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Posted: 19-04-2009 18:49 Post subject:

Wait I thought we have been through this before? Water is a worse greenhouse gas than carbon dioxide because it retains more solar heat. So if it isn't a self contained model, which hasn't been invented yet, we will be heating things up. Not to mention the large scale droughts and water shortages in major population centers already. Also wouldn't it be icing up the roads in cold climates?

Posted: 19-04-2009 18:54 Post subject:

Hydrogen is the most common substance in the universe, so there's plenty of it on Earth. But it is largely tied up by chemical combination with other elements, and the most common compound is water. (Any gaseous Hydrogen would gradually drift to the top of the atmosphere and be lost into space.)

It can be freed from water by electolysis using any form of electricity, generated by (preferably) non-fossil fuel. There are several forms of electrical energy which do not use fossil fuel: Solar energy, hydroelectric and wind power (these two are in fact ultimately driven by solar energy), and nuclear energy. (When we achieve usable fusion, this will be as clean as the other three sources.)

So hydrogen fuel is the cleanest we know of. It's also hugely abundant in the oceans, and returns to water after use. Nice!

Posted: 19-04-2009 19:01 Post subject:

Posted: 19-04-2009 19:23 Post subject:

We have 625 million** cars on this planet. You don't think all of them releasing a worse greenhouse gas won't have an effect?

Also I live about a thousand miles from an ocean..... Razz

**edit I overshot the real number by a ton. Very Happy

**

Posted: 19-04-2009 23:01 Post subject:

Posted: 20-04-2009 03:25 Post subject:

Like I said before. Putting a ton more "worse" greenhouse gases in the atmosphere is not an improvement.

Posted: 20-04-2009 09:05 Post subject:

Posted: 20-04-2009 11:01 Post subject:

Rynner is right.
You wouldn't be adding any more water vapour to the atmosphere than there is now.

To produce the hydrogen from water, you wouldn't need to burn fossil fuels - you could use a combination of renewable energy such as wind and solar, and nuclear power plants.

Hence, no more greenhouse gases.

Posted: 20-04-2009 23:47 Post subject:

You still have to build the cars which makes greenhouse gases. Razz

My whole deal is that a lot of water will have to be taken from deep wells. Then that water is used and evaporates and goes into the atmosphere. They say that the problem with wells is it takes that water a long time to cycle down to where it had been for years. That is water that was not in the atmosphere it was buried. With all this non surface water in the atmosphere will cause more rain and flooding. Plus, we will have water on our roads all the time that will cause traffic deaths to go up.

Sorry I'm being difficult. I'm just curious about how things will work. Very Happy

Posted: 21-04-2009 00:11 Post subject:

Posted: 16-05-2009 19:44 Post subject:

Cut to the chase.

How viable is it?

And is it as sexy as a Tesla??

Posted: 17-05-2009 10:46 Post subject:

Posted: 20-05-2009 23:28 Post subject: There's No Hydrogen Fuel

Just to clarify:

There is no hydrogen fuel. All the hydrogen found in nature on earth is bound to other atoms in molecular form, usually bound to oxygen (in the form of water) and bound to carbon (in the form of hydrocarbon fuels), or bound to nitrogen (such as with ammonia), etc.

The derivation of energy from hydrogen, used as a "fuel", usually requires that the hydrogen be formed in its most reactive state, such as H2 (i.e. gaseous hydrogen.) Hydrogen is not naturally found in this reactive state on earth, because it so easily reacts and combines with other atoms in molecular form. Therefore, hydrogen fuel has to be manufactured.

The manufacture of H2 fuel from native forms of bound hydrogen is a less than perfect process (according to the laws of thermodynamics); therefore it is required another form of energy, in greater quantity than that desired to be extracted from the H2 fuel. Most processes use electricity as the energy source to convert native bound versions of hydrogen into reactive H2 hydrogen fuel.

This implies that hydrogen is not a fuel or energy source, but rather an energy transportation and storage medium. The energy being stored and transported is that net energy required to manufacture the H2 fuel (conversion from bound state in nature to highly reactive fuel state,) usually electrical in nature; which implies that the energy source to power the hydrogen economy will be an electrical grid powered by (most likely) nuclear, hydro-electric, wind, coal, natural gas, fuel oil and solar.

It should also be mentioned that as an energy transportation and storage medium hydrogen is notoriously inefficient and peculiarly difficult to store safely. Its energy density is notably less than gasoline and diesel fuels, for instance. Additionally, cryogenic methods of storage are peculiarly difficult and trouble-prone, requiring a level of sophistication, engineering and monitoring out of proportion to its purported advantages. Hydrogen airborne concentration monitoring, anti-static delivery systems and the hazards of cryogenic materials, due to their low temperature (material embrittlement, etc) are engineering challenges that have been overcome within industry and space programs only after the expenditure of much money. The technology to handle hydrogen fuel safely is solved, the remaining problem is that the private individual cannot afford the equipment and monitoring systems required to make the system as safe as vaporous liquid fuels used today.

Sorry to put a damper on all the pro-hydrogen enthusiasm, but as a complete system a hydrogen fuel economy doesn't solve many problems, merely exchanges the location within the system where the problems are located; and the efficiency of a hydrogen economy is lower than the present gasoline and diesel economy. Remember: the hydrogen economy isn't powered by hydrogen; it's powered by present sources of energy. The more conversions of energy from one form to another, the less efficient the overall energy system from source to end-use. And the more direct the energy connection from source to end-use, the more efficient. Our present system of extracting gasoline and diesel fuels from petroleum is actually more efficient than the purported hydrogen economy, because there are less energy conversion processes to convert petroleum to mechanical energy in a vehicle's wheels via liquid petroleum fuels as an intermediary than using H2 as the intermediary.

~Joe

Posted: 21-05-2009 00:03 Post subject: