All this talk about hydrogen fuel-cell powered cars. Well, what about them?
Remember your high-school science class, when the teacher applied electricty to water with two electrodes? It would cause electrolysis of the water. The electrical energy would cause the H2O to to dissociate into hydrogen gas and oxygen:
2 H2O + energy = 2H2 + O2
Hydrogen fuel cells work in reverse (I won’t go into the details here). They combine oxygen and hydrogen gas to form water, and create energy.
2H2 + O2 = 2H20 + energy
Hydrogen is everywhere on our planet. Fuel cells don’t generate any CO2 or greenhouse gases, just water vapor and heat. Sounds great, doesn’t it? Wouldn’t it be wonderful if we could run our cars on hydrogen instead of gasoline?
Well, let’s think of this for a moment.
One way to get hydrogen is from steam reforming, where H2 is extracted from hydrocarbons, mostly from natural gas
However this process still takes energy, and still generates some greenhouse gases. So you’re basically still using hydrocarbons to indirectly power your car. There is some debate that this is a short-term solution. It still dosen’t remove us from our dependency from fossil fuels.
Another way to get hydrogen is to electrolyze water. But the problem is, the H’s and O’s like to be together in the form of H2O. It takes a certain amount of coaxing to get them apart. To do that, we need energy. (Just like your chemistry teacher had to use a small battery for the hydrogen/water experiment).
So where would we get that electrical energy to break down water into hydrogen? From our power-generating stations, naturally, which are based on coal, natural gas, nuclear or hydroelectricity.
Now, what if it happens that your electricity happens to comes from a coal-burning plant?
Well, then that defeats the WHOLE purpose of your fuel-cell car.
You’d basically be burning coal…to make electricity… to make hydrogen…to power your car. The net effect is you’d basically be burning COAL to run your car, which isn’t exactly the most environmentally-friendly source of fuel.
Sure, your car might not pollute the local neighborhood where you live, but it most definitely would, indirectly, near the coal-buring plant hundreds of miles away.
So much for zero emissions.
The only truly zero-emission way to power your hydrogen-fuel cell car would be to generate hydrogen from nuclear or hydroelectric power plants.
Well, lots of people oppose the building of hydro dams. Besides, there’s only so much hydroelectric power available (we’ve pretty much dammned up every significant river in North America already).
The most plausible answer seems to be to build more nuke plants to make more electricity. Which again, many people are opposed to.
So what’s the right choice? (Things are never as easy as they seem, are they?)
I”m not saying hydrogen-powered vehicles dont’ have a huge potential. Yes, we can have zero-emission vehicles that don’t depend on oil or gas.
We just need to be aware of where this hydrogen will come from, and what price we’re willing to pay to cover the associated costs of getting it to our cars.
The Deep Friar 