[Borek]

It took Mankind a few hundred years to emit enough CO2 to cause global warming.

How many more hundred years will we need to achieve global precipitation?

I know this argument, but I don't think it applies here. There is not enough oil left to produce enough gas so that exhaust water will become substantial participant in precipitation.

Also note that we are talking about completely different processes (CO₂ assimilation and water precipitation). One is biological, second is pure physics. I have no idea about exact numbers but if someone feels like checking - my bet is that increase of the average annual Earth temperature by 0.1 deg C means higher increase in the amount of water in the air (water from natural sources) than we can produce burning all oil we know off. Water from exhaust is negligible in this system.

[Donaldson Tan]

How about we just all use straight electricity. Can you say, "Pluggable car."

There are so many proposals on what the future technology is. What is lacking is the bridge to the future.

[billnotgatez]

How about we just all use straight electricity. Can you say, "Pluggable car."
...

Where does the electricity come from that you "Plug" into?

For this exercise assume that Fusion Nuclear will still be in the experimental stage for 100 years and you do not have di-lythyum crystals (as in Star Trek).

[enahs]

I stand corrected ever so slightly.

Carbon dioxide gas is limited by the amount of carbon on the earth and water vapor is limited by approximately 100 % relative humidity. Water vapor can attain less concentration than the carbon dioxide gas even if you imported more hydrogen and carbon from the universe.

Aww come on. You had me quoted about the finite number of carbon and hydrogen. You where supposed to mention that finite quantity is oxygen, as they share oxygen in common.

[billnotgatez]

You know I thought about that and then said “Naaw he won’t catch me on that”. I am just tooo slow sometimes.

Aww come on. You had me quoted about the finite number of carbon and hydrogen. You where supposed to mention that finite quantity is oxygen, as they share oxygen in common.

[billnotgatez]

Is anyone going to take up the gauntlet and make suggestions for the plug in source of energy?

I was just listening to a radio program that said that there is not enough crops to make bio-energy in the USA. Well at least not enough ethanol could be made. Would methanol be better?

[Yggdrasil]

I was just listening to a radio program that said that there is not enough crops to make bio-energy in the USA. Well at least not enough ethanol could be made. Would methanol be better?

Using current technologies which make ethanol from corn, the US would not have the capability to fuel more than ~30% of its vehicles with ethanol.  The ability to make ethanol from cellulose could greatly expand our capabilities to produce ethanol but the technology is still in development and the costs associated with creating cellulosic ethanol have not been well established.

Also, I don't know how methanol differs from ethanol as a fuel and in its production.  Does anyone have any information on this?

[billnotgatez]

http://www.chemicalforums.com/index.php?op=Articles;article=26
The above has a discussion of bio-fuels which I am rereading.

http://www.methanol.org/
Of course the above comes from a biased group but may have useful information.

When spouting out opinions one has to do ones research and try to understand if there is any bias.

For instance Ralph Nader would be biased, he may also be correct. Notice the operative word is may.

[constant thinker]

I think it was Borek or maybe geodome that had calculated how much land it would take to produce enough fuel to satisfy the U.S.'s demand for energy.

Does anyone else remember this because I can't find the topic/post.

[billnotgatez]

Fill your car up with aluminum?
http://news.yahoo.com/s/nm/20070518/us_nm/fuel_hydrogen_dc
why did we not know about this before

[Donaldson Tan]

Let's analyse how Aluminium would work out as hydrogen for transport:

Assumptions
Density of Gasoline = 737.22 kg.m^-3 = 2.7907 kg/gallon
Efficiency of Internal Combustion Engine (ICE) = 35%
Efficiency of H₂ Fuel Cell (FC) = 60%
 

	Substance		Energy Density
1.	Hydrogen Gas		120 MJ/kg
2.	Ethanol		23.4 MJ/kg
3.	Gasoline		45 MJ/kg
4.	Diesel		45 MJ/kg
	Vehicle Type		Petrol Mileage		ICE Consumption		FC Consumption
1.	Passenger Car		22.4 Miles/Gallon		2.769 kJ/Mile		1.615 kJ/Mile
2.	Vans, Pickups, SUVs		16.2 Miles/Gallon		3.828 kJ/Mile		2.233 kJ/Mile
3.	Trucks		06.7 Miles/Gallon		9.259 kJ/Mile		5.402 kJ/Mile
4.	All Vehicles		17.1 Miles/Gallon		3.627 kJ/Mile		2.116 kJ/Mile
	On a basis of 1000 miles
	Vehicle Type		H2 Required		H2O Required		Al Required		Gasoline Required
1.	Passenger Car		0.0135 kg		0.1215 kg		0.1214 kg		124.6 kg
2.	Vans, Pickups, SUVs		0.0186 kg		0.1674 kg		0.1673 kg		172.3 kg
3.	Trucks		0.0450 kg		0.4050 kg		0.4047 kg		416.5 kg
4.	All Vehicles		0.0176 kg		0.1584 kg		0.1583 kg		163.2 kg

There is storage space available for 158g of water and 158g of Aluminium. Their total space storage would be so much less than the space required for 163.2 kg of gasoline (58 gallons).

Price of Aluminium on London Metal Exchange (US$/25tons)

Based on the price peak (US$3000 / 25 tons) in the above chart, the price of aluminium for topping up an average vehicle is $0.02. However, if one to take in account of the effect of supply and demand of Aluminium for transport, I would not be surprised that Aluminium price would grow to at least 50-70X its current price. Taking in account of logistics, tax and profit, one might expect the the price increment of $100-200/kg. A more realistic price for Aluminium at "petrol" kioks would be $2-4 per 1000 miles, compared to $1.50/gallon for petrol.
 
But there are definitely challenges in implementing this technology.
1. The availability of Gallium to store Aluminium in the form of a liquid alloy
2. Will the liquid alloy freeze in winter?
3. Controlling hydrogen production rate at the micro-gram level in a car
4. Separating Al₂O₃ from the Gallium alloy
5. Can Aluminium be regenerated via electrolysis in liquid Gallium?


Reference:
1. Energy Density Data: http://hypertextbook.com/facts/2003/
2. Transport Consumption (USA, 2004): http://www.eia.doe.gov/emeu/aer/txt/ptb0208.html

[constant thinker]

Nice tables geodome.

This is something to keep an eye out for. It'll be interesting to see if this technology winds up working on a commercial scale.

[Sam (NG)]

The aforementioned cellulose-->ethanol catalyst: http://www.rsc.org/chemistryworld/News/2006/July/13070601.asp

Requires Hydrogen gas, hmm, wonder if it would be preferred just to use hydrogen as a fuel.

I have the possibility of joining a research group on NiFe hydrogenase scalability next academic year. (Water to hydrogen and oxygen).  Worth joining?

[Woofuls]

Note: I did not stick numbers anywhere, I'm sure that the CO₂ is worse than water vapor as a green house gas.

It depends what you mean by worse... Water vapor absorbs thermal radiation, from the sun, BETTER than carbon dioxide.

Anyway, about energy in general...

What I dislike seeing is how people push other individuals toward ONE solution: "IT'S NUCLEAR ALL THE WAY BABY." "Screw Chernobyl, how about some corn, every one likes corn because it sounds a lot like porn," and etc.

Finding just one solution doesn't happen all that much in math. In some systems, there are infinite ways to express the solution. So, why can't our energy solution be made up by a variety of "equations"? It doesn't all need be just ethanol or methanol or geothermal or fission... that is, until fusion matures. ;-)

I think we should keep plucking away (RESEARCH!!) on many different projects and try them out in the real world. Every system will have its cons and pros. It seems to me, that by utilizing many different technologies you will get a smaller amount of the cons (i.e. at the least the cons will be spread out and seem far less grisly and manageable rather than having them clumped together in a massive pile) while getting all the pros. It just seems logical until research finds better stuff.

My $0.23

[Donaldson Tan]

It is easy to have a variety of fuel for electricity generation but it wouldn't be the case for transport, unless we switch to electric vehicles.