Hydrogen cars: A new approach

Okay so everyone's on about hydrogen power, but it is not without it's impracticallities.

"Here's the tank of lies"

No, you can't make a car run on water by electrolysis with the battery of the car that's powered by the engine that's powered by the hydrogen that's powered by... No such thing as free lunch. Stop wasting time and money please.

Toyota Mirai - Courtesy of Toyota

Currently, the Toyota Mirai is pretty much the only mass-market hydrogen car. It's extremely expensive because they opted for an electrical drive system, powered by a fuel cell, which converts hydrogen and oxygen (from the air)
directly into voltage. It has a reasonable 300-mile or so range, but the hydrogen is stored in carbon fiber tanks at 10,000 psi. In the event of a major accident, this would definitely be problematic, and the fueling system isn't really a walk in the park either.

Hydrogen can be burnt in conventional combustion engines, with practically no modification. This is appealing to many automobile manufacturers because they just don't "like" changing anything, ever. It's not as efficient as the Mirai's fuel cell/electric hybrid system, but definitely cheaper.

The clear advantage to hydrogen fuel is that it's renewable. The ONLY resources needed to create it are any source of water, clean or otherwise, and electricity. Alternately, it can be steam-cracked from natural gas, which, in the event of fossil fuel's eminent demise, can be derived of feces from our artificially inflated subsidized corn driven murderous meat industry.

A REAL hydrogen electrolysis rig - http://www.extremetech.com

Either way, a fuel shortage is practically impossible, as demand rises, technology can rise to the challenge and make the process more efficient, eventually reaching an equilibrium. Hydropower also stands out, because it's cheap, easy, and inherently has water nearby. If a significant quantity of our automotive fuel came from solar, we would eventually actually cool down the earth as well, by converting sun heat into our cars moving around instead of warming stuff up.

BUT HOLD ON, these 10,000 PSI storage tanks are conceptually PRETTY FAR OUT, dangerous, and also expensive. IF ONLY there were a more dense way to store hydrogen! Wait, what about water?
Here comes my plan: Water, at no pressure, will be used to store hydrogen on-board the vehicle, and a completely unrelated compound will be used as energy storage, to extract the valuable gas from the water. I recommend: Calcium.

Pure Metallic Calcium

Calcium is generally thought of as some white crunchy garbage, or milk, or bones. In actuality, these are all calcium compounds, and the pure element is a chemically reactive metal, which happens to catalyze the separation of water's elements, becoming calcium hydroxide, and leaving a spare hydrogen for your trouble. Time for math:

Let's say your (inexplicably large) car has a 20 gallon tank (weighing 57kg, or 126 pounds). The energy content of that much gasoline (how much actually potential WORK there is, regardless of how heavy/large/whatever) is just about 2,600 MILLION joules. A joule is just a nice little packet of energy used in chemistry and physics, it's actual definition matters little right now, as I'm just using it as an intermediary.

To get that much energy from hydrogen gas, you would need about 18.5 kilograms of hydrogen. In gaseous form, uncompressed, this quantity of gas would be enormous, about 200 cubic meters, or over 50,000 gallons. However, water, by weight, is about 12% hydrogen, so the same gas stored in water (and extracted by calcium) would be about 88 gallons. BUT WAIT! You can recycle your water, because after your engine burns it, it's exactly the same as it started. Therefor you'd likely only need a few gallons of water at any given time.

Now, the calcium to extract all the hydrogen you'd need for your 2.6 GIGAJOULE energy needs would have to weigh.... 1,630 pounds, or about 4 full-sized drums of the stuff.

Now hold up, recent research indicates the Mirai, Toyota's hydrogen car, only has a 5kg tank of hydrogen. If that's enough for 300 miles, then we could get by with only a barrel and a half!

That's still a no, then. Okay.

Viability of a personal air conditioning coat

I'm wicked hot and it's cramping my stay-clean-with-only-one-shower-a-week game, so time to complain and make up solutions involving too much tech. AIR CONDITIONING COATS!

Okay first off: The human body is, on average, about 65% water for a typical adult male. Less for women because they've got fat everywhere, less for dehydrated sons of guns like myself, but this has to be marketable to normal people. Let's say our clientele is 150 pound dudes, at 65% water, that's 97.5 pounds of water, or 44.25 kilos, thus, 44.25 liters.

Humans are, generally speaking, 37 degrees C (No I'm not converting that to F, deal with it United States), so I'm going to estimate how much energy it would take to lower all of the water in our bodies by, say, one degree. Math o'clock.

Water takes on average about 4.2 joules to heat one gram (or CC) of it by one degree, so I'm going to assume we're going to use about that much energy to cool it. For our 44,250 grams of water, that'll be 186,000 joules. This is already looking super inviable, but let's carry on.

A joule can be expressed as a watt second, so 1 volt at 1 amp for 1 second, that's a joule of energy. Assuming we want to be cooled down in, say, 20 minutes, that's 1200 seconds, so we'd need... 155 watts. Not half bad. An 18 cubic foot refrigerator generally requires about twice that, while running, but they don't run all the time, because they're super insulated and only need to run when it gets too warm.

Now, in actuality, much more energy will be needed because refrigeration isn't very efficient. For every watt of cooling, you have to spend several more on motor friction, heat loss, other stuff. Since this is going to be a magic jacket, I'm going to presume Peltier cooling, which is a solid-state plate which has the advantage of lasting a very long time, having no moving parts, and no hazardous refrigerants. They are a miserable 10% efficient, so, the power we need is actually ten times what was listed.

Holy crap, that's 1,550 watts. This is intolerable. Where are we going to get that kind of energy? This is just ridiculous. If we use 24 volts, that's like fifty amps. The wire alone for that kind of current would weigh a ton, not to mention that most cheap peltiers are only 60w, so we'd need 26 of them.

Batteries: I went on an RC plane website and found a LiFePo4 battery that could handle 8.4 amp hours at 6.6 volts. Say we use four of them for the voltage requirements, that would still only run it for 20 minutes. Total weight of the project would have to be about 8 pounds, and there'd be losses for any kind of circulation pump, jesus. What a terrible idea.