The Hydrogen Car in Perspective

Colonel Claudius Crozet was a man of perspective. He would carefully weigh the decisions relating to our personal transportation destiny.

I want you to close your eyes and think back. I recognize that this will make it difficult to continue reading, so maybe we can just pretend. Think back to when you were in Kindergarten, 1st, or 2nd grade. What sorts of things were you learning? The alphabet? Simple words? Mathematically, you were probably learning addition, maybe subtraction, and what we would call planar shapes; that is, shapes that are two dimensional. Squares, circles, triangles are all planar shapes, for example. Fast forward to 9th grade Geometry. Now you are learning three-dimensional shapes. Suddenly, the rabbit hole is deeper. Two dimensional shapes are easy to render on paper; it is a two-dimensional medium. Three dimensional shapes are more difficult; this is the subject of a rather advanced field formerly known as projective geometry. I learned this in a very basic form in the second year of my engineering undergraduate course as a part of technical drawing. The problem with projective geometry is that the drawer is required to convey the most defining features of the three-dimensional object in question without obscurity and in as simple a fashion on a 2D medium. Hence, there are some things that you will see, there are some things that you won't.

This might seem like a bit of a flippant, technical digression from our usual programming here at FI, but it is, I hope, a clear metaphor for the issue of alternatively fueled vehicles. The problems that we faced during school were "two-dimensional," if you like. They were easily visualized, well-defined, and well-trodden. There was a well-defined beginning and end, as well. Finding a solution for the world's transportation needs--despite the hopes of many of our duly elected officials--is a "three-dimensional" problem. It has facets and characteristics that will appeal differently to different people. Most frustratingly, perhaps, is the fact that there may not be one solution. Rarely, in fact, is this the case. Often we have a preferred solution that seems like the only one, but it is just one choice out of many alternatives.

The Washington Post has run an interesting article about Congress continuing funding for research into hydrogen vehicles in the United States. Few technologies are as polarizing as the hydrogen fuel cell. There are those who insist it is the way forward. There are those who insist it is a pipe dream. The majority live somewhere in the middle. Understanding that this is a complex issue, and not wanting to wander too far off topic, allow me to posit a few statements on this issue in particular.

The Case for Hydrogen
In its favor, hydrogen is the most abundant element in the universe. The trouble is that it is often paired with something else. On Earth, this is often oxygen, in the form of water. Thus, to "free" the hydrogen it must be debonded from the oxygen. This costs you something. Proponents of hydrogen argue that, given hydrogen's abundance, if an effective and efficient method were developed for releasing it, it would automatically become profitable and viable. Using hydrogen in a fuel cell is a completely zero emissions process. By using a fuel cell to generate electricity, only water is produced. Thus, a relatively sustainable cycle is produced. Ideally the hydrogen consumed as fuel produces exactly the amount of water needed to return to fuel, again. Engineers refer to this as a "closed-loop" process. Theoretically, the vehicle itself could have a finite amount of water in the system that could be "electrolyzed" for power, with the water returning to be re-electrolyzed to continue the process.

Hydrogen can also be burned. This is what makes hydrogen unfortunately infamous. The world is very familiar with the internal combustion engine, however. Again, we would be reacting hydrogen in the presence of oxygen to produce only water vapor. Perhaps some other hydrocarbons or CO2 would be produced in trace amounts, but nowhere near the levels we see with the large-chain hydrocarbon fuels we use, today. Also, to just scrap so advanced a technology in favor of a less-understood alternative is something of a folly. We should always seek to build, technologically, rather than regress. BMW currently is the world leader in combustible hydrogen powered cars, though there are demonstrated difficulties with the technology.

One of the complaints levied against hydrogen is that it is not a viable short or medium-term greenhouse gas reducing fuel. This, however, is a somewhat ignorant complaint. Is science or engineering solely in the business of producing short or medium term solutions? Are not there experimental projects out there with no demonstrable public benefit? Developing an ultimately useless vehicle is not a sensible prospect for government. However, consider all the short-sighted comments that have been uttered in the past and proven silly by history. It was the chairman of IBM who said that computers would never fit into the room of a house; then the silicon microchip was invented and the rest, as they say, is history. The transistor was developed by Bell Labs; a research lab with ample funding and limited practical remit. The results produced by Bell Labs are continuing to pay technological dividends today. Could not the hydrogen economy benefit from such faith and monetary support? No, it may not be viable now, but our grandchildren could thank us.

The Case Against Hydrogen
The polemical side of the argument is, admittedly, easier and centers on three crucial fields: production, storage, and power.

Hydrogen is incredibly difficult to separate from oxygen. When compared with the streamlined process for converting crude oil into gasoline, electrolyzing water to produce hydrogen and oxygen gas seems wasteful, primitive, and stupid. Where does the electricity come from? Methane? Coal? Better yet, nuclear? The best method we currently have to produce hydrogen is by electrolyzing water, and the yields are appallingly small for the energy required. Furthermore, there are already cataclysmic water shortages in parts of the developing world that will only get worse as climate change occurs. Thus, many of the same criticisms levied against biofuels (they will require land used normally to produce food) can be levied against hydrogen production (it will require water necessary to irrigate land or nominally used for drinking). Yes, ocean water can be desalinated. This only increases the energy input and further swings the needle away from hydrogen.

Storage gets a lot of press, when it comes to criticizing hydrogen. It is, after all, the lightest element and, therefore, the least dense. To make hydrogen viable will require storing it at very cold temperatures (as a liquid) or under very high pressure (still, as a liquid). Yet, even with cryogenic hydrogen fuel, the hydrogen car will require a much larger fuel tank than its gasoline powered ancestor. Hydrogen is also volatile, flammable, and dangerous. For that matter, so are gasoline and alcohol. There are developments for storing hydrogen in a solid mixture, but then it must once again be separated out; renewing the same line of criticism previously levied.

Ultimately, though, this may really be a question of compromise and power. Engine Control Units (ECUs) have become so advanced over the past decade that drivers are used to having cars that produce 300 horsepower and can get 30 MPG on the highway. This odd juxtaposition is impossible without adaptive control of the air-fuel ratio. Despite all the computer enhancements, the internal combustion engine remains a massively inefficient device. Best estimates are that modern gasoline internal combustion engines have a thermodynamic limited efficiency of 37%. The majority of energy loss is as waste heat. Although a hydrogen ICE will run at a lower temperature--that is, with less heat loss--it will still not be perfect. Fuel cells, as well, will have finite performance limits. As demonstrated by the BMW Hydrogen 7, hydrogen has a lower energy density (energy available for power per unit weight). Thus, the MPG of a hydrogen ICE is markedly lower than that for a gasoline engine and it produces less power. Consumers will likely be unwilling to compromise on a step backwards from what they are used to, even if it would raise the likelihood of future benefits. After all, look how far the gasoline powered car has come.

Finally, this decision reeks of patronage. Once the government has set aside funding, good luck trying to take it away. 190 separate hydrogen projects? Would not 10 have done, let alone a couple of hundred? The development itself is proving to be mismanaged, wasteful, and devoid of any real urgency. While hydrogen may not be a sensible short or medium term solution, there are technologies that may be, and that would become so if they received the funding being sent down this questionable route.

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The choice should ultimately be made by the market. There were literally dozens of car manufacturers and various types of drive other than the gasoline engine at the turn of the 20th century. The market settled on the gasoline engine and a few manufacturers as being best. Now it is time once more to have a plethora of options available. Returning to our problem solving analogy, it is clear that this is a 3D problem. Consumers and decision-makers alike must ask themselves some very serious questions:

1) What problem are we trying to solve?
2) What technologies are available now?
3) What technologies show promise for the future?
4) Is the government the best suited for making a decision in this regard?
5) Is funding hydrogen research a good idea in the short term given its uncertain long-term potential?

These are questions that should not be simplified or idealized. After all, this is a three-dimensional world we're living in.