Thursday, April 12, 2012

The Unattainable Hydrogen Dream

I gave a talk at a local Resident's Association the other day, about the Pattullo replacement. Anyways, at one point, I stated my own personal belief that 40 years from now, there would not be as many automobiles anymore because of the rising price of oil, and that we needed to start building for that future.

A gentleman in the audience responded that according to him, the solution was electric cars. But not battery-electric cars, no; fuel cell electric cars. I didn't answer...I must admit that the fact that there are people out there who still believe that "business-as-usual" is possible with fuel cell vehicles simply left me speechless...

So let's talk a bit about fuel cells. A fuel cell is very similar to the more familiar battery, in which chemistry is used to generate electricty. A battery is a closed system and you don't put more fuel into it. It gets exhausted once the chemical reaction has gone all the way, and the battery is then dead. With a rechargeable battery (lead-acid in your car, NiMH or NiCad in your camera, and Li-ion in your laptop) you can apply a voltage and run the chemical reaction in reverse, regenerating the "fuel" so you can use the battery as a power source again.

A fuel cell is basically the same idea, except that you add a constant stream of chemical fuel to it instead of trying to regenerate it.

The most popular fuel cells run on hydrogen. That is, they use hydrogen as a fuel, and require constant top-ups to keep generating electricity. Obviously, the hydrogen highway that the gentleman in my audience envisioned requires a massive rebuild of our gas-station infrastructure, together with a steady supply of hydrogen as fuel.

So, where do you get hydrogen? More to the point, how do you make it? One way is by electricity - run a current through water and split it into H2 and O2. Mostly, though, it's made from natural gas plus a bunch of chemical-engineering magic (known as "steam reforming"). The magic involves the production of copious amounts of CO2, by the way, so this is hardly an "emissons-free" form of transportation. Once you've got the hydrogen, you'll need to compress it to ship it anywhere. This requires more ... electricity.

In any case, the idea of a fuel cell seems completely pointless to me. After all, both electricity and natural gas can be used directly to drive your car. These are available and (relatively) affordable today. Where's the advantage to moving to fuel cells? It's not going to be any cheaper (car-sized fuel cells are very, very, very expensive and are not currently in production), and is certainly going to be less efficient (ie. reqiure more energy in the end) than just using the primary power source directly!

There are still car companies working on fuel-cell vehicles. But a lot of these companies are refocussing on the battery-electric and hybrid gas/electric vehicles. Ballard, for instance, has gotten out of the automotive fuel cell industry entirely and is now making small, hand-held fuel cells for laptops and cell phones. And still not market-ready, after a good decade of R&D. Honestly, I don't think there will be a huge push for fuel-cell cars.

To really move to fuel-cell cars on a large scale requires the same infrastructure rebuild as rechargeable electric cars: a new set of fuelling stations. This is a huge project, which I don't see governments taking on, and which I don't think any car company is going to do by itself, either. I mean, rechargeable electric cars are going to be hard enough to get going on a large scale!

I'd really rather concentrate our remaining resources on (electric) mass transit and goods movement, not on continuing our love affair with the private automobile.

1 comment:

  1. Cars are not good for the environment, society, and humans. Period.

    40 years from now!!! A long-term vision.

    This is NOT about the environment, NOT about sustainability or CO2 or Gas Prices.

    This IS about the happiness and livability of our cities, and CLEARLY, cars does not belong in cities.

    FOI, currently, only 2 hybrid vehicles give gas savings considering the higher purchasing cost: Lincon MKZ and Toyota Puris.

    The Fuel cells must cost thrice as much.

    ReplyDelete