...belief in this kind of crap is doing exactly that.

We just spent two trillion bucks on the useless solar and wind junk in the last ten years, with the result that for the first time in recorded history we are now exceeding 3.00 ppm increases in carbon dioxide per year.

The wind and solar industry are entirely and completely dependent on access to dangerous fossil fuels, cannot produce even 5 of the 570 exajoules of energy humanity consumes each year, and all of this thermodynamic ignorance about stupid schemes like hydrogen are making the situation far worse.

So called "renewable energy" hasn't worked, isn't working and won't work.

That's not sarcasm; it's a fact.

Extremely flammable and with a ruptured tank of hydrogen, even a small amount, you have a bomb on wheels. Yeah, I know about the tanks on natural gas vehicles and their supposed burst ratings. But let a fire come in contact with the tank and the heat greatly increases the pressure. I saw one of the water produced hydrogen cutting torch units about 25 years ago. Those things produce only enough hydrogen to keep the flame going. A car can't operate like that with accelerating and slowing down. A storage tank will have to be utilized.

It's mostly the province of people who have never passed an engineering course or a course in thermodynamics.

We have lots of ways to waste energy, and we do waste energy, but very little energy is actually wasted on producing hydrogen, except for captive use.

That shit-for-brains former Governor of California, Arnie Schwartenegger, was driving around in his idiot hydrogen Hummer. How many hydrogen cars are tooling around California today as a result of his enthusiasm?

Due to the relative inefficiency of an internal combustion engine, a “standard” automobile needs to carry much more energy in its tank (in the form of gasoline) than a hydrogen/fuel-cell vehicle. Gasoline powered cars have been known to catch fire on occasion as well.

Here we have intentionally set fires, one of a car with a hydrogen tank, and one one of a car with a gasoline tank.

http://www.40fires.org/Wiki.jsp?page=Hydrogen%20Safety%20-%205.%20Gasoline%20Vs.%20Hydrogen
[center]
[font size=1]Figure 1 - Left: 3 seconds after ignition. Centre: 1 minute after ignition. Right: 1.5 minutes after ignition.[/font][/center]

https://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/30535be.pdf

should have already started putting in the infrastructure. This needed to be fast-tracked; instead, the oil industry wants to make sure we've extracted and burned every last drop of fossil fuel, and then that they own whatever source is next, before we can move forward.

That's a pretty big assumption. We're at like 12% renewable today?

Given that you've produced said renewable energy, forming the hydrogen and then recombining with oxygen in the fuel cells are two independent steps, neither of which is terribly efficient. You wind up throwing most of that energy away.

At least using that renewable energy to charge a battery you can easily use 80-85% of it to move a vehicle (limited mainly by charging efficiency). With fuel cells, we'll be lucky if the two steps (electrolysis and fuel cell operation) ever reach 70% each, guaranteeing the loss of half the energy by the time you take that renewable energy and put it to use.

There will likely be circumstances where that loss does not matter, but since battery EVs already perform well enough to meet the needs of most drivers in daily use, electricity distribution infrastructure actually exists, and the overall process is more efficient, a big push for hydrogen right now would mainly have the effect of supporting and expanding the continued extraction of the fossil hydrocarbons that will remain the chief source of hydrogen for the foreseeable future. Using renewable energy for transportation doesn't have to wait for a less-efficient infrastructure to be created.

I certainly recognized in my post that what the paper you link calls round-trip efficiency won't always be the most important consideration, and that creates some niches for fuel cells.

Also, am I understanding this analysis correctly? What it tells me is that under a certain range of circumstances, for wind specifically (because the energy investment in producing both the turbines and the RHFC systems and associated hydrogen storage is very low), a fuel cell-based storage system could be advantageous. It's not entirely obvious whether those circumstances obtain in most cases or in exceptional cases (I would need to spend more time picking through their analysis than I can devote now to be sure which).

I found one paywalled journal article related to this project and otherwise a bunch of press releases and articles based on them. It is apparently achieved because their not looking at the energy in electricity but thermal energy. In fact, a big part of their pitch is really about the ability to feed hydrogen into natural gas systems at low concentrations, using it to make methane, district heating systems, etc. in addition to doing things like filling hydrogen car fuel tanks. The 86% is an "energy utilization rate" that isn't rigorously defined in any source I've been able to track down.

I don't think that figure describes what happens to the transportation use of renewable energy to produce hydrogen, which was the subject of the OP.

...garage scale bullshit?

Firsts?

How about lasts?

The last time we will ever see carbon dioxide readings below 400 ppm is already in the past, and still we have people paying attention - as if it fucking mattered a whit - about a fucking single megawatt thermodynamic nightmare storage device.

Right now, human energy consumption is at more than 570 exajoules per year. This translates into an average continuous power demand of 18 million watts.

This appalling lack of a sense of scale on the part of the wishful thinking that has caused humanity to invest heavily, and uselessly, on unsustainable junk that has not worked, is not working, and will not work.

This crap was failing at Utsira a decade ago, and still, we have people repeating the experiment endlessly hoping that they'll get a different result.

It's pure idiocy, a crime against the future.

...on the "Watts."

This obviously makes the situation even worse, by a factor of one million.

But I have seen several deploy-able new battery technologies in the last few months.

If batteries can be recharged in the 5-10 minute time frame, and the weight and energy density continue to improve, Hydrogen & fuel cells will have a hard time catching up for this applications.

And there will be billions needed in infrastructure build out for hydrogen.

But Hydrogen is a way for the current HydroCarbon corporations to keep their monopoly power going for a few more decades. If we are still here to worry about it of course.