Hydrogen turboalternator

[john]

Ok... Si im now convinced by the numbers

100mph
100mile range

similar performance, similar price to a traditional bike.

In my head, im trying to resolve the final issues I and many will have.
"what if you run out of power" ?

After looking at many ways to portably top up the batteries im starting to think - A Tiny hydrogen turboalternator top up generator ?

do they exist ?

[Phantom]

Welcome to the forum. When you get used to riding an EV motorcycle, assuming that you have not, you become more aware of pre-planning trips. There is no doubt that EV ranges will increase over time due to new technology, but I think it is good to keep thinking about possible range solutions.

Check out the below link which somewhat debunks a pure hydrogen solution, but opens the door for other alternative energy fuels.

http://www.bladonjets.com/

[john]

Hmm... its too big for a bike.... needs to be smaller...

And.... why can't it run off Hydrogen gas ?

On Demand Hydrogen fuel production could surely produce enough to keep a small gas generator spinning for hours.... more so for one the size thats required which would be 1/3rd the size of that.

3 tubes.... (all the size of coke cans)

1) On demand Hydrogen Production unit
2) Gas Turbine
3) Alternator

integrated as a pack (Hydrogen unit replaceable) situated under the battery pack behind the front wheel.

Ford/Jag are experimenting with this concept.... But... minimize it, and include on demand hydrogen generation (instead of hydrogen fuel cell) and you have the perfect emergency range portable power plant.

[Phantom]

I suppose it could, but the site claims that a big hydrogen distribution network is not practical yet.

I hope hydrogen can be used soon as a safe fuel source. I saw a documentary on a hydrogen fuel-cell motorcycle in England.

http://www.webbikeworld.com/motorcycle-news/fuel-cell-motorcycle/

[john]

for a hydrogen only vehicle a hydrogen fuel cell is required.

What im talking about though is a small on demand hydrogen generation unit capable of generating enough electricity to top up the batteries.

So.... Distribution network is already in place.... Distilled water from supermarkets and a pepper pot sized tub of baking soda. but.... the unit would already be full of water in the event you need that emergency charge.



I would suggest something more specialized to the task releasing the hydrogen quicker through a gas turbine = quick charge. Brammo themselves could supply the fuel canisters.... you could keep a couple spare on the bike.

[john]

Something like this....

Jet in the middle..... Charger at one side, water cylinder at the other. (screw top water cylinder)

should be the right size to provide enough hydrogen to the jet for one full charge.

Simply top back up with water once used

Would require some power from the battery... just enough to initiate hydrogen separation and a small gas pump to drive it into the Turbine = lots of thrust for the charger

[FreepZ]

Yeah, the famous "just add water" battery.

What folks don't appear to realize is that the electricity does not come from the water, just like you don't have a nutritious soup that is just made of water. The water might be an important part of the thing, but you can't get more energy by just topping off with more water. The actual energy comes from whatever is in the canister.

The guy in the video was saying that you would need 5 of those canisters to get 1kWh - so there's not a whole lot of energy in there.

But who knows? Perhaps canisters can be developed that have a lot of energy, and that could be the new fuel. Right now, I don't think it's quite ready to do more than keep your laptop running for couple of days during a blackout.

[protomech]

Here's my rudimentary understanding of the proposed hydrogen turboalternator system:

1. Current + ionized H2O flow into Electrolyzer producing H, O2, residue (50-80% efficient wrt H chemical energy)
2. H flow into Gas Turbine producing torque (~40% efficient)
3. Torque to Alternator producing current (~90% efficient)
4. Current into Battery OR Controller into Motor producing torque (~90% efficient)
5. Torque to Wheel producing whee (~95% efficient)

The main problem is the energy you lose in steps 1-3. You get 0.2-0.3 kwh of electrical energy out of the alternator for every 1.0 kwh of electrical energy you put into the electrolyzer (.8 * .4 * .9). Entropy is a bitch.

And where does the electrical energy come from to start the electrolysis process? Under normal conditions*, your main battery pack. You're better off sending the battery's energy directly into the motor.

* you could use power recovered while braking, which is typically much higher than the best batteries can accept. I don't have any idea how much use an electrolysis system could get out of a couple seconds of 40kw .. if you have to buffer it with an ultracapacitor, then again you're better off bleeding that ultracap into the motor controller or back into the battery.

[john]

As I understand it......

It takes a very small electrical charge to separate the H from the 2O

but once separated the H is HIGHLY EXPLOSIVE = more energy than the current required to expose it.

Your not trying to create Energy.... its there for the usage ... just takes a small current to activate it.

Put it this way... are Jaguar/Ford Wrong ?

[protomech]

To the best of my knowledge, no major auto manufacturer has plans for onboard hydrogen generation. Most manufacturers, most notably Honda, GM and Toyota, have hydrogen research projects, but these are mostly fuel cell vehicles with heavily reinforced high pressure hydrogen tanks. The tanks are filled at specialized hydrogen refilling facilities, and left alone will self-discharge in about a week.

Unfortunately, using electrical energy to split water into hydrogen does require a fair bit of energy - more electrical energy than chemical energy, in fact.

One of the best electrolyzers is 83% efficient per Higher heating Value, or 46.8 kwh/kg. Assuming the rest of the electrolysis system is perfectly efficient, you could produce 0.213 kg of H2 chemical energy with the Empulse 10.0 kwh pack.
http://www.nrel.gov/hydrogen/pdfs/36734.pdf (6.2, Energy Efficiency)

Hydrogen is 141.80 MJ/kg (HHV), or 121.00 MJ/kg (Lower Heating Value or LHV). 0.213 kg of H2 has a LHV of 25.8 MJ of chemical energy.
http://en.wikipedia.org/wiki/Heat_of_combustion#Heat_of_combustion_tables

The best microturbine efficiency is around 35% per wiki, using LHV. 25.8 MJ of chemical energy becomes 9.0 MJ of kinetic energy. Combined heat and power plants are somewhat more thermally efficient (60% range), but useful electrical power output is lower.
http://en.wikipedia.org/wiki/Gas_turbine#Microturbines

The best alternator efficiency that I can find is around 70%, which is much lower than I had expected. I suspect alternator/generators sized for vehicle output may be higher efficiency.. let's assume my 90% estimate earlier is possible. Then 9.0 MJ of kinetic energy becomes 8.1 MJ of electrical energy, or 2.2 kwh of electrical energy.
http://www.delcoremy.com/Alternator/Fuel-Efficiency.aspx

Fuel cells (which accept hydrogen and output electricity) replace the microturbine and alternator in the above system. The best fuel cells are around 50-80% efficient, which would produce (at best) 20.6 MJ of electrical energy, or 5.7 kwh of electrical energy.

You lose energy at each conversion step .. to the point where if you have a 10.0 kwh battery pack, you're better off using it to directly drive the motor.

[john]

Great stuff.... you know your onions !

I would still like to see it fail in practice by way of experiment. Im a bit lateral in my approach which leads me off in a new direction.

If not Hydrogen then what ?
http://www.gepower.com/prod_serv/products/tech_docs/en/downloads/GER4601.pdf

I much prefer the idea  of on-board Hydrogen generation than a compressed tank of the stuff.

So.... maybe not worth the effort for a minimal gain to use the battery to juggle out the 'H' So the options for such a system are simply to use a traditional or Bio fuel to power the turbine.

Or..... multi fuel where Bio fuel is used to run the turbine which also supply's some of the generated current to a hydrogen plant whilst also topping up the bikes battery, the resulting Hydrogen fed into the combustion chamber along with the bio fuel boosting the rpm.  ??

Just brainstorming 

[Brammofan]

Hydrogen?  Did someone say hydrogen???!!!

[smg id=257 width=600]

[john]

LOL ...yeah..

some good ideas are born of bad ones though 

I know the bikes are green because you plug them in.... but the more electric vehicles on the road, the bigger the load on the electrical grid and powerplants.

I like the idea of Stirling engines
Maybe a portable Stirling engine to stick in a camp fire every 100miles on a world bike trip ? charging the batteries overnight ? in essence, a wood burning electric bike. That would make some press !

[Vibetrippin]

If you're just looking for something that will let you limp back in after you foolishly exceeded your range limits, why not look at some high efficiency solar panels? The tech is out there that would let you form most of a fairing out of solar film/cells. It's not going to let you ride indefinately without charging but it would let you roll back home at a reduced speed. (after a suitably humbling time sitting on the side of the road with your head hanging in miscalculating shame.)

[HighlanderMWC]

What if you run out of power? Extension cord. You're probably closer to an electrical outlet than a gas station. If you're in a situation where you plan to push the range a gasoline generator towed on a trailer is probably the simplest and more likely to be bulletproof. An AC Inverter would be an avenue to try to use the engine of a car.