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Arthur hault-Denger

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The Case for Hydrogen Fuel Cells [Feb. 23rd, 2006|08:12 am]
Arthur hault-Denger
A friend recently mentioned this website, which postulates the net results when the world population/consumption curve intersects the diminishing fossil fuel reserves curve. Not a pretty scenario at all, and this will begin to occur within the next few years. If events continue on their present course, the gloom and doomers may be right after all, a la The Road Warrior.  In case you may think this is some wacky fringe website, just Google the word 'oil' and see what comes up: this is the second site listed, right after Shell.

The replacement technology of choice seems to be the hydrogen fuel cell (at least for personal/family and light industrial use). It is easily obtainable, sustainable and cheap. Mercedes-Benz and Daimler-Chrysler have already produced prototype minivans, buses and automobiles  with this technology. Their performance rivals that of conventional vehicles in the same class. In my understanding, the bottleneck in the process of replacing the existing technology is getting infrastructure (refineries, distribution and safety measures) put in place.  Furthermore, there may come a day in the not-so-distant future where individual residences and multi-family dwellings have their own on-site fuel cell (everyone lives 'off the grid').  Won't it be great to be rid of all those utility poles and power lines!

Thoughts on this?
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Comments:
[User Picture]From: solarbird
2006-02-23 04:54 pm (UTC)

on hydrogen cars

The replacement technology of choice seems to be the hydrogen fuel cell (at least for personal/family and light industrial use). It is easily obtainable, sustainable and cheap.
Yeah, all of these things are false.

Don't get me wrong, it's a neat technology, and it's a nice battery system for, say, portable devices - probably better than anything we have now.

But it's a battery solution. Hydrogen+fuel cell is not an energy source, as much as it would be nice for there to be one. Current best estimates for to-the-pump efficiency in a completed distribution system are about 30% - that you get about one energy unit out for every three put in. (three for ten, but you get the idea.) That's in comparison to oil, which is currently 10 out for every 1 in - a thrty-fold delta. We'll have to come up with thirty times as much energy for transportation as we currently do, and that assumes you're only talking about replacing transportation uses. We do not have anything like the capability to do that in the medium or what business laughably calls the long term, barring a major breakthrough akin to the development of net-energy-gain fusion plus a 20-year infrastructure build time.

Let me repeat that: we have to generate thirty times as much energy for transportation as we currently do, without using oil.

(I strongly recommend you read the Hirsch Report for an introduction to the time-scale and cost of replacing oil, whenever peak production does hit. It takes no position on when that will be.)

Also, energy density is a severe problem. At 5,000 PSI (or 350 bar), hydrogen has one-quarter the energy density of gasolene, so range of vehicles using high-pressure hydrogen storage units onboard will have 1/4 the range of gasoline models. (You may note that the sample vehicles here have ranges between 75 and 95 miles per tank. You may also note they've experimented with other fuels in an attempt to gain higher energy density. These have other problems.) If you store it as a liquid, where it does have similar energy density, it has to be kept at supercold temperatures. And even with very good insulation, the energy required to keep it that way consumes the tank's fuel supply in a little over a day.

Further, all current fuel cell technologies are extremely expensive. I'm strongly for further development and I'm hoping that there will be substantial progress made in this area. This is one of the reasons we haven't seen fuel-cell-on-gasoline models come out; you use significantly less gasoline that way per mile, but it's so dramatically more expensive that it doesn't come close to balancing out in the end - and it'll stay that way until someone develops a new technology for it or comes up with really cheap sources of certain rare materials, like platinum.

While the extremely-limited-range solutions may work well in Europe and in a few American cities, and may well end up being adopted here as well, it will be in a much more travel-constrained environment. (Again, barring successful fusion processes, or similar.)
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[User Picture]From: arthur_denger
2006-02-23 07:29 pm (UTC)

Re: on hydrogen cars

"While the extremely-limited-range solutions may work well in Europe and in a few American cities, and may well end up being adopted here as well, it will be in a much more travel-constrained environment. (Again, barring successful fusion processes, or similar.)"

Americans may have to re-think their concept of travel. People have been travelling for thousands of years; it is merely the duration and mode of travel which has changed. We have hydrofoil and hovercraft technology, yet people still choose to travel by gondola, sailboat, canoe and kayak. The world's only supersonic air liner, the Concorde, has been permanently mothballed, in favor of more efficient technology. Likewise, hot air balloons, blimps and gliders are still utilized today, though they are in effect obsolescent technologies. Perhaps travelers will make more use of multiple mode travel in future (e.g. walk down the street, catch the light rail to the depot, hop on a high speed train for the long cross-country leg, disembark; then take a riverboat or ferry to their destination and rent a small automobile or cycle to visit multiple short to medium range destinations. Americans may by that time have moved beyond the idea of the proverbial 'road trip'.

Conversely, limited range and lack of power were two of the arguments used more than a hundred years ago by proponents of steam engine technology over the gasoline powered ICE. While I don't doubt the facts as you state them, those facts are indeed based on current technology levels, which, it must be assumed, will improve with sufficient investment of time and resources. I share your optimism on the possibility of a (cold?) fusion breakthrough -- but for the moment I am skeptical -- I really hope it doesn't turn out to be in the same category as anti-matter powered jet belts. (Hey, as soon as they are developed, I'm gettin' me one of those, too!)
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[User Picture]From: solarbird
2006-02-23 08:11 pm (UTC)

Re: on hydrogen cars

Americans may have to re-think their concept of travel.
Oh, I think they will. They won't like it, either, but, well, such is life. But it's not that simple; the average commute is something like 30 miles at this point? I don't have good numbers for that. Most Americans have to drive everywhere.

This is why, for the last couple of years, I have strongly recommend against buying any property putting you into this position.

But oil is far more than personal transportation, unfortunately. Every part of our economy is fundamentally oil-dependent. Food? Oil dependent to produce, natural gas dependent to grow (that's how they make chemical fertilisers), oil dependent to transport - around 1500 miles of transportation before it gets to your table.

Conversely, limited range and lack of power were two of the arguments used more than a hundred years ago by proponents of steam engine technology over the gasoline powered ICE.
Sure, but energy density is energy density, and gasoline's energy density is higher than that of coal or wood. They had that backwards.

those facts are indeed based on current technology levels, which, it must be assumed, will improve with sufficient investment of time and resources
Energy density is physics, not technology. And when planning energy future, I think it a very bad idea, particularly in our upcoming situation to rely on hopeful technological breakthroughs. (Note that these aren't incremental issues; they're breakthrough changes.)

I share your optimism on the possibility of a (cold?) fusion breakthrough
I am not actually at all optimistic about this. I would very much like to see it, and I would support a massive project to try to make it happen, but I am not optimistic about it. However, that isn't a liquid fuels solution.

I do not think we face an overall-energy-poor situation in the 30-year-ish timeframe. There are two many possible solutions that show tremendous promise. But portable, high-density fuel is a serious problem.
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[User Picture]From: arthur_denger
2006-02-23 07:57 pm (UTC)

Re: on hydrogen cars

...and in the interim, why not power your Mercedes with Mazola? Apparently, one guy is running his 1979 Turbo Diesel on used cooking oil.

http://www.willyoujoinus.com/discussion/?pid=4680

Maybe 'Grease IS the word!'
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[User Picture]From: solarbird
2006-02-23 08:21 pm (UTC)

Re: on hydrogen cars

This is part of the biodiesel family of fuels. They hold substantial promise - and are, in fact, a net energy gain, unlike hydrogen. I suspect this will be a part of the longer-term solution for transportation - along with a new and more generalist approach to development in general.

Ideally, I think we could probably manage the point that Japan is at now; everyone owns a car, but only uses it for emergencies and special occasions. For most daily getting around, everyone walks (or bikes) most places, with aid from transit.

In... less than ideal circumstances, oil production peaks in the near term and drops quickly - instead of 2%-3% annually, as is the typical model, more like 5% or more, for which there is a disturbing amount of evidence.

I again strongly urge you to read the Hirsch report to find out more about mitigation strategies for dealing with this eventual issue.
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[User Picture]From: solarbird
2006-02-23 08:28 pm (UTC)

Re: on hydrogen cars

Here, this is an interesting approach to air travel that does not rely on liquid fuels:

The Aeroscraft.
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