The Manila Times

Future fuel?

ROUGH TRADE BEN KRITZ

IT makes sense, in a “think horses, not zebras” kind of way, that clean energy advocates look to hydrogen as a potential solution; hydrogen is the most abundant element in the universe.

For the technological optimists who believe that the answer to climate damage caused by humanity’s technological evolution is simply more of some better kind of technology, hydrogen power is irresistible because it offers the prospect of cleaner energy without requiring significant changes to lifestyles. The inevitability of having to alter one’s self-indulgent, 20th-century way of life is, after all, what terrifies the climate deniers into trying to convince themselves and others that climate change does not even exist.

In the interest of full disclosure, so to speak, I have enough personal exposure to the application of hydrogen power technology to want it to be a widespread clean energy solution, and to believe that it can be — eventually. Beginning in the late 1990s, my former employer BMW began working on hydrogen fuel cell systems for cars, as did other manufacturers, though those did and always will pale in comparison to Bavarian automotive engineering greatness and style. I am not an engineer; the part of the concept I was involved in was in helping to work out the [hypothetical] support logistics necessary for keeping hydrogen-powered cars fueled and serviced.

Even then, 20-odd years ago, the concept was deemed to have been effectively proven; the vehicles met or exceeded expectations in terms of performance, seemed to be equal to or very close in terms of reliability compared with conventionally fueled cars, and being able to manufacture and provide subsequent technical support for the vehicles (what we call aftersales) was deemed to be feasible. What it was not deemed to be, however, was at all economically practical or sensible; the investment in new technology, and most especially, the necessary infrastructure would have been massive, and the cost of the new components in the cars would have made them prohibitively expensive.

Jump ahead a couple of decades, and one might think that at least some of those obstacles would have been overcome, but one would be wrong. Hydrogen power is still a potential, perhaps even likely solution to fossil fuel dependence; but it remains a solution that is at best something that will not be realized for another decade or more, and then only if there is a massive effort to develop it through the cooperation of industry and governments.

As the state of the art in hydrogen technology remains about the same as it was at the end of the last century, it is difficult not to view it with some pessimism. The world needs clean energy solutions that can be deployed on a global scale immediately, otherwise, there will be no one here to enjoy the benefits of hydrogen or other exotic technologies in a decade or so.

How it works

The principle behind hydrogen fuel cell technology is fairly simple. Hydrogen, although it is explosively flammable, is not used directly as fuel, unless one is building a spaceship — it works very well as fuel in that application, but produces large amounts of nitrous oxide, which is a harmful pollutant. Rather, the hydrogen is mixed with oxygen across a catalyst in a containment vessel — i.e., the fuel cell — with the chemical process producing electricity, a small amount of heat, and water vapor as exhaust.

The electricity generated can then be used to power a motor, such as in a car, or the fuel cell can be used as an energy storage device. If you have seen the movie “Apollo 13,” the thing that exploded and caused all the problems was one of the spacecraft’s oxygen tanks supplying its fuel cells, which in turn wiped out much of the ship’s electricity supply.

The main advantage of a fuel cell is that it produces practically no harmful emissions; water vapor is actually a greenhouse gas, but it would take many times the number of motor vehicles in existence, if they were all using hydrogen, to create enough water vapor to cause any real concern. In a motor vehicle application, a typical fuel cell provides a longer range than a comparable battery-powered car, and has the significant advantage of being rechargeable — in other words, refilling the hydrogen supply — in two or three minutes, versus 30 minutes to several hours for a battery-powered car.

Not so fast…

Hydrogen power, however, has some significant downsides. Hydrogen is extremely flammable when mixed with air, so safe handling and storage — including maintaining an extreme degree of quality control in fuel cells themselves — is essential. The production of hydrogen can be carried out in several ways, but all of them are extremely energy-intensive; if conventional, emissionsheavy forms of electricity generation are used to produce hydrogen — as is the case for about 95 percent of the current hydrogen supply — any environmental benefit is lost.

Likewise, even though hydrogen does produce sufficient electrical power to drive a vehicle or provide stored energy for an electrical grid, its efficiency is actually rather poor. Round-trip efficiency, or in other words, the total amount of energy put into a fuel cell that is eventually retrieved, is only about 30 percent for hydrogen, according to the US Energy Information Agency. By contrast, a run-of-themill lithium battery has about 95 percent round-trip efficiency.

Hydrogen power is also expensive, which is the main reason for its not having been adopted on a wider scale. The catalyst and electrodes used in a fuel cell use platinum and iridium, too costly and not particularly abundant elements. The biggest cost comes from transporting and storing hydrogen; as it is a low-volume gas, the only way it can be stored in useful quantities is in a liquid state, which requires a constant temperature of below -253 degrees Celsius to prevent evaporation. This makes building an adequate infrastructure to make fuel cell vehicles commercially viable prohibitively expensive. You can dump gasoline into an ordinary tank to supply petrol-powered cars, you can hook a charging station for battery-powered cars to the existing electric grid, but a fuel station for hydrogen is a couple of orders of magnitude more complicated. And that doesn’t even take into account the energy required to power a cryogenic storage unit, and — keeping in mind that hydrogen goes boom if not kept in a safe state — making absolutely sure that the storage unit’s power supply is never interrupted for even a moment.

As I said, hydrogen power is feasible, and I still hold out hope that continuing development will make it practical in the foreseeable future. But that is a future that will only happen if there is a coordinated effort to make it happen, and that cannot be done at the expense of more immediate solutions.

Front Page

en-ph

2022-09-27T07:00:00.0000000Z

2022-09-27T07:00:00.0000000Z

https://digitaledition.manilatimes.net/article/281496460155992

The Manila Times