Google Engineers Say Renewable Energy ‘Simply won’t work’

[Tom Ligon]

Also, I would expect the hydrogen to be used for powering fuel cells, and I wonder what odorant would not be an issue for the fuel cell? But, I am wondering out of total ignorance on the subject, it's just that there are robust catalysts and catalysts that are picky.

Probably. An odorant such as a mercaptan would have sulfur, the mortal enemy of catalysts. But, as you say, hydrogen is a tiny and slippery little molecule, and a permselective membrane should do the trick.

For big energy storage facilities I don't see these objections as show-stoppers. H2 is non-toxic and environmentally benign once dissipated. The combustion byproduct is desirable. Professionals handling it, no coupling and uncoupling of lines and tanks, no odorant necessary. The criteria are: 1) enough hydrogen generating capacity to take the output of the intermittent resource, 2) sufficient fuel cell or other generating capacity to provide useful steady output to the grid, and 3) fuel storage for as much time as you think you need it, plus a reserve.

I think this approach probably scales better than electrochemical batteries (as AES was using on the Mount Storm/New Creek wind farm). The difference is you can tank the hydrogen, you are not limited to just the electrolyte in the batteries. Although we have discussed using external electrolyte storage here before. The thought is, once you have the basic plant running at the needed load capacity, increasing storage time means adding more tanks, not adding more fuel cell capacity.

But given my druthers, I'd still rather have Polywells running the grid.

[paperburn1]

Hydrogen, hydrogen, hydrogen. Here's an idea for the brain trust. What would it take in solar panels to run one of those CO2 to liquid fuel converters. Until we come up with a better battery technology I think that would be the most efficient way to use solar power that could be easily distributed to the general public.Just turn it into a liquid fuel like gasoline now you have portability, Usability, and hopefully a safer product than hydrogen. Just a random thought, does anybody else got anything?

[mvanwink5]

Short term, we have what we have, medium term would be start of fusion / advanced fission introduction, long term fusion / fission build out. Solar, wind, hydro, etc, in select niches, and will always be there, we still have horses and buggies. Hydrogen is definitely ok for industrial applications, but then that is a lot of work just to extend the use of niche products. I think Elon Musk is right about battery power for autos, trucks maybe, maybe something else? However, predicting the future is a dubious business, I'd be willing to go out on a limb and bet a solid 50 cents on mine, and one breakthrough and there you have it, whatever it is.

[GIThruster]

Hydrogen isn't really useful for mobile applications such as cars, and it's a huge hazard and expensive to handle as liquid because it is so cold. Even then, it does not have the energy density of other fuels by volume--only by mass--which requires huge volume containers. And when you burn it, it mixes with things other than O2 in the air and you get searing hot corrosive gasses that press the boundaries of materials science to handle the stuff. It also requires very heavy, thick walled tanks so the lightness benefit of the element is lost through combination with heavy steel tankage. Methane is a better solution for mobile applications in about a dozen ways.

[kunkmiester]

Last I knew the solution people were going for was to dissolve it, like they do with acetylene and acetone. I remember a long time ago several sites were going bananas because it was the big break to make it work well. Then not a peep.

[palladin9479]

Natural gas is also colorless (when a vapor) and odorless, in its natural form. The providers -add- oderants to it so you can more easily tell when a leak is occuring, without the need for any detectors other than the nose (though having them is probably safer).

There were lots of arguments when the automobile first started getting traction (no pun intended). The arguments were between whether it should be fueled with gasoline or hydrogen, and what would happen with each in the case of a crash. Personally, I'd rather be in a vehicle where the fuel leaked up, away from the scene of the crash, than in one where the fuel pools underneath.

And you'd be a fool for it.

Gasoline is a far safer fuel then Hydrogen gas due to its vapor pressure. Gasoline itself doesn't burn, like other hydrocarbon fuel it needs to be mixed with oxygen and then vaporized for combustion, Hydrogen on the other hand can explode by merely introducing Oxygen and a spark. So if two cars with Hydrogen fuel tanks crashed together at high speeds the probability of an explosion is fairly high. Two hydrocarbon powered cars crash into each other at high speeds and zero chance of an explosion. Hollywood is total bullshit, they make everything explode because it's more dramatic that way. In actual car crash's the worst that can happen is leaked fuel catch's fire and burns the vehicle, no sudden explosions throwing good looking actors back 10 feet.

Pure hydrogen is a very dangerous thing to keep around and shouldn't be trusted in the hands of any non-licensed person. Definitely not in the hands of average consumers. And to be perfectly honest, there is zero reason to go away from hydrocarbon based transportation fuels. It's cheaper for us to refine them from crude oil but if push comes to shove we can easily synthesize them from freely available Hydrogen, Oxygen and Carbon. Just need a source of really cheap energy, like say a small fusion reactor. The US Navy already has a process to synthesize diesel from Ocean water, they got nukes so energy isn't much of an issue to them.

[Tom Ligon]

Yes, Hollywood likes blowing everything up, and that includes some mighty foolishness regarding gasoline tanks.

But ...

Gasoline at room temperature produces vapors that will ignite, i.e. it is flammable. So while the liquid itself doesn't ignite, the vapor above it will. If this ignition occurs with a fuel air mixture within the explosive limits, and contained, expect an explosion. The energy release can supposedly reach over 900 sticks of dynamite per gallon of gasoline.

Diesel and kerosene are combustible, but not flammable. They do not produce sufficient vapor at room temperature for the vapors to ignite, althought they can ignite if drawn onto a wick, or heated sufficiently.

Gasoline vapors have produced some mighty blasts. This includes an entire town in which a gas station had leaked into the sewers, and some stray spark ignited it. The sewers blew, destroying nearly every street in the town. In long tubes, such an explosion isn't just rapid burning, you can get shock waves forming, and true detonation.

Just so you know, to produce a spectacular fireball in all those Hollywood explosions, the favorite fuel is gasoline. The conditions may be fake, but it really does that when you get the conditions right.

[palladin9479]

Hydrogen, hydrogen, hydrogen. Here's an idea for the brain trust. What would it take in solar panels to run one of those CO2 to liquid fuel converters. Until we come up with a better battery technology I think that would be the most efficient way to use solar power that could be easily distributed to the general public.Just turn it into a liquid fuel like gasoline now you have portability, Usability, and hopefully a safer product than hydrogen. Just a random thought, does anybody else got anything?

Lots of different people are working on this problem from different angles. They are all focused on "combating the evil CO2!!" so are taking a rather round about approach in their efforts to be "green". It would be easier to convert from CO2 to CO and store that for later use as it's feedstock for further hydrocarbon production. The goal would be to make methane, CH4, but you'd need a bit more chemistry then your average household occupant would be capable of.

[palladin9479]

Yes, Hollywood likes blowing everything up, and that includes some mighty foolishness regarding gasoline tanks.

But ...

Gasoline at room temperature produces vapors that will ignite, i.e. it is flammable. So while the liquid itself doesn't ignite, the vapor above it will. If this ignition occurs with a fuel air mixture within the explosive limits, and contained, expect an explosion. The energy release can supposedly reach over 900 sticks of dynamite per gallon of gasoline.

Diesel and kerosene are combustible, but not flammable. They do not produce sufficient vapor at room temperature for the vapors to ignite, althought they can ignite if drawn onto a wick, or heated sufficiently.

Gasoline vapors have produced some mighty blasts. This includes an entire town in which a gas station had leaked into the sewers, and some stray spark ignited it. The sewers blew, destroying nearly every street in the town. In long tubes, such an explosion isn't just rapid burning, you can get shock waves forming, and true detonation.

Just so you know, to produce a spectacular fireball in all those Hollywood explosions, the favorite fuel is gasoline. The conditions may be fake, but it really does that when you get the conditions right.

The key to that comment was the pressures involved. Gasoline is stored at room temperature and pressure, it will slowly sublimate into a vapor if left along for long enough. Note the use of the term "long enough", meaning not instant, nor in a fifteen minute period of time. It's impossible for two cars colliding to create a gasoline explosion, there isn't enough time for the gasoline to vaporize in a sufficiently contained area for produce the conditions for an explosion. Hydrogen on the other hand comes prepackaged in such conditions, every pressurized hydrogen tank is bomb waiting for a rupture + heat to explode.

This is why hydrogen is a very bad idea as a transportation fuel. In real world usage liquid fuels are much safer.

Any why on earth would you want to use Hydrogen anyway? CHO chemical bonds contain more energy and are safer to use. There seems to be an unsubstantiated amount of hate directed at CHO fuels for no reason other then it's derived from stored high energy hydrocarbons. It really seems a desire to "just do something!!!" rather then outlining actual effects, root cause and solution.

[Tom Ligon]

Ack, waited to long to add this.

Just so you know, in spite of my rant just now about gasoline, I like it, use it, have three gasser vehicles, two lawn mowers, a chain saw ....

My point is that we handle this dangerous stuff daily and think nothing of it. But bring up hydrogen and everybody goes all Hindenburg over it. Wooooo, dangerous. I've worked with hydrogen for years. It is a pussycat.

I had a character in a story once, who had just had an experimental rocket engine blow up. "Well, Tom," he said, "rocket fuel is kinda like a chain saw. If it warn't dangerous, it wouldn't be very useful."

Gasoline and hydrogen are both like that. Deal with it.

You want dangerous? Try liquid oxygen. Even bottled oxygen,

[palladin9479]

My point is that we handle this dangerous stuff daily and think nothing of it.

Average person doesn't. People who are trained or at least have some lab / shop experience do and we follow safety procedures to ensure no accidents happen, but your average person doesn't. Transportation solutions need to be designed around the lowest common denominator, aka "Joe six pack" or "Soccer mom Kate". They wake up, get showered / dressed, walk outside and drive their portable bomb to work. Vehicle and fuel designs need to be engineered to make that portable bomb less likely to detonate accidentally. Having a hydrogen fuel tank (stored under high pressure) makes that infinitely more likely to happen then having a CHO derivative fuel tank. Though to be fair, pure Oxygen doesn't really burn or do much of anything, it needs to be mixed with a reactive substance first. O2 is only dangerous when it's mixed with something else, of course when that happens it tends to greatly amplify the combustive effects of whatever it was added to. A hydrogen explosion is dangerous but a hydrogen explosion that's done in the presence of pure O2 (say from a H2 and O2 tank being next to each other for some strange reason) would be greatly amplified to catastrophic proportions.

[Tom Ligon]

Then we won't be letting you handle any oxygen bottles. Do you know that opening a valve on a compressed oxygen supply too fast can ignite the tubing, even metal tubing, causing a fire like a welder's torch? Or that liquid oxygen mixed with flour is a high explosive capable of blowing up mountains? And by your criterion, H2 is only dangerous if mixed with an oxidizer.

Pure oxygen killed the crew of Apollo 1.

But my original proposal was that hydrogen MIGHT make a better means of energy storage for intermittent "renewable" power sources than batteries. I gave the reasons earlier, but to recap, this is a fixed installation, professionally managed, and the probable equipment would be photocatalytic assist for electrolysis, and recombination in fuel cells. For fuel cell use, it would be foolish in the extreme to convert to a hydrocarbon, because to use hydrocarbons, a fuel cell has to strip off the hydrogen and discard the carbon.

And without better storage technology, terrestrial wind and solar are a headache of marginal value at best. I say that as a solar user.

Hydrogen is a fine rocket fuel. H2/LOX gives the best specific impulse of any chemical rocket fuel combination, except maybe for a few exotic tripropellants. Running "hydrogen rich" the space shuttle main engines achieved 460 seconds Isp. The reason it is so good is the low molecular weight of the exhaust product, water, which gives a high exhaust velocity.

Hydrogen could be used in internal combustion engines, but I'd go for fuel cells running an electric car. A Tesla would be a hoot run this way, and I think you could probably finally get decent range with such a system.

Beyond that, for a motor fuel, there is certainly merit to synthesizing a hydrocarbon fuel. But I think you'll find you need an economical source of hydrogen to do it.

And there are hydrogen storage systems in the works to store hydrogen at low pressure. How good they are I don't know.

[palladin9479]

All materials under high pressure are dangerous, Oxygen is no different. The air your breathing right now is 20~21% oxygen and there are medical procedures for breathing 100% Oxygen (or close to it). A ruptured tank of O2 will not explode as nothing oxidizes Oxygen. Now if you happen to have combustion happening nearly, or another chemical that reacts exothermically with Oxygen then the sudden release of 100% O2 could very well excite that chemical into a reaction. It's a minor difference but an important one and the reason you store O2 separate from anything else, too many things that are mildly dangerous at 20% O2 levels become wildly dangerous at 90% O2 levels.

But my original proposal was that hydrogen MIGHT make a better means of energy storage for intermittent "renewable" power sources than batteries.

Possibly, would depend on the efficiencies and how you convert it back into useful energy. Fuel cells are about as efficient as thermal dynamo (40~60%) so your wasting a large portion of your stored energy as low level heat, a battery on the other hand would retain most of that energy for later use. Unless there is some sort of radical advance on fuel cell technology that enables 90%+ efficiency then using it as an intermediary energy storage technology doesn't seem that good.

[krenshala]

A ruptured tank of O2 will not explode as nothing oxidizes Oxygen. Now if you happen to have combustion happening nearly, or another chemical that reacts exothermically with Oxygen then the sudden release of 100% O2 could very well excite that chemical into a reaction. It's a minor difference but an important one and the reason you store O2 separate from anything else, too many things that are mildly dangerous at 20% O2 levels become wildly dangerous at 90% O2 levels.

I think you are forgetting that O2 reacts with just about everything. You must have O2 to have oxidation. If an O2 tank ruptures, the problem isn't "nothing oxidizes Oxygen", the problem is that Oxygen oxidizes just about everything (ignoring the issues of high-pressure and/or cryogenic storage ruptures). You don't need anything else but an ignition source to get an oxygen fire/explosion (e.g., the Apollo 1 fire Tom referenced earlier). For almost all other substances you must have the ignition source and oxygen to get a fire, let alone an explosion.

[Tom Ligon]

Technically, you can oxidize oxygen. Fluorine will do it ... in a lab safety course the consequences of mishandling compressed fluorine were described ... it will burn oxygen with a blue flame. But, of course, you have to go out of your way to do this.

The rocket scientist I based the character above on had some wild ideas for getting more punch out of rocket fuel, including switching from liquid oxygen to (pick your favorite nutty option):

Liquid ozone
Liquid fluorine
Liquid tri-fluorine (the ozone analog of fluorine)

I repeat, if you think bottled oxygen or liquid oxygen are innocuous to handle, I strongly urge that you take a lab safety course that covers these. Oxygen, that lovely life-giving gas, has a vicious side.