Electric cars aren’t necessarily green at all. Electric vehicles require large amounts of electricity – so much that Toronto Hydro chief Anthony Haines says he doesn’t know how he’d get it. “If you connect about 10 per cent of the homes on any given street with an electric car, the electricity system fails,” he said recently.
You cannot repeal the second law of thermodynamics.
Remember the electric-only Honda Clarity, that was advertised to use no gasoline at all?
The problem is that hydrogen is a fuel but not a resource. Hydrogen gas, H2, has to be made. It just can't be sucked out the air or water or earth. As I explained in "Buy a Honda, Kill a Polar Bear,"
where does the driver get the hydrogen to begin with? Hydrogen gas, H2, is not found free in nature. There are two ways to separate hydrogen from its compounds: hydrolysis and reforming. The former, most commonly and easily done with water, uses electricity and a catalyst to break H2O into H2 and O2. Reforming uses heat instead of electricity.
More than 90 percent of the hydrogen produced in the world is obtained by steam reforming of natural gas. It's not energy efficient since the energy gained from the hydrogen gas is less than the energy required to produce it. H2 produced in this manner is not used for fuel (except rocket fuel and some others exotics), but for industrial and chemical purposes. ...
That's the problem with fuel-cell or any other electrically-powered vehicle. There is no free way to produce the electricity. Since most electricity in the United States is produced by coal-fired plants, all that electric cars do is shift the environmental effects from the tailpipe to the power plant. This is not a good shift, since today's auto burn extremely cleanly already.
If the H2 is produced using electricity somewhere, then odds are that coal produces that electricity. So the CO2 production has been merely moved off the auto to another emitter. Also, does it take more energy to produce the H2, whatever the source, than the H2 supplies? If so, exactly what is the benefit of the Clarity?
The Globe and Mail makes the same point:
And if the extra electricity [needed to recharge electric cars] isn’t generated by renewable energy, then overall carbon dioxide emissions will go up, not down, Prof. Smil says. “The only way electric cars could reduce global carbon emissions would be if all the additional electricity needed to power them came from carbon-free energies.” He also makes the essential point that the world’s energy infrastructure is based on fossil fuels. Changing that will take decades.
Electric cars are not ready for mass market and never will be.
No comments:
Post a Comment