Geek in progress

There has been much ado the last days about a bus built by Van Hool. The vehicle uses an engine that uses hydrogen to generate electricity, emits water, and uses energy captured when breaking to charge batteries it can later use when accelerating again.

I must admit that this seems like a very good thing, until one starts to think a bit further. First the plus points. If all cars use this system, we would not have all the filthy emissions of exhaust fumes in our cities. Second, we might save some energy, because of the break-energy-capture system. But what about the drawbacks? The media seem to focus only on these benefits. However, the hydrogen needs to be acquired somewhere, right?

There are several ways to do this. One of them is electrolysis, but that does not seem to be the most efficient technique around. Even if it is, you need to generate that electricity somewhere. For example using wind. The question then remains if it would not be better to directly use that electricity instead of ‘storing’ the energy in hydrogen that is to be used later. Afaik, storing energy in some intermediate carrier always causes the loss of some portion of said energy.

Another way is by tranforming gas, which is the technique employed right now to acquire hydrogen for the hybrid bus. Methane can be split into carbon monoxide and hydrogen, using a bit of water. But the temperatures required for this are high (700 – 1100 degrees celsius), so a bit of methane must be burned, yielding, indeed, carbon dioxide. The carbon monoxide can be further processed at a lower temperature, again reacting with water, to form carbon dioxide (well, well … did we not try to avoid this?) and hydrogen and some left over energy.

So either way, if we think that going hybrid on hydrogen is going to solve all the issues, we’re very wrong, and the media should do a better job of reporting not only the benefits, but also the drawbacks. That said, I am in favour of cleaner forms of energy, and I’m quite certain that reducing smog is a benefit that is not ot be underestimated.