Efficiently Harvesting Hydrogen Fuel From Sun Using Earth-Abundant Materials

I continue being a naysayer about hydrogen. It looks like a perfect fuel, only produces water vapor. Makes all the greenees happy.

BUT you have to store this stuff. And it is way beyond it's critical temperature for standard earth conditions. And the nominal pressure vessel that can be manufactured to hold it is 4400 PSI working pressure (30.3 mega Pascals). How many pressure cycles before you exceed fatigue stress?

And then there are lay people that will touch some sort of the process of storage or transfer, that will cause a big explosive fireball. Even if these are trained "technicians" they still will screw up. And it's too unforgiving of a material.

So store it in a dewar in liquid state, just makes a bigger fireball when something goes wrong.

And for any vehicle use, you can't get enough range on large tanks.

Why is it you don't see high pressure natural gas used for civilian auto use? I've only seen it used by municipalities on buses. (This is used in Europe, but how wide spread is it?)

Just not enough statistical use of high pressure fuel to see how horrible the accident rate will be.

They said the same things about gasoline....You sell the materials engineering sector short...

" A recent study by Dutch researcher Robin Gremaud has shown that metal hydride hydrogen tanks are actually 40 to 60-percent lighter than an equivalent energy battery pack on an electric vehicle permitting greater range for H2 cars.^[77] In 2011, scientists at Los Alamos National Laboratory and University of Alabama, working with the U.S. Department of Energy, found a new single-stage method for recharging ammonia borane, a hydrogen storage compound.^[78][79]"

http://en.wikipedia.org/wiki/Hydrogen_vehicle

SE, I know we can do this, but will it be a commercial success?

In the same wiki article, was this on the energy efficiency of making, storing, then converting back to electricity:

"Volkswagen's Rudolf Krebs said in 2013 that "no matter how excellent you make the cars themselves, the laws of physics hinder their overall efficiency. The most efficient way to convert energy to mobility is electricity." He elaborated: "Hydrogen mobility only makes sense if you use green energy", but ... you need to convert it first into hydrogen "with low efficiencies" where "you lose about 40 percent of the initial energy". You then must compress the hydrogen and store it under high pressure in tanks, which uses more energy. "And then you have to convert the hydrogen back to electricity in a fuel cell with another efficiency loss". Krebs continued: "in the end, from your original 100 percent of electric energy, you end up with 30 to 40 percent."^[100]"

It probably is moot if the original electric energy is "free" solar, wind, hydro, or geothermal. This method from the OP may reduce the input energy to make the hydrogen. But then I could not find a link to what the pressure the hydride reduced the pressure to in the tank. There's also the anti green of mining the materials, manufacturing the tank, and building the vehicle around using fuel cells (which can be said about any machine we make today). In the end, this machine is not the same as a fossil fuel vehicle that can travel 300-400 miles on one tank (so how safe is this, and how much complexity do you need to boil the hydrogen off the hydride surface), of gasoline (diesel), which is filled safely. It's a paradigm to compare electric (battery or hydrogen) to fossil fuel. One can easily travel long distances, the other is short commutes with today's storage technologies.

OK I have maybe 40 more years of life if I'm lucky, I don't think that hydrogen will be a commercial success in that period of time.

When I start hearing governments say that to fix the worlds problems we need to reduce population, then I may believe hydrogen is viable, as there is a limited amount of energy that you can dedicate to hydrogen production.

You seem to have completely ignored the fact that we will eventually reach peak oil, the point that gasoline becomes $20 a gal....Hydrogen production and the technology that would enable wide usage for fuel, is becoming cheaper, and at some point will become cheaper than gasoline mile for mile.....the main advantage of hydrogen over pure electric is speed of refill/recharge, and universal compatibility by nature...add to all that the reduction in Co² and other polluting gases associated with gasoline and diesel and other fossil fuels, and you can see this is where we are headed as a society....Certainly electric vehicles are the destination, it's how they will be designed and built that will continue to evolve....

If we get to that point, personal vehicles (at the current per capita count) will be gone.

I'm more of the belief that hydrogen production will be for storing the renewable energies. And the use will be for grid production, and this used to power mass transit.

I don't know that you can support an unending demand of any energy type without population limits. But as long as the money pump is working, all is well.

I recall what $4.75/gal did to the economy a few years back. I don't see hydrogen production cost that can keep the cost of living within the ability of those at the middle class (and lower) income to survive. I see hydrogen as an energy source to be many years in the future as now fracking looks to be able to provide the next centuries worth of 'cheap' energy.

I certainly see that carbon emission, changes the fossil fuel game.

The hydrogen solution, has limits on how much we transfer our expendable income to energy, as this limits consumption of all things that fuel the economy.

I see no evidence, at this moment in time, hydrogen is viable vs easy to "suck out of the ground" fossil fuels.

That's my crystal ball view. But I'm probably reading it wrong.

Well everything can be thought of in terms of energy cost to produce....Energy cost is the boiler plate of the economy, and nuclear production of hydrogen is potentially the cheapest portable energy supply that can reach the scale necessary to meet the goal...Once that becomes realized, then the technology will move quickly towards that goal, as the materials are developed to enable deployment...We can see this taking place today with the electrically powered car, most will be a first step hybrid, but eventually all cars will have an electric component to the drive train....and further in the future all electric.....the electricity will be supplied starting with batteries moving to fuel cells....The population growth has shown to be self-regulating....Here in the US the population growth is slowing to a crawl, and soon will level off, as in other mature developed countries....

Very recently a major R&D center (Stanford?) designed a substrate

using nickle/iron that allowed electrolosis of water with a 1.5 volt

battery! This could lead to a way to store WATER in the tank, and

generate hydrogen on demand. This could be used to drive fuel cells

for electric propulsion.

For that matter, why not simply store energy as Aluminum metal, then use the CCHOD scheme (proven to make wads of hydrogen with no oxygen in it, other than smalls of water vapor) to instantly provide upon demand, all of the hydrogen pressure and flow rate needed by any engine (depending on the reactor design for the CCHOD). The Aluminum hydroxide has a place in this world, or can be recycled back to Aluminum rather simply and I must say more easily than other metals such as magnesium. Or just use the hydrogen production scheme to make liquid fuels. Or run your fuel cells, but I don't think fuel cells have reached maturity, although catalyst research seems to be moving away from platinum (finally).

https://www.hyundaiusa.com/tucsonfuelcell/

I just posted this a few days ago. I have faith that we can get away from gasoline, as long as idiot politicians don't lock us into stupid. It's not hopeful...they won't even admit that ethanol was a waste of time and money, and now there are so many billions of dollars associated with it, politicians will be secretly fighting anything that threatens the IC engine.

http://evworld.com/article.cfm?storyid=1756

Anything that threatens the money flow to selected agribusiness firms, and the politicians that aim that money at them, in order to get re-elected...

a politician and an engineer once stood next to a hole, and they began to argue which is the best way to fill the hole. The politician made it a law to pour money into the hole from now on. The engineer dug another hole next to it, and started removing money from the bottom of the first hole. Problem solved.

That is why you take the hydrogen and liquify coal with it to make gasoline, silly man!

It is the HINDENBURG albatross..."Oh, the humanity..."

See the movie....Why aren't the electrodes screens instead of plates..?

https://www.youtube.com/watch?v=hkGAqk-TXw8&feature=youtu.be

3 years ago I read thishttp://www.nature.com/news/2011/110929/full/news.2011.564.html I think MIT has a jump here