A hydrogen-fueled big rig rolled into the Port of Stockton last week, earning applause for its high-tech zero-emission system.
But reader Tom Burns says hydrogen vehicles actually have a bigger carbon footprint than traditional cars.
“That was a very interesting article about the quietness and power of the Big Rig powered by hydrogen in the July 2 Record and its producing no greenhouses, only water.
“However, what is not said by its manufacturer is the overall environmental cost of the use of hydrogen. Chemically or environmentally free hydrogen does not exist. Its existence is always in combination with some other chemical, and this bond is always difficult and energy consuming to break.
“The most most practical source if hydrogen is from water–hydrogen and oxygen. But the energy needed to separate the two is the same as the power generated in the truck engine if done at 100 % efficiency. But there is no way this can be done at this efficiency. Then the hydrogen must be compressed to extremely high pressures and run through costly (because of the high pressures) distributions systems in order to be used This uses up more energy (which cannot be recovered).
“So the total energy to get it is quite a bit more than what can be extracted. But the big blow is that this energy to produce it will generally come from greenhouse gas producing electric plants that run on natural gas, coal, or oil. Even if the power is from renewable sources such as photovoltaic or wind, that amount would have to be subtracted from its alternate use which would have to be replaced by greenhouse gas producing sources.
“In other words Hydrogen doesn’t get us anything. Overall, its use makes a somewhat bigger carbon footprint than the one it erases when used to fuel a vehicle. And no scientist has yet figured out a cheaper way of obtaining hydrogen.
“I don’t understand why people keep coming up with this hydrogen vehicle stuff: they don’t look at the overall picture, and the media doesn’t help. “