Talk:Hydrogen car

From Silent Revolution

Just nitpicking, but combustion efficiency in ICEs is upwards of 95%. A lot of the loss is in harnessing the energy from said combustion – most of it’s wasted as heat. I don’t disagree with your 20% figure for overall efficiency. That sounds about right. 24.202.243.17 18:32, 22 January 2008 (CST)

I'll clarify my wording. The percentage of fuel burned is very high (over 95%), but the efficiency with which it is turned to energy (thanks to Carnot's law) is low (30-35%), and then energy has to be expended to keep the engine running (much of it to dispose of waste heat), leading ultimately to around 20% efficiency. -- Rei 14:19, 28 January 2008 (CST)

RV reasons:

"Although 95% of the hydrogen today comes from natural gas, that electricity could wind" -- 1) This is already covered just a few paragraphs later, and 2) I don't think any of the hydrogen proponents seriously advocate continuing this paradigm.

"although this isn't really a fair comparison with the above because these gasoline efficiency numbers do not account for "well to wheels" like the other efficiency numbers above." Yes, they do. That's what "overall system efficiency" means. Check the reference.

"Although the hydrogen car will be able to go more than twice the range of the electric vehicle and fill in minutes instead of recharging in hours. " -- Thoroughly inaccurate and thoroughly addressed later.

"Hdyrogen cars also don't have the regular costly disposal or recycling of large car batteries which electric vehicles would have" -- Once again, thoroughly inaccurate and thoroughly addressed.

"However, while this is true in a laboratory setting with no air movement, it is impractically hard to recreate in a real-world setting." -- Complete nonsense; hydrogen ignition energy doesn't care whether it's in a lab or pooling under your roof.

"major leaks with no air movement." -- Once again, unreferenced nonsense. Hydrogen pools from *any* leak in an enclosed space.

"One way that makes hydrogen much more safe than gasoline is the fact that gasoline will pool given a leak, while hydrogen, will rise up and away from the vehicle to escape. Some people think that if there were then a delayed ignition source, hydrogen could be ignited, but this is highly unlikely. For a real experiment, see this link to see how an ignited leak from a gasoline car fared against a purposely ignited leak from a hydrogen car. The gasoline's tendency to pool on the ground caused secondary fires and a much more dangerous situation than the hydrogen car whose fire was out before emergency crews would have even been contacted.[1]" -- Your reference does not claim what you stated it does, and you provide absolutely nothing to back up the (rather silly) notion that delayed ignition sources are somehow common and ignition sources from the accident itself are rare.

"One final safety note: proponents of hydrogen sometimes still cite the theory supported by scores of scientist and proposed by Addison Bain that hydrogen wasn't the cause of the Hindenburg disaster. This theory [2]." -- You just deleted two peer-reviewed papers that flatly (and thoroughly, I might add) contradicted the theory, and you link "hydrogenus.com" to replace them with text that doesn't even address the refutation.

Sorry, but these changes are simply unacceptable. -- 129.255.93.182 14:22, 18 February 2008 (CST)