Skip to comments.Hydrogen Powered Cars! HA!
Posted on 01/25/2002 12:12:08 PM PST by John Jamieson
John R Jamieson MIT67, NASA67-94 retired
It seems like a great idea at first glance. Hydrogen is one of the most abundant elements on earth and burns very cleanly. It contains more energy per pound than any other fuel.
At second glance, things are a little less encouraging. Most of the hydrogen on earth is already burned! The oceans are the ashes of billions of years of hydrogen fires. The hydrogen is tightly bound to oxygen atoms and must be separated from those atoms before it can be used again. Using electrolysis, the hydrogen can be separated from the oxygen by putting in exactly the same amount of energy that will later be retrieved when the hydrogen is burned. Hydrogen, made from water, is thus an energy storage media like a battery, not an energy source. Neither the separation nor the recombination of this reversible process can happen at 100% efficiency. Waste heat is generated during each process. Because most of our electricity is generated by hydrocarbons, we would still be using hydrocarbons to run our cars. The inherent efficiency of the electrical energy generation process (about 40%) times the expected efficiency of the electrolysis process (about 50%) would indicate a hydrogen fuel price of about 5 times the price of fossil fuels.
The second major source of hydrogen is directly from hydrocarbons. Hydrocarbons contain both hydrogen and carbon; about twice as many hydrogen atoms than carbon atoms, but since a carbon atom weights 14 times more than a hydrogen atom, much more carbon by weight. When we drive our cars today, we burn about 5.3 pounds of carbon and .7 pound of hydrogen per gallon of gasoline. Hydrogen plus oxygen equals water, good; carbon plus oxygen equals carbon dioxide, bad (the same stuff we exhale!). If we could breakdown natural gas, methane, gasoline, or fuel oil to separate the hydrogen from the nasty carbon (on which all life is based) and sell the huge piles of carbon for enough to pay for the separation, about 3 gallons of liquid or an equivalent weight of gas (about 18 pounds) would yield about 2 pounds of hydrogen, which is the energy equivalent of 1 gallon of gasoline or 6 pounds of natural gas. Remember that burning the carbon would not be allowed. We could make diamonds with it. The net result is that hydrogen fuel cannot, ever, be made for less than 3 times the price of fossil fuels.
OK, what if we just ignore that fact that we cant make hydrogen economically. What do we do with it in an automobile? The logical answer is we burn it, in the same cars were driving today. Internal combustion engines basically dont care what provides the heat. There are a few minor problems: How do you seal up the leakiest substance known to man? How do you store enough in the car to go 300 miles? What happens in a freeway crash? Etc. But, these little issues can all be solved. IC engines will need water injection to lower peak cylinder temps so we dont make nasty NOX, but that technology is pretty well understood. Oh, but wait a minute, IC engines are nasty and unacceptable! Enter the miracle solution: FUEL CELLS!
FUEL CELLS work! There is about a $100,000,000 worth of them on each Space Shuttle generating the equivalent of almost 36 horsepower. Coleman just announced a real commercial home power generator that puts out 1.2 kilowatts for only $7,995 (Plus $100 per hydrogen canister that lasts for a few hours). GM just drove its latest fuel cell vehicle Hydrogen1 on an endurance test, 230 miles from LA to Los Vegas. They only had to stop 7 times for more hydrogen. Many other companies built fuel cell cars and tried to go along, but didnt make it. Zero to 50 was only 18 seconds.
The US department of energy recently set a goal of only $400 per kilowatt (about a horsepower, figuring electrical controller and motor efficiencies) for STATIONARY APPLICATIONS BY 2015. Wont they be surprised that Detroit is planning affordable family fuel cell automobiles by 2010! If Detroit gets to magic $400 per horsepower five years early, and makes it small enough and light enough to go in a family car, you too, could be driving a 200 horsepower family car for a little over $100,000 that burns hydrogen costing you $5 a gallon. What a deal! Youll drive it with pride knowing that your leaving no bad stuff in the air of your immediate area, while increasing the pollution of the poor people that live next to the power plant outside of town by a factor of 3 and increasing the importation (and probably the price) of Arab oil by a factor of three.
All this negativity aside, there is one and only one way to cheap automotive fuel, clean air and energy independence for this country. The answer is a massive, nuclear energy economy, probably fusion (hydrogen) powered. Hydrogen used for fusion generates power thousands of times more effectively than burning it with oxygen. A national effort equal to the Manhattan project or the Apollo program could develop fusion-powered electricity (and cheap hydrogen for automotive fuel) within 25 years. Then, we can truly say, were driving clean, fusion-powered cars. Electricity could be as cheap as 2 cents per kilowatt-hour and hydrogen for our cars, 40 cents per gallon. It is the only solution to the problem that has any economic, political, or engineering viability.
In the meantime, burn all the cheap Arab oil you can get and keep supporting the development our own fossil fuel sources for the day when we decide to shut the Arabs off!
It may not be possible to generate electricity with fusion power in a cost-effective way. For the last 30 years I've been reading that this goal is 10-20 years away. At least you've moved you projection out to 25 years away!
A billion years of such biological activety gave us the windfall of hydrocarbons we now have. I don't think you could eat enough beans to power even your lawn mower.
Methanol has a better chance whether in the internal combustion engine or in direct methanol fuel cells.
BTW, biodiesel is intriguing....and clean (more so than "normal diesel.)
If you could make the infrastructure supporting petroleum disappear overnight and then consider the cost of reinventing and rebuilding it -- it would seem imposible. So I'm skeptical of hydrogen, but still interested.
I've long felt that hydrogen will make more and more sense the more expensive fossil fuels are. Eventually, as demand increases for a fixed supply of fossil fuels, reserves will begin to deplete to the point where the low-hanging fruit has all been lopped off, and we have nothing left but the stuff that's more expensive to extract and refine. This will drive the price higher. Drive it up high enough, and expensive alternatives will actually become competitive. By that time, fuel efficiency will be in vogue again. It's all supply and demand, basic Econ 101.
What you didn't talk about, however, is the "hidden" environmental cost of fossil fuels. I'm not an environmentalist wacko, but growing up in So Cal, I appreciate that some real costs were added to driving cars (in the form of smog controls and unleaded fuels). I remember when, in the early 70's, the brown smog was so thick and vile that it made your eyes and lungs burn in the summer. Things are much better now then they were then.
Also, aren't they working on renewable methods of extracting hydrogen (such as biomass)? I know that these have not been fully realized, but then neither has fusion.
Otherwise, thanks for your informative post.