover energy, electric engines are very efficient, fuel cells are up to ~70% efficient, electrolysis of water is ~90% efficient, etc.
Of course, in the mean time, until thermolysis of water (say, from nuclear power) or farmed hydrogen (say, from genetically engineered bacteria) is available, producing the hydrogen is a somewhat wasteful stage that's reliant on natural gas. Only "somewhat", however. Natural gas reforming produces H2 and CO. CO can be burned for heat. As a result, apart from incomplete combustion, all of the energy of the natural gas either goes to H2 or heat. Heat can be used to do work. Indirectly (subject to carnot cycle losses), it can generate power. More usefully, however, is it can heat processes that need heat inputs -- industry or even home water/house heating. In such a case, you only "lose" a tiny amount of the natural gas's energy.
Of course, even if you consider all of non-H2 energy wasted, as this article does, you're left with the following possibilities:
1) 30% efficiency on your typical ICE gasoline engine.
OR
2) 25% efficiency on your typical natural-gas derrived hydrogen engine, which is automatically a "hybrid" and can thus save power by regenerative braking. And, since it uses natural gas for the hydrogen, which is currently more available than oil, it reduces stress on the oil market. If natural gas prices rise too much, pressure on natural gas markets can be allieviated by switching from natural gas power plants to coal/nuclear (as happened with the oil-driven power plants in the 70s).
Is the second option really that bad -- present day? Especially with some of the new high-density hydrogen storage systems hitting the market? I think not.
As an aside, I ran into an interesting proposal for hydrogen storage that costs 1/3 as much as conventional storage tanks: commercial-scale wind turbines. They're huge hollow shafts. The extra cost to make the turbine able to hold hydrogen is something like 85k$, and an equivalent-sized tank costs something like 250k$.
sun and wind power are, IMHO, the alternative to oil and coal
Wind won't work outside of a very few areas that have the kinds of sustained winds to make it workable. In general, it just takes up too much physical space for the energy it generates.
Solar is potential workable, but not with single-crystal silicon wafers. Those actually require quite a bit of energy to create, and take (I believe) over a year to "pay back" that energy. Recent research into nanocrystalline materials has more potential there
Wind won't work outside of a very few areas that have the kinds of sustained winds to make it workable.
Why impose additional constraints on new solutions to old problems? Hydroelectric power also won't work outside a very few areas where there is enough water and elevation difference, coal thermoelectric plants are impractical outside areas where you can strip mine coal, nuclear fission power plant is not feasible where you don't have uranium available (or water for cooling for that matter, or where it is IMBY). All this "downsides" didn't stop us from building and using each one of them. Why should we now suddenly make such an exception for wind power plants only?
Ever heard of Niagara Falls hydroelectric plant and Nikola Tesla? Back then, the guy demonstrated that energy can be harvested in remote locations, then conducted to areas of deployment.
Unrelated to that, but similar in paradigmatic sense, note that petroleum is used throughout the world, even though it is obtained only from handful of regions of the planet.
So, the only thing that actually matters for whichever energy production is: is it doable anywhere?
Wind won't work outside of a very few areas that have the kinds of sustained winds to make it workable. In general, it just takes up too much physical space for the energy it generates.
Solar is potential workable, but not with single-crystal silicon wafers. Those actually require quite a bit of energy to create, and take (I believe) over a year to "pay back" that energy. Recent research into nanocrystalline materials has more potential there, as they require less energy to create.
Actually both are space hogs, especially if you are talking about actual wind or solar 'powerplants'. However each has the potential to produce say... very rough guess here... up to 10% of the energy needs. In Europe wind is extensively used, farmers often set up wind generators on their fields and sell the electricity they don't need to the energy companies for extra income. If you drive through Denmark, Holland, or N-Germany you will see wind generators by the dozen in the wheat fields you drive through. I don't think either wind nor solar will replace coal and oil for all sorts of reasons of which the physical space they take up is only one reason, they will remain important supplementary energy sources. Large solar power plants are not all that common here in Europe but people have begun to combine improved insulation of their houses/apartments with measures like mounting solar cells on the roof to reduce the amount of energy they have to draw off the electric network for heating/cooling or lighting in their houses. Basically I think we can get far by encouraging the use of wind and solar and combining those with measures aimed at increasing the efficient use of energy but even all those measures together will never enable us to replace oil and coal. Unless somebody finds miraculous new energy source and invents room temperature super-conductors in the near future, conventional Nuclear power may prove the only viable way to phase out fossil fuel use in power plants. Nuclear leaves nasty waste products that will be hard to deal with but at least it doesn't cause a rise in sea levels and climate change. The choice we have at the moment is:
Nuclear power plants, which if they fail render the portion of the planet where they are located and any territory down wind them un-inhabitable for several thousand years.
Coal and oil plants who have the potential to render even larger portions of the planet un-inhabitable than Nuclear accidents will because of sea-level rise and the rest of it ill-inhabitable because of climate change.
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).
"but even this will be useless if we don't put serious brain power into improving the eficiency of our gadgets/cars/homes/etc."
How about putting some serious brainpower to changing cultural values? How much fucking space, heat, energy, electricity is wasted every year because each family/individual has a house/apartments much bigger then they need yet no people populate the extra empty rooms during the year, etc? Society in their desire for privacy / personal space creates a huge tonne of fucking waste simply through their animal prejudices and "preferences" (read programmed evolutionary emotional responses), we could save a TONNE of money and resources of we did something to develop superior cultural values. How much money would be saved on social programs if governments gave tax breaks to people that took the disabled, homeless, etc into the free space in their homes rent free, etc? How much good could come if people simply weren't dogs infected with the backward behavioural baggage of evolution.
Maybe we should all live in a hive, possibly with a monarch as a king?
How about we sleep only in standing closets, or pull out rolling beds?
Maybe we could all live life in a gigantic bunk house with public showers?
Why not get rid of cars and bus's and airplanes and boats entirely? Heck, weve got internet now, everyone can telecommute right?
in fact, why not just jack everyone into a grid... lets call it... a matrix. And allow them to interact in a virtual world that resembles our own? Maybe a second life... nah.. i like matrix.
And maybe we could tweak that virtual world to remain always near perfect, but not quite perfect.
Humanity like most life is designed to consume resources as much as it can, the gambit is wether or not we can find a way to maintain our growth through such consumption. Compression and self-lessness are only positive if they are natural or necesary. Compelling our current society to live in pods would be foolish, detremental, and likely a catastrophe. While condensed living is a requirment in most major population centers, youd be surprised at just how comfy people who live in rural or semi-rural europe/asia/America/Africa are in terms of space.
This planet is BIG... REALLY BIG... on a magnitude thats hard to describe. You could suggest we all go underground too, with equally disasterous results. But te key to our "evolution" is to be the first bit of life to succesfully get off this rock in a self sustainable manner.
Which is exactly why population density not being a preffered condition is a good thing, it forces us to open up new frontiers and search for more space... you know... doing that "life" thing.
We keep growing like this and we might die.... We stop growing, and we will die for sure.
It all depends on who you regard as "rogue nations running around doing anything they want". From where I'm sat, that description looks more like Bush's USA than Iran.
hydrogen should be used just as storage/transport of energy.
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.
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.
And the author of this study makes a trivially false claim in this regard: "We have to solve an energy problem not an energy carrier problem."
No, we have an energy carrier problem. We have all kinds of sources of energy. Wind, wave and most of all solar are more than abundant enough to supply the world's energy needs if we could just package and transport that energy with reasonably high volumetric and gravimetric density. If those sources are not enough then nuclear, for all its problems, is perfectly capable of filling the gap. But all of these sources most easily produce electricity, which has limited utility as a carrier of energy, particularly for transportation. The energy density of batteries, to say nothing of the conversion efficiency at anything like full discharge, is far worse than hydrogen.
Beyond that, the author makes a strong claim about the economic feasibility of the hydrogen economy. We all know what an exact science economics is, and how economists routinely make accurate and empirically validated predictions of the future of technological trends. So the author is arguing about the wrong problem and reaching an implausibly strong conclusion.
the availability of energy and water, both of which are increasingly rare
Eh? What about that huge nuclear furnace in the sky? And the ones we'll be building on Earth? What about two thirds of the planet's surface? That's not runny cheese you know!
It doesn't really matter if water is scarce or not, since contrary to gas/oil it can be re-used; it's only an energy carrier. Also, 3/4ths of our planet is covered in the stuff.
It seems unlikely that some magic bullet will come and solve all our problems. The largest part of any solution has got to be a dramatic downward trend in energy consumption regardless of the source.
There is no such thing as cheap and clean energy, all we will ever have will be energy that is relatively cheap and clean corresponding to our technology level. -Oil looks cheap because we are using in a few centuries the production of millions of years. -Wind or solar energy comes free, but to use them, you need devides that need to be built, maintained and trashed, and due to their power source, they can have significant downtimes. Solar pannels also contains a lot of dangerous materials (As, Ge, Ga...) and their production causes some nasty pollution. -Nuclear power is probably the best we can have today for fixed power generation: we have largely enough uranium to wait for the fusion reactors and the generated pollution doesn't go into the atmosphere and therefore can be processed, but there will always be a risk with that. And of course, for the portable energy -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.
-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.
I'm afraid this is incorrect.
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)!
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%.
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.
You must be new here, Mr UID 2679. If the "editors" don't bother to read articles before submitting them, I don't see why we should bother reading them before commenting.
If we use solar, wind and tidal energy to charge the hydrogen batteries, what difference does energy efficiency make, so long as current and future energy needs can be met?
Well, you take your energy as hydrogen, I'll take it as electricity at 1/4 of the price...
And it gets worse. Assume we're not going to use 100% *cough* renewable electricity. Assume your energy comes from a local coal power station. They're about 35% efficient, so your 25% efficient battery actually gives you an overall efficiency of 8.8%. You're taking your scarce energy resource, burning it and making use of less than 10% of the energy in that resource.
Until we are using 100% renewable or magical *cough*
Just because it takes alot of energy to create the fuel, doesn't mean the fuel isn't usable on cars. You don't see a whole lot of space shuttles running on coal.
Hydrogen will be the energy source that should suffice for a couple of centuries once we figure out how to extract energy from artificial fusion. (Note that this might include "Never", but I hope that's not the case).
Before that, hydrogen is a cumbersome, impractical, lossy way to transport energy. We might as well look into synthesizing hydrocarbons from CO2 and H2O instead of just splitting water into H2 and O2. Any hydrocarbon is less troublesome to handle than hydrogen. If we make the chains long enough, we might even end up with stuff that's pretty much identical to oil-based gasoline.
Why waste our time with producing something like "oil-based gasoline" when a diesel engine will run fine and dandy on the oil that we can just squeeze out of the end product of about half a billion years worth of plant evolution?
Biologists and architects will get us over the hump, not physicists.
Before that, hydrogen is a cumbersome, impractical, lossy way to transport energy. We might as well look into synthesizing hydrocarbons from CO2 and H2O instead of just splitting water into H2 and O2. Any hydrocarbon is less troublesome to handle than hydrogen. If we make the chains long enough, we might even end up with stuff that's pretty much identical to oil-based gasoline.
That makes no sense. The problem with hydrogen as an energy carrier is that you have to first put the energy into it to separate it from H2O. By creating energy from CO2 and H2O suffers from the same problem. You first have to put the energy into it that you plan to get out of it (different end-products than CO2 and H2O will affect the ratio of energy in to energy out, but the fundamental issue still applies).
The only reason fossil fuels are efficient is that they already exist. Essentially, they are pre-charged batteries.
That makes no sense. The problem with hydrogen as an energy carrier is that you have to first put the energy into it to separate it from H2O. By creating energy from CO2 and H2O suffers from the same problem.
Which I wasn't going to contest. My point was that handling anything that has carbon in it is much, much easier than hydrogen, which has some fairly nasty properties like diffusing through almost anything.
A practical energy carrier should be at least as convenient as natural gas. Bonus points are aw
The hydrogen economy was an idea dreamed up by those with a vested interest to divert attention and money away from more promising and immediate technologies which compete with their own investments. Still, the government got to spend lots of money.
And it underlines a point that I'd like to see raised more often: a lot of people are looking for a "magic bullet", meaning some sort of drop-in replacement for oil, whether it's bio-fuels, or hydrogen or something else. They want something that would solve all of our energy problems in one fell swoop. And that's just not going to happen.
Think about the early 19th century, for instance: oil was just one energy possibility among many others. Most people used wind power to process cereals into flour, or mechanical water power. They used coal or wood to warm themselves and candles or whale oil to light themselves. They also used solar power, for instance in salt flats. Then came steam engines -- again wood or coal -- and so on and so forth.
Of course, the 21st century is a much more advanced society, but the energy possibilities are also much more numerous: from bio-fuels to nuclear, with solar (photovoltaic and thermal), wind power, bio-mass, natural gas, tide power, etc... etc... Our technology level has progressed by leaps and bounds and may well end up covering most our needs, IF we also improve efficiency and energy savings (= no more gas guzzler for you, sorry). But the key idea here is this: the 20th century, from and energy point of view, was an historical abberation: a time when we solved most of our energy needs on one solution. The 21st century may well see us come back to a more diversified picture, and something more in line with the previous centuries.
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.
In the future (if there is one once we get our act together soon enough), the "solution" has to be a combination of solutions. Wind, Geothermal, Tidal, Nuclear (yes, Nuclear - although it's gotten a bad rap, it's actually a pretty good source), and perhaps Fusion, in addition to Hydrogen. The Earth's Oceans are a huge source of Deuterium, which can be used for Fusion (if we have it figured out), and possibly we could even use it as fuel (burning it). But I'm not sure of the effects of having slightly radioactive water vapor. Maybe it's not a good thing.
I know there's a lot of IFs, but the sooner we start...
Discovery had a good show today, outlining doomsday scenarios because of our overdependence on fossil fuels. It seems the Pentagon is actually seriously considering the implications to National Security from Global Warming and the rising cost of Oil, especially when it can involve droughts, and lots of war.
C2H5OH with [H2SO4] as a catalyst -----> C2H4 + H2O
and with that cute little double bond, I can make any hydrocarbon you want. Where do we get the ethanol? There's plenty of arable land left for now - so much so that certain governments pay their farmers NOT to plant crops. Instead of making energy to create H2, perhaps we should use the sun's energy to work for us, as we have been doing anyway for the past few billion years...
There is no "electric car with regenerative breaking". There may be a few golf-cart sized vehicles with or small cars with limited ranges, but a practical, mid-sized sedan with acceptable range on electricity only is far from a reality. Also, he seems to forgete that the batteries have to carry themselves, lowering their efficiency. Of course this is true of liquid fuels as well, but their energy density is much higher, so this issue is much less of a concern.
It seems that the title of this article should be "hydrogen infererior to magic batteries".
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.
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/drinking/ the hydrogen... I don't see that as being a big issue.
And anyway, take the hydrogen out of unclean water... Well, when that hydrogen mixes with oxygen, I gurantee you the water will be clean.
If you assume an energy efficiency of about 30%, you get roughly 11 kilowatt-hours of energy out of a US gallon of gasoline. To put 11 kilowatt-hours of energy into a battery using the electric motor and battery efficiencies indicated in the article, you need to purchase roughly 14-15 kilowatt-hours of electricity. What's that cost, retail? A hell of a lot less than buying the equivalent amount of gasoline.
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 [wikipedia.org], or through all manner of nifty renewable hydrogen sources that don't involve producing electricity and then doing electrolysis.
Pretty harmless and pretty efficient way of transporting hydrogen through a large system.
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.
As some one who works with hydrogen on a daily basis let me assure you that it is a true pain to deal with as compared to many other gases. It diffuses through many polymers and leaks are extremely dangerous due to its wide combustion mixtrue ratio range. WIth an invisible flame you can walk right into a large hydrogen fire. To get decent densities for storage you are working with either very high pressures or liquified H2. Both of these are problematic. One imposes hydrogen embrittlement issues, large heat of compression losses and many materials are useless and the other demands exquisite thermal control and imposes many other materials limitations. Hydrogen is a great fuel but only for certain uses and I would not say that everyday transport is one. It MAY be acceptable for fixed-base use in industry and less possibly in homes.
Transport batteries ( I think we all agree that is what we are discussing here) require a few things to be practical: low cost of materials and ease of fabrication, high energy density, ease of movement of the material from one vessel to another and finally ease of synthesis and also conversion efficiency. Non-toxicity is important as is the effect on the atmosphere. There are very few materials that can match or better liquid hydrocarbons.
There is one candidate that should at least be considered. Nitrous Oxide. N2O is a saturated fluid under about 750psia at room temperature and it has a density the same as hydrocarbons. This means that vessels to store it are efficient. It is non-toxic although it is an anesthetic gas. It is very safe to handle and compatible with nearly all materials. This means that the devices to handle it are cheap to make. It is a liquid so heat of compression losses for movement are minimized. If it leaks it has a distinct odor and will generally not pose an explosion hazard- at least compared to H2.
N2O is a monopropellant- in other words it will decompose to N2 and O2 when passed over a heated catalyst. It reacts very completely and almost no NOx species are produced- good for pollution. Better still it has a high flame temperature which makes for high thermodynamic efficiency. So a turbogenerator running N2O does not have to have a compressor- it can work at least part of the time off of the storage tank source pressure. Heat from the environment or directed waste heat from the exhaust can help keep the remaining N2O warm and vapor pressure high. N2O has a decent energy density but more importantly you can add any fuel and increase the power release enormously. So you power with N2O when you can and add fuel when you need to accelerate. The power increase is rapid and significant.
It does have problems though- synthesis is complex and not presently at large scale. What would be great is to develop a catalytic system that could take atmospheric N2 and O2 and under proper conditions directly synthesize N2O which could then be stored. Sounds hard to me but you never know. In any case there is no shortage of the precursors. It is however a nasty greenhouse gas. This could be its worst issue- lareg releases of unreacted N2O could be worse than CO2. But at least these are accidental and incidental- not part of everyday operation.
Anyway it is something to ponder. I always thought that a N2O vehicle with ethanol fuel assist sounded pretty good- and what a party car!
umm... (Score:4, Funny)
FRAUD Alert? (Score:5, Insightful)
FRAUD??? It's true that making hydrogen is not an efficient way to store energy for use later. However, this quote is partly nonsense: "... the production of hydrogen depends on the availability of energy and water, both of which are increasingly rare..." Water is not rare, and is could never be a problem with the production of hydrogen. I doubt that a reputable publication would print nonsense like that.
Not only is something very wrong with the article, but something is not right with the article's source, Physorg.org. Here are some Google ads at the site that seem full of fraud: "Sponsored Links (Ads by Google) -- The Next Oil Boom - See who's pumping cash by making oil for $13.21. And selling for $59. And another: Free Top Energy Profits - 5 Triple-Digit Investment Gains in Today's Alternative Energy Boom." An honest organization would never allow advertising like that, I think.
This article on the same web site seems like the beginning of fraud to me: A Printer that Delivers 1,000 Pages a Minute? [physorg.com]. There is NO printer. There is only a poorly edited article in the online (not peer-reviewed, apparently) edition of Applied Physics Letters. The idea is called JeTrix (Jet Tricks) by the supposed developers. The idea is that a printhead that covers the whole sheet of paper can print faster than one that is small.
Recently, Slashdot has been carrying discussions of "scientific breakthroughs" that are in actuality attempts to get money from investors. The Slashdot articles are, in reality, press releases for extremely poor investment "opportunities". Is a Slashdot editor taking money to run these?
Parent
Re:FRAUD Alert? (Score:5, Informative)
Parent
Re:FRAUD Alert? (Score:4, Interesting)
So by your logic its too hard to distribute clean water and too hard to extract "industrtial levels" of hydrogen from probes in the middle of the ocean, so what, just die when the oil runs out? Gee thanks, brilliant. Got any other ideas?
Parent
Re:FRAUD Alert? (Score:4, Informative)
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.
Parent
Re:Why do you need potable water? (Score:4, Insightful)
Parent
If the ads are "by Google" ... (Score:4, Insightful)
If they are using Google to sell ads they don't control the ads. Their site relates to energy issues, so ads for energy-related scams will match in the placement algorithms.
Parent
Re:House of Cards (Score:5, Informative)
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=
Parent
Re:House of Cards (Score:4, Insightful)
Alcohol is one answer, but it's not exactly perfect either.
Parent
Re:House of Cards (Score:4, Insightful)
Of course this is correct. I'm a huge supporter of biofuels as a renewable energy source (obviously) and I think carbon neutrality is a major selling point. However it's still wrong to say that Hydrogen is a carbon-free energy system when it's refined from a hydrocarbon source - especially a fossil fuel.
Reducing energy yield, yes. Reducing efficiency, no. Hydrogen/electric cars are significantly more efficient than gas ICE cars. So while you have less energy to use when you put the fuel in the vehicle, you use less energy to get the same output from the vehicle using hydrogen.
While burning hydrogen may be slightly more efficient, the energy density is significantly lower resulting in more fuel being burned for the same output. In the end, pound-for-pound, Hydrogen seems to offer no significant advantage.
When you consider the requirements to manufacture and store the Hydrogen, I challenge that the efficiency from energy source to point of use is actually very poor.
People love to shoot down alternative fuels because they aren't able to replace ALL of the vehicles on the road.
Hydrogen is not an alternative fuel. That's the problem. So far, whatever source of energy you're using to make the hydrogen - electricity, natural gas, etc. - can be better used directly instead of pissing away half of it using hydrogen as an intermediate.
I completely agree that there is no single solution, but I do not agree that pure Hydrogen as a primary link in the energy flow is ever going to work. Biofuels are a much safer bet, being renewable, carbon-neutral, 100% compatible with existing infrastructure and closer to the energy source.
=Smidge=
Parent
Re:House of Cards (Score:4, Interesting)
You seem to be missing the two fundamental points of a hydrogen economy.
1) A hydrogen economy is not bound to a specific liquid fuel. Ultimately, a hydrogen economy is an electric one. Not many are predicting "peak electricity" any time soon.
2) A hydrogen economy is very efficient. That is, to say, electric vehicles (which is what hydrogen-fuelled vehicles are) can easily recover energy, electric engines are very efficient, fuel cells are up to ~70% efficient, electrolysis of water is ~90% efficient, etc.
Of course, in the mean time, until thermolysis of water (say, from nuclear power) or farmed hydrogen (say, from genetically engineered bacteria) is available, producing the hydrogen is a somewhat wasteful stage that's reliant on natural gas. Only "somewhat", however. Natural gas reforming produces H2 and CO. CO can be burned for heat. As a result, apart from incomplete combustion, all of the energy of the natural gas either goes to H2 or heat. Heat can be used to do work. Indirectly (subject to carnot cycle losses), it can generate power. More usefully, however, is it can heat processes that need heat inputs -- industry or even home water/house heating. In such a case, you only "lose" a tiny amount of the natural gas's energy.
Of course, even if you consider all of non-H2 energy wasted, as this article does, you're left with the following possibilities:
1) 30% efficiency on your typical ICE gasoline engine.
OR
2) 25% efficiency on your typical natural-gas derrived hydrogen engine, which is automatically a "hybrid" and can thus save power by regenerative braking. And, since it uses natural gas for the hydrogen, which is currently more available than oil, it reduces stress on the oil market. If natural gas prices rise too much, pressure on natural gas markets can be allieviated by switching from natural gas power plants to coal/nuclear (as happened with the oil-driven power plants in the 70s).
Is the second option really that bad -- present day? Especially with some of the new high-density hydrogen storage systems hitting the market? I think not.
As an aside, I ran into an interesting proposal for hydrogen storage that costs 1/3 as much as conventional storage tanks: commercial-scale wind turbines. They're huge hollow shafts. The extra cost to make the turbine able to hold hydrogen is something like 85k$, and an equivalent-sized tank costs something like 250k$.
Parent
sun and wind (Score:5, Insightful)
but even this will be useless if we don't put serious brain power into improving the eficiency of our gadgets/cars/homes/etc.
Re: (Score:3, Insightful)
sun and wind power are, IMHO, the alternative to oil and coal
Wind won't work outside of a very few areas that have the kinds of sustained winds to make it workable. In general, it just takes up too much physical space for the energy it generates.
Solar is potential workable, but not with single-crystal silicon wafers. Those actually require quite a bit of energy to create, and take (I believe) over a year to "pay back" that energy. Recent research into nanocrystalline materials has more potential there
Re:sun and wind (Score:4, Insightful)
Why impose additional constraints on new solutions to old problems? Hydroelectric power also won't work outside a very few areas where there is enough water and elevation difference, coal thermoelectric plants are impractical outside areas where you can strip mine coal, nuclear fission power plant is not feasible where you don't have uranium available (or water for cooling for that matter, or where it is IMBY). All this "downsides" didn't stop us from building and using each one of them. Why should we now suddenly make such an exception for wind power plants only?
Ever heard of Niagara Falls hydroelectric plant and Nikola Tesla? Back then, the guy demonstrated that energy can be harvested in remote locations, then conducted to areas of deployment.
Unrelated to that, but similar in paradigmatic sense, note that petroleum is used throughout the world, even though it is obtained only from handful of regions of the planet.
So, the only thing that actually matters for whichever energy production is: is it doable anywhere?
Parent
Solar, wind, nuclear and energy efficiency (Score:4, Insightful)
Actually both are space hogs, especially if you are talking about actual wind or solar 'powerplants'. However each has the potential to produce say... very rough guess here... up to 10% of the energy needs. In Europe wind is extensively used, farmers often set up wind generators on their fields and sell the electricity they don't need to the energy companies for extra income. If you drive through Denmark, Holland, or N-Germany you will see wind generators by the dozen in the wheat fields you drive through. I don't think either wind nor solar will replace coal and oil for all sorts of reasons of which the physical space they take up is only one reason, they will remain important supplementary energy sources. Large solar power plants are not all that common here in Europe but people have begun to combine improved insulation of their houses/apartments with measures like mounting solar cells on the roof to reduce the amount of energy they have to draw off the electric network for heating/cooling or lighting in their houses. Basically I think we can get far by encouraging the use of wind and solar and combining those with measures aimed at increasing the efficient use of energy but even all those measures together will never enable us to replace oil and coal. Unless somebody finds miraculous new energy source and invents room temperature super-conductors in the near future, conventional Nuclear power may prove the only viable way to phase out fossil fuel use in power plants. Nuclear leaves nasty waste products that will be hard to deal with but at least it doesn't cause a rise in sea levels and climate change. The choice we have at the moment is:
It's a choice between bad and worse.
Parent
Use farmland (Score:4, Informative)
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).
Parent
Re:sun and wind (Score:5, Insightful)
How about putting some serious brainpower to changing cultural values? How much fucking space, heat, energy, electricity is wasted every year because each family/individual has a house/apartments much bigger then they need yet no people populate the extra empty rooms during the year, etc? Society in their desire for privacy / personal space creates a huge tonne of fucking waste simply through their animal prejudices and "preferences" (read programmed evolutionary emotional responses), we could save a TONNE of money and resources of we did something to develop superior cultural values. How much money would be saved on social programs if governments gave tax breaks to people that took the disabled, homeless, etc into the free space in their homes rent free, etc? How much good could come if people simply weren't dogs infected with the backward behavioural baggage of evolution.
Parent
Simply replace income tax with an energy tax (Score:5, Insightful)
No changes to human behaviour required.
Parent
Re:sun and wind (Score:4, Insightful)
Maybe we should all live in a hive, possibly with a monarch as a king?
How about we sleep only in standing closets, or pull out rolling beds?
Maybe we could all live life in a gigantic bunk house with public showers?
Why not get rid of cars and bus's and airplanes and boats entirely? Heck, weve got internet now, everyone can telecommute right?
in fact, why not just jack everyone into a grid
And maybe we could tweak that virtual world to remain always near perfect, but not quite perfect.
Humanity like most life is designed to consume resources as much as it can, the gambit is wether or not we can find a way to maintain our growth through such consumption. Compression and self-lessness are only positive if they are natural or necesary. Compelling our current society to live in pods would be foolish, detremental, and likely a catastrophe. While condensed living is a requirment in most major population centers, youd be surprised at just how comfy people who live in rural or semi-rural europe/asia/America/Africa are in terms of space.
This planet is BIG... REALLY BIG... on a magnitude thats hard to describe. You could suggest we all go underground too, with equally disasterous results. But te key to our "evolution" is to be the first bit of life to succesfully get off this rock in a self sustainable manner.
Which is exactly why population density not being a preffered condition is a good thing, it forces us to open up new frontiers and search for more space... you know... doing that "life" thing.
We keep growing like this and we might die.... We stop growing, and we will die for sure.
Parent
Re:sun and wind (Score:5, Insightful)
It all depends on who you regard as "rogue nations running around doing anything they want". From where I'm sat, that description looks more like Bush's USA than Iran.
Parent
Re:sun and wind (Score:5, Informative)
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.
Parent
Re:sun and wind (Score:4, Insightful)
And the author of this study makes a trivially false claim in this regard: "We have to solve an energy problem not an energy carrier problem."
No, we have an energy carrier problem. We have all kinds of sources of energy. Wind, wave and most of all solar are more than abundant enough to supply the world's energy needs if we could just package and transport that energy with reasonably high volumetric and gravimetric density. If those sources are not enough then nuclear, for all its problems, is perfectly capable of filling the gap. But all of these sources most easily produce electricity, which has limited utility as a carrier of energy, particularly for transportation. The energy density of batteries, to say nothing of the conversion efficiency at anything like full discharge, is far worse than hydrogen.
Beyond that, the author makes a strong claim about the economic feasibility of the hydrogen economy. We all know what an exact science economics is, and how economists routinely make accurate and empirically validated predictions of the future of technological trends. So the author is arguing about the wrong problem and reaching an implausibly strong conclusion.
Parent
Eh? (Score:5, Insightful)
Re-use (Score:5, Insightful)
Overall consumption of energy has to go down... (Score:5, Insightful)
Re:Overall consumption of energy has to go down... (Score:5, Insightful)
-Oil looks cheap because we are using in a few centuries the production of millions of years.
-Wind or solar energy comes free, but to use them, you need devides that need to be built, maintained and trashed, and due to their power source, they can have significant downtimes. Solar pannels also contains a lot of dangerous materials (As, Ge, Ga...) and their production causes some nasty pollution.
-Nuclear power is probably the best we can have today for fixed power generation: we have largely enough uranium to wait for the fusion reactors and the generated pollution doesn't go into the atmosphere and therefore can be processed, but there will always be a risk with that.
And of course, for the portable energy
-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.
Parent
Re:Overall consumption of energy has to go down... (Score:4, Informative)
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)!
Parent
Re:Overall consumption of energy has to go down... (Score:4, Informative)
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%.
Parent
Battery (Score:4, Informative)
A particularly bad Battery (Score:5, Informative)
Parent
Re:A particularly bad Battery (Score:5, Funny)
Parent
What difference does energy efficiency make? ... (Score:3, Informative)
If we use solar, wind and tidal energy to charge the hydrogen batteries, what difference does energy efficiency make, so long as current and future energy needs can be met?
Well, you take your energy as hydrogen, I'll take it as electricity at 1/4 of the price...
And it gets worse. Assume we're not going to use 100% *cough* renewable electricity. Assume your energy comes from a local coal power station. They're about 35% efficient, so your 25% efficient battery actually gives you an overall efficiency of 8.8%. You're taking your scarce energy resource, burning it and making use of less than 10% of the energy in that resource.
Until we are using 100% renewable or magical *cough*
From the article (Score:4, Insightful)
There. nuff said.
Why do they have hydrogen cars in Finland then? (Score:3, Insightful)
Hydrogen misunderstood. (Score:5, Insightful)
Before that, hydrogen is a cumbersome, impractical, lossy way to transport energy. We might as well look into synthesizing hydrocarbons from CO2 and H2O instead of just splitting water into H2 and O2. Any hydrocarbon is less troublesome to handle than hydrogen. If we make the chains long enough, we might even end up with stuff that's pretty much identical to oil-based gasoline.
Re: (Score:3, Insightful)
Why waste our time with producing something like "oil-based gasoline" when a diesel engine will run fine and dandy on the oil that we can just squeeze out of the end product of about half a billion years worth of plant evolution?
Biologists and architects will get us over the hump, not physicists.
Re:Hydrogen misunderstood. (Score:5, Insightful)
The only reason fossil fuels are efficient is that they already exist. Essentially, they are pre-charged batteries.
Parent
Re: (Score:3, Informative)
Which I wasn't going to contest. My point was that handling anything that has carbon in it is much, much easier than hydrogen, which has some fairly nasty properties like diffusing through almost anything.
A practical energy carrier should be at least as convenient as natural gas. Bonus points are aw
Well, yeah, wasn't that obvious? (Score:4, Interesting)
water is not scarce. (Score:5, Insightful)
No surprise here. (Score:5, Insightful)
Think about the early 19th century, for instance: oil was just one energy possibility among many others. Most people used wind power to process cereals into flour, or mechanical water power. They used coal or wood to warm themselves and candles or whale oil to light themselves. They also used solar power, for instance in salt flats. Then came steam engines -- again wood or coal -- and so on and so forth.
Of course, the 21st century is a much more advanced society, but the energy possibilities are also much more numerous: from bio-fuels to nuclear, with solar (photovoltaic and thermal), wind power, bio-mass, natural gas, tide power, etc... etc... Our technology level has progressed by leaps and bounds and may well end up covering most our needs, IF we also improve efficiency and energy savings (= no more gas guzzler for you, sorry). But the key idea here is this: the 20th century, from and energy point of view, was an historical abberation: a time when we solved most of our energy needs on one solution. The 21st century may well see us come back to a more diversified picture, and something more in line with the previous centuries.
Water shortage? (Score:4, Informative)
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.
Not Hydrogen Alone (Score:4, Insightful)
In the future (if there is one once we get our act together soon enough), the "solution" has to be a combination of solutions. Wind, Geothermal, Tidal, Nuclear (yes, Nuclear - although it's gotten a bad rap, it's actually a pretty good source), and perhaps Fusion, in addition to Hydrogen. The Earth's Oceans are a huge source of Deuterium, which can be used for Fusion (if we have it figured out), and possibly we could even use it as fuel (burning it). But I'm not sure of the effects of having slightly radioactive water vapor. Maybe it's not a good thing.
I know there's a lot of IFs, but the sooner we start...
Discovery had a good show today, outlining doomsday scenarios because of our overdependence on fossil fuels. It seems the Pentagon is actually seriously considering the implications to National Security from Global Warming and the rising cost of Oil, especially when it can involve droughts, and lots of war.
Hydrogen is out... (Score:5, Insightful)
C2H5OH with [H2SO4] as a catalyst -----> C2H4 + H2O
and with that cute little double bond, I can make any hydrocarbon you want. Where do we get the ethanol? There's plenty of arable land left for now - so much so that certain governments pay their farmers NOT to plant crops. Instead of making energy to create H2, perhaps we should use the sun's energy to work for us, as we have been doing anyway for the past few billion years...
An unfair comparison (Score:3, Informative)
It seems that the title of this article should be "hydrogen infererior to magic batteries".
Whoopdie doo...
Hydrogen a white elephant (Score:5, Informative)
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.
Finally an article that makes some sense... (Score:4, Informative)
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.
Misguided analysis (Score:4, Informative)
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 [wikipedia.org], or through all manner of nifty renewable hydrogen sources that don't involve producing electricity and then doing electrolysis.
Re:my car is eating sugar! (Score:5, Informative)
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.)
Parent
Re:hydrogen may be inefficient BUT (Score:5, Interesting)
Transport batteries ( I think we all agree that is what we are discussing here) require a few things to be practical: low cost of materials and ease of fabrication, high energy density, ease of movement of the material from one vessel to another and finally ease of synthesis and also conversion efficiency. Non-toxicity is important as is the effect on the atmosphere. There are very few materials that can match or better liquid hydrocarbons.
There is one candidate that should at least be considered. Nitrous Oxide. N2O is a saturated fluid under about 750psia at room temperature and it has a density the same as hydrocarbons. This means that vessels to store it are efficient. It is non-toxic although it is an anesthetic gas. It is very safe to handle and compatible with nearly all materials. This means that the devices to handle it are cheap to make. It is a liquid so heat of compression losses for movement are minimized. If it leaks it has a distinct odor and will generally not pose an explosion hazard- at least compared to H2.
N2O is a monopropellant- in other words it will decompose to N2 and O2 when passed over a heated catalyst. It reacts very completely and almost no NOx species are produced- good for pollution. Better still it has a high flame temperature which makes for high thermodynamic efficiency. So a turbogenerator running N2O does not have to have a compressor- it can work at least part of the time off of the storage tank source pressure. Heat from the environment or directed waste heat from the exhaust can help keep the remaining N2O warm and vapor pressure high. N2O has a decent energy density but more importantly you can add any fuel and increase the power release enormously. So you power with N2O when you can and add fuel when you need to accelerate. The power increase is rapid and significant.
It does have problems though- synthesis is complex and not presently at large scale. What would be great is to develop a catalytic system that could take atmospheric N2 and O2 and under proper conditions directly synthesize N2O which could then be stored. Sounds hard to me but you never know. In any case there is no shortage of the precursors. It is however a nasty greenhouse gas. This could be its worst issue- lareg releases of unreacted N2O could be worse than CO2. But at least these are accidental and incidental- not part of everyday operation.
Anyway it is something to ponder. I always thought that a N2O vehicle with ethanol fuel assist sounded pretty good- and what a party car!
Parent