Fuel cell vehicles

Ideally, what we want in the short term is a fuel cell that can be operated off of propane or gasoline without being poisoned. Folks are working on that.

The efficiency of the internal combustion engine is kind of poor, and it is worse in automobile applications where the engine is throttled down most of the time.

A fuel cell combined with an electric motor gives you high peak power, and good efficiency at low power as well. This means less fuel used and therefore lower emissions.

In the long term, hydrogen distribution may turn out to be a good idea but it's a difficult problem to solve, and there's already so much gasoline distribution infrastructure that it's hard to replace.

--scott

BUT, if the hydrogen is generated in only a few locations, it makes it a LOT easier to scrub the emissions and much simpler to implement new technology.

Also the minor technical problem of fueling the car and carrying tanks with less than the thousands of pounds pressure needed.

George Olah, Nobel prize winning chemist,is touting methanol for fuel cells. Methanol is readily available from coal or natural gas.

Commercial fuel cells are probably not going to be available for at least 10 years.

There are significant indirect costs in producing any energy source. Crude oil has to be pumped, transported great distances, refined and transported again before an automobile can consume it. Hydrocarbon energy figures heavily into converting crude oil in the ground into gasoline in the tank.

Yeah, but the methanol fuel cells still have the carbon disposal problem. I believe some of them do emit CO2. So, it does not eliminate greenhouse gases. Also, making methanol requires a lot of energy. I have been looking for figures on that, but I assume it would be similar to ethanol production, and that process barely breaks even. It takes almost as much energy to make ethanol than what you get back. Depends on the process, some are more efficient than others. Burning biomass for fuel helps reduce petroleum consumption.

True, but you still get out a substantial fraction of the original energy, while you get a lot less with ethanol. And with hydrogen production, you cannot even break even!

The problem is that we've had well over a century of development in doing it with petroleum, and so the processes and procedures are pretty well-known and stable.

This wasn't always the case... used to be kerosene lamps had a bad reputation for exploding before they figured out how to get all of the light gasoline and naptha fractions out of it. But by 1890 or so, it was safe and reliable.

Where we are with hydrogen development and distribution is about where we were with petroleum around 1905, except that we're putting a lot less money into development than we were putting into petroleum in 1905.

--scott

I would like to see the details for a break-even analysis for not only for various sources of hydrogen but crude oil. There are a lot of generalities being passed around but not a whole lot of specifics.

The point is not whether the processes for delivering one energy form or another are stable or not, although those certainly are important issues. The point is that to take crude oil from the ground and transform it intop gasoline inb the tank requires significant amounts of energy usually in the form of other hydrocaron produucts to be consumed along the way. As it is with electricity, hydrogen, vegetable oil, etc.

The only free lunches are those where someone else pays the tab.

You can give the money to R&D, or you can give dividends.

Oh, absolutely. But as long as we have plenty of crude oil to do it with, it doesn't matter.

The problem comes when we don't have available crude oil. Most "alternative energy systems" are not energy sources, but energy distribution systems.

Hydrogen, for instance, is an energy distribution system. You take energy, make electricity, make hydrogen, pipe it around, and burn it or use it in fuel cells to get motive power or more electricity. Efficiency is pretty good. But you need to get the energy in the first place.

Yes, that's the marvelous thing about petroleum. The tab was paid with sunlight, millions of years ago.

--scott

But at least petroleum products still yield a net amount of energy. Hydrogen by electrolysis does not. I don't know about the yield on other methods of making hydrogen- would like to see the numbers. For biofuels the studies I have read does show a net gain (i.e., biofuels ARE a SOURCE of energy) but not as much as petroleum.

Of course, in our modern world we also need to consider the environmental consequences of various strategies to obtain energy.

What exactly is a net amount of energy and how is it measured.

In article , "John S." wrote:

What it is:

The amount of energy available from something after taking into account all energy put into the making of the something. Using "pulled out of thin air" numbers for purposes of illustration, if you can get 10 units of energy out of a gallon of gas, and it only takes 4 units of energy to put that gallon of gas in your tank, then gas has a "net energy" of 6 units. On the other hand, if it actually takes 14 units of energy to pump, refine, transport, etc that gallon of gas into your tank, then gasoline has a net energy of negative 4 - It takes more energy to put it in your tank than what you get out of it when you use it to power the car.

How it's measured is under debate, and pretty darn complex, when you start thinking about it - Do you count the energy required to drill the hole that the crude oil is pumped out of? The energy required to make the drill in the first place? How about the energy to get it from the hole to the refinery? Obviously, you have to count the energy used in the actual refining process, but what about the energy used to make the hardware (from "dig the ore out of the ground", to "build the refinery") required to do the refining? What about transport from the refinery to the gas station? For that matter, what about the transportation mechanism? Do you count the fuel that gets burned to move it? The energy (Again, from digging the ore out of the ground, to making the parts and assembling them? And what about the factory (or factories) where this "making" takes place? The making of the tools and materials that put the factory together?) used in making the transport mechanism? How about the transfer from the gas station's tank into your car? Or the energy required to make the tools to make the materials to make the parts to build the factory to make the pumps that transfer the gas from the station's tanks to your car's tank? (And lets don't even get started on the energy required to make the tools/factory/etc to make the tank, or the energy used in getting it to the gas station to begin with, or the energy involved in the raw materials/tools/factory/etc to build the backhoe that burned energy digging the hole to bury the tank... You get the idea, right?)

Like I said, pretty darn complex...

Too complex for *ME* to keep track of it all, that's for sure...

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My point exactly. The earlier poster was throwing simple one sentence justifications that didn't make much sense.

You forgot to add in the amount of energy you spent on estimating the energy.

Like I said, too complex for me to keep track of it all! :)