Wednesday, October 19, 2005

Hydrogen Hype

There is a widespread belief that the savior of the planet, in terms of an energy solution, will be hydrogen. I'm here to tell you that just ain't so. Hydrogen, as it occurs on the Earth, is not a primary energy source. It can be used as an energy carrier, like electricity, but it cannot replace fossil fuels, which are primary energy sources.

From Wikipedia:

There is a widely held misconception that hydrogen is an alternative energy source. There are no uncombined hydrogen reserves on Earth that could provide energy like fossil fuels or uranium. Uncombined hydrogen is instead produced with the help of other energy sources. It may play an important role in a future hydrogen economy as a general energy storage system, used both to smooth power output by intermittent power sources, like solar power, and as transportation fuel for vehicles. However, the idea is currently impractical: hydrogen is inefficient to produce, and expensive to store, transport, and convert back to electricity. New technology may change this in the future.

From Physics Today:

Although in many ways hydrogen is an attractive replacement for fossil fuels, it does not occur in nature as the fuel H2. Rather, it occurs in chemical compounds like water or hydrocarbons that must be chemically transformed to yield H2. Hydrogen, like electricity, is a carrier of energy, and like electricity, it must be produced from a natural resource. At present, most of the world's hydrogen is produced from natural gas by a process called steam reforming. However, producing hydrogen from fossil fuels would rob the hydrogen economy of much of its raison d'être: Steam reforming does not reduce the use of fossil fuels but rather shifts them from end use to an earlier production step; and it still releases carbon to the environment in the form of CO2. Thus, to achieve the benefits of the hydrogen economy, we must ultimately produce hydrogen from non−fossil resources, such as water, using a renewable energy source.

However, even using Hydrogen as an energy carrier has its drawbacks, as are demonstrated by Engineer-Poet here.

That's all I have to say about hydrogen. Lots of other people have said it better elsewhere.

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