Definatey wont see this on a jet ski anytime soon.
When electronics became integrated to motor vehicles,
a large percentge of motor mechanics left the buisness.
Nowdays a lot all themselves technicians, What willthe next generation call thelvebA

Does anyone else besides me see this as horribly inefficient? How about terribly expensive? Anyone?

To the hydrogen developers, efficiency is not a development concern. In fact, they can ask for more federal subsidies when the process is less efficient at the start. At the same time, natural gas prices can be boosted to very profitable levels for them. This is a win/win scenario for them.

"The system that will be integrated into the HICE Silverado consists of a 10 kg liquid hydrogen, super-insulated tank with a nominal operating pressure of 550 kPa (80 psia), an active-cooling loop around the tank, a low-pressure, drop cooling loop helium circulation blower, and the Sierra Lobo two-stage pulse tube cryocooler driven by a long-life linear compressor. The active-cooling loop is connected to the pulse tube cryocooler at the 2nd stage cold heat exchanger, which operates at 20 K (-253°C)."

OR, and I know this is radical idea, but you could also have a solid state battery that stores electricity that has no moving parts at all, nor any parts at 20K.

Ha ha, they won't get fired. The federal appointees from the oil industry will give them full funding. You guys are doing a "hecka job", etc.

No-vent LH2 system makes little sense, even for the military, when it consumes 600w of power all the time. In the field, it's no good, since where does the electricity come from to power the refrigerator? At base or camp, it's not of much use, since one can always fill-up the LH2 tank prior to use and save the base or camp electrical grid from additional electrical load.

Just use a regular LH2 tank and feed the vented H2 to the engine to produce electricity to feed to the grid where the vehicle is parked, resulting in no wasted energy. Far more practical in the field would be a recently featured 5000psi LH2 tank that can keep a full tank for 6 days without venting, and it can keep 1/3 of maximum H2 capacity for an indefinite period of time.

However, small-size H2 liquifiers like this would be valuable for a military camp or base to produce and liquifying its own LH2 fuel in the field from wind or solar electricity...hence greatly simplifying the logistic of having to transport flammable fuel in convoys that would be very dangerous in an ambush. For a much larger LH2 reservoir than this 10 kg tank, like a 1,000-kg or 10,000-kg tank, the surface area to volume will be much lower, hence LH2 can be stored using far less power per unit of mass than in this 10-kg tank, justifying the logistic of LH2 in the battlefield.

Imagine Gen. Rommel in WWII having this kind of modern-day LH2 fuel supply system...

For the military it makes perfect sense as it allows them to put a uav aloft with a 500 kg tank of fuel and get 19 MEGWATT HOURS out of it.. minus a little MINOR power draw to keep it all cool. Thats moew then enough fuel to power a laser cannon and fuel the plane and electronics.

it makes sense for an UAV to stay parked at 70,000 ft, with that 500kg tank and solar cells.. also the cooler should be more effective at that altitude since it is colder.

The main European promoter of hydrogen fuel cells was a scientist who remembered how to do arithmetic and could not work out any way to have hydrogen fuel cells work in cars. So he is promoting something else. Electric cars are far more efficient; ZEBRA batteries need to be kept hot, but they require far less power and only simple resistive heating, and they will not blow up if power fails. The electrical energy in the TH!NK ZEBRA battery could be used to keep it hot for (26000/2400) more than ten days. This would be more than enough time to get to a plug to recharge and does not consider the heat energy available as well.

Electric cars must all be required to be series hybrids with at least a small emergency charging engine generator, so that they can be filled at any gas-station. Ethanol would be the clean fuel of choice, but the use of gasoline in emergencies should be provided for.

Petroleum companies diverted funds away from one researcher who, thirty years ago, promoted methanol from coal as the future locally produced car fuel.

Liquid hydrogen may well be the best fuel for unmanned military aircraft, as it works very well for rockets, but fuel cells are too heavy. But you will have a machine on the ground that will convert diesel to liquid hydrogen with large energy losses.

It would take less space and be cheaper and easier to run a car engine that sequestered CO2 and H2O than the current fuel cells do.

Modern car diesels already have nearly the efficiency of fuel cells and can be run in a combined cycle for even more efficiency.

There's also another danger using liquid hydrogen: it is EXTREMELY explosive.

Imagine if you're driving a vehicle fuelled from an LH2 tank and you get into an accident--if the LH2 tank even has a very tiny leak it will literally become a powerful bomb.

Am I the only one to notice that the 600W is the nominal power of the cooler, which will probably switch on only if the temperature rises, like a refrigerator. I think it is not true, as some suggest, that it needs a 600W to keep the H2 liquid.

@wintermane:

Whether it makes sense depends on how much boil off you prevent. It is no use adding a 10 kg compressor to prevent a boil off of 5 kg H2.

Have to agree with JT here. We need to get away from this one vehicle fits all paradigm(8 passenger 4WD SUVs, and extended cab pickups come to mind.) Small all-electric cars (even with limited range) would suit most people's daily commuting needs. PHEV's, HEVs and diesels could provide for the rest of our needs.

A LH2 tank is not explosive at all !.
the boiling of liquid H2 is an ENDOTHERMIC process, thus it will certainly not be an explosive event. very fast, it will freeze its surroundings, and then the rest becomes vapor rather slowly. The gaseous H2 off course is flamable, but not more than natural gas. BUT, since gaseous H2 is very light, it will rise to the stratosphere very quickly, making a real big explosion relatively unprobable, compared to natural gas, which is relative heavy. A big leak of natural gas can lead to very very very big explosions if there is no wind and the detonation occurs hours after the leak is created. with hydrogen, there would never be a big build-up to cause such explosions.
A natural gas leak will crawl over the surface until it encounters a spark...boom
A hydrogen gas leak will immediately go to the skies, making a detonation unprobable.