If not stored and not piped properly, yes. 

But Japan is big on safety and so they've built the proper cylinders (like a gas tank) with the tanks to withstand the high pressure.

And they also use proper piping that can withstand the cold temperatures of the hydrogen without the cracking which causes seeping of the hydrogen and that's where most of the explosions occur when they try to use standard gas piping to pump hydrogen through.

The same is true for the hydrogen gas stations tanks and equipment to pump the hydrogen into the vehicles as well. They're just as safe as a gas car or bus and safer than an EV!

FWIW

People don’t even know what car to buy next, as there is a lot of uncertainty with EVs.

If you're not sure what to buy next, go for a hybrid.

I've owned one since 2016 and have absolutely no regrets at buying it whatsoever.

It reduced the amount of gas my previous gas only car used and improved Miles Per Gallon quite a bit.

As it's hybrid, you don't need to charge it with electricity because it charges itself. 

You don't have any of the EV drawbacks and it's a lot cheaper while reducing the gas you use which is eco-friendly!

Hydrogen refill stations are far and few in between and well, EVs, just aren't all what they were made out to be!

FWIW

If hydrogen infrastructure really takes off, in room temperature gaseous form, it has half the density of helium, and thus is a little bit more effective balloon / dirigible / gas bag lifting gas.

If you get some of the really thin aluminized Mylar material and form it where you get a sphere about 1 meter in diameter, fully and properly sealed, then inflate it to about 1/4 of its fully inflated volume, it will lift a surprisingly heavy payload and carry it to where the air pressure outside lets the hydrogen expand to the full size of the sphere, for 1/4 full at sea level will completely inflate at roughly 30,000 feet.

Modern miniaturized electronics and satellite communications hardware can let it stay aloft long enough to literally circumnavigate the globe in somewhere around 2 to 3 weeks on average. If it catches the jet stream properly, under the right conditions it could circumnavigate in about 8 to 10 days.

Because the Mylar doesn't stretch like the latex rubber a weather balloon is made from, it hits the altitude where a lift equilibrium is reached, then the Mylar just holds some excess internal pressure and tends to follow that pressure altitude, because the mass and density "locks" at the fully inflated volume.

It will stay aloft either until a few weeks of ultraviolet light breaks down the plastic and causes a leak, or until some pre-programmed device aboard intentionally ruptures the "balloon" to bring it down, or until the Russians or the North Koreans detect it on radar and decide to waste a surface to air missile on it.

How do I know? I've personally tracked a few of the things. One of my radio devices monitors the usual telemetry frequencies these things are on, which also happens to be the same frequency we use to keep track of spotters during a severe weather Skywarn activation, and it uses the same protocol.

So the Kenwood D-710 will happily decode packets these transmit. And at 30,000 feet, if you're in a rural area and cities are well over the radio horizon, you can easily pick the signal up if it passes within about 250 miles or so. Typically they only transmit with about 2 watts of power, and use a very lightweight solar panel for power. It does a lot of sleep / wake power conservation, and generally they go silent at night. So it's fascinating to track them from when the beacon wakes up in the morning, until it stops at night, then plot the actual ground track on one's favorite mapping program.

But you can certainly launch unauthorized high altitude devices with about 15 to 20 cubic feet of hydrogen in a sufficiently lightweight and gas-tight enclosure.

About 5 or 6 trash bags of 55 gallon drum size, will displace enough air to lift a large railroad flare. Tie the flare to the end of a string about 50 feet long which has been pre-moistened with diesel oil. Inflate the bags on a very dead calm night, let them rise 50 feet overhead, then light the flare and release the whole thing.

It will quickly rise to about 10,000 feet and beyond. If you have a 20 minute flare, you can easily see its red actinic light in the dark, and there might even be people report seeing a UFO.

When the flare burns nearly completely out, it will also ignite the string. The flame will quickly go up the string and burn through the gas bags, leaving only tiny flecks of harmless debris that is fully cold and burned out long before anything can reach the ground.

If it's dead calm on the ground but there's significant winds aloft, the thing can easily travel 20 or 30 miles horizontally before it self-destructs, and you can use a telescope to track it.

Now if you inflate about 48 weather balloons tied to a lawn chair with hydrogen, you could even get famous.

Another useful thing you can do on New Year's Eve if you have, say, 50 to 100 cubic feet of hydrogen to play around with and a big enough balloon and a string of 4,000 firecrackers...

Start inflating it at about 11:45 PM on December 31st, if the wind is nearly zero, as a little wind makes it very hard to control.

Tie a big huge string of firecrackers to the end of the string, which should again be about 50 feet below the gas envelopes.

Be sure that it has positive buoyancy and able to lift the entire firecracker string off the ground, and have about 150 grams or so of residual upward lift, ideally closer to half a kilo (need a bigger balloon for more lift, and it takes a lot more hydrogen).

At 11:59:59, light the fuse on the firecracker string and release it to rise into the night sky.

If the rate of climb is something decent, it should have reached a couple hundred feet by the time the first firecrackers start to detonate, and it should be climbing at around 500 feet per minute at that point.

As the large firecracker string continues to be consumed, the weight drops off quickly which will cause the rate of climb to accelerate dramatically, until it is going maybe 1,500 to 2,000 feet per minute or really quick, as the last of the firecrackers detonate. With a string of 4,000 firecrackers, and a detonation rate of about 10 firecrackers per second, it takes 400 seconds, or 6 minutes, 40 seconds, for the whole string to finally be consumed.

Average rate of climb by integrating the area under the curve should be somewhere between 700 and 1000 fpm. So there will be this ongoing barrage of firecracker explosions climbing rapidly into the night sky that goes on for over 6 minutes.

The last of the debris may take 2 or 3 hours to flutter to the ground.

And you've gotten explosions to go off at altitudes well beyond the most powerful aerial fireworks, even the big class B mortars with massive lifting charges.

$1,661.87 in cats (ROCKETMAN_S) said...

It will quickly rise to about 10,000 feet and beyond. If you have a 20 minute flare, you can easily see its red actinic light in the dark, and there might even be people report seeing a UFO.

ROFLMAO...

Yep, I can just see the news reports about a UFO now! (* CHUCKLE *)

FWIW

LOL...

NORAD will be all over that and probably scramble a few fighter jets to go for a closer look... not to mention all the airlines that will call in a large burst in the air for those aircraft that can see it.

At that height, it should be visible for several hundred miles!

FWIW

Are they still making hybrids? I haven’t car shopped in a while. I wouldn’t even know which model to look at.  

Surprisingly, no one really noticed. Or if they did, there were no reports that ever became public and no one knocked on doors asking around either. Not even the one that was launched in spite late on the night of September 11, 2001 when there would be nothing else in the sky at all.

Nothing scrambled, not even the sound of crickets.

But a hydrogen combustion really doesn't emit a lot of light like a strobe unless you've deliberately mixed in some oxygen, and from a fairly high altitude, it's very difficult to really pin down the source of a loud explosion.

Since the total mass of the entire thing was under a kilogram, there's not much debris to recover, and the plastic bags holding the hydrogen, while somewhat large, do not paint much of a radar cross section.

The only way to make the thing show up is if you make a retro-reflector. It's easy to do. You use some balsa wood sticks for support, and you use 6 sheets of aluminum foil about a foot square (300 mm). They all meet at the center and protrude at right angles. This just dangles below the payload like a disco ball.

The 3 right angle planes of aluminum will reflect a radar beam directly back to its source, the exact opposite of a stealth geometry, and if carefully constructed and precisely aligned, it can reflect an echo almost as bright as an A380 jetliner.

But, a military radar would quickly decide that its very low speed is probably some sort of wind-driven debris, and an air traffic control radar is specifically programmed to ignore such "clutter".

If there is a little bit of a weather inversion, also, radar will be bent back into the ground and pick up stationary or near-stationary objects which will appear to be slow moving and airborne.

In fact, in the advanced Skywarn course on radar interpretation, we saw quite a few examples of this kind of phenomena, including food wrappers (aluminized paper carried aloft by the wind) and the distinctive Doppler signature of windmills about 80 miles away normally below the radar beam but bent into the farm by atmospheric refraction from the weather inversion.

Some day it would be interesting to launch an unauthorized balloon about 40 miles from the weather office, while there is an active storm chase going on, dangling a retroreflector, and being the only one who knows it's there, see if it shows up as a bright pixel on base reflectivity.

Naw, they won't see it. Hydrogen burns with a nearly invisible flame, and at medium to high altitude, if you were staring at it and blinked, you would completely miss it.

The flare looked like a bright red star, from about 6,000  feet below and a couple of miles horizontal (winds aloft picked up as it rose), not much brighter than Betelgeuse, and closer to the deeper red of Antares.

You could tell when it finally burned through to the string because the flare got slightly brighter and then you could visibly see it start to fall, but it went out before it got even 1/4 of the way to the ground - it was still well above the horizon when it went dark.

The actual balloons going up in flame was a much more subtle phenomena. A little wisp of orange from the burning plastic, really the hot particles of soot, and what looked like a hint of blue that was diffused. Raleigh scattering would probably make even a hydrogen - oxygen detonation high in the air at night look like just a very brief slight brightening of the night sky.

Because sound crawls along at only 1,100 feet per second, it probably would arrive so late compared to the flash that it would be mistaken for distant thunder. But a hydrogen explosion in the air does NOT resemble lightning at all.

And I was very specifically looking for it - with binoculars - when it finally went off. The visible effect was - meh.

But it didn't go boom. It went whoof. It was nothing at all like the Hindenberg. Because the Hindenberg's nitrate based fabric dope is what really made the spectacular fire. The hydrogen rose fast as it ignited, so that combustion went straight up, far above the airship, passengers, crew, and people on the ground. The burning fabric and dope and of course the falling structure as it lost all of its lift, is what caused the injuries and fatalities.