by Richard T. Stuebi
For years, the utopian vision for powering humankind’s energy requirements has been based on hydrogen, produced by decomposing ever-abundant water (H2O), via renewable sources of power (e.g., sunlight). When hydrogen is used in fuel cells to produce electricity on-demand, the only by-products of the chemical reaction are water vapor and pure oxygen. In other words, an energy cycle that is infinitely sustainable (at least as long as we have a sun).
Of course, there are a number of well-documented challenges to achieving the so-called hydrogen economy. Producing, transporting and storing the hydrogen are all expensive relative to the current conventional energy approaches — and require a major change-out of infrastructure, which would entail a massive societal investment. Fuel cells also remain expensive, due to high materials costs and short lifetimes, until further engineering obstacles are overcome.
With this as backdrop, it’s interesting to read “Sun + Water = Fuel”, an article in the current Technology Review. The article profiles the work of Daniel Nocera, a professor of chemistry at MIT, who claims to have discovered a catalyst that facilitates a reaction in which oxygen is generated from water by sunlight — making, in effect, an artificial leaf. Of course, if one produces oxygen from water, one is also producing free hydrogen.
Therefore, Prof. Nocera is suggesting that he is on the verge of discovering how to produce hydrogen from water via sunlight. If true, this would be a major breakthrough towards the hydrogen economy, dramatically simplifying the hydrogen production, storage and transportation issues, because water and sunlight are respectively inexpensive and free — not to mention almost ubiquitous.
That being said, we must be cautious to avoid getting prematurely overexcited. To illustrate, let’s not forget the promising claims made in 1989 by Pons and Fleischmann of cold-fusion: twenty years hence, and other than lots of controversy, not much to show for it. And, even if Prof. Nocera is really onto something, there’s still the little issue of repairing hydrogen’s public reputation in the wake of the Hindenburg disaster: seventy years later, and many urban legends about hydrogen’s dangers still linger, as in this recent satire.
This reveals a constant occupational hazard for those of us who work in the cleantech field: things just don’t change as fast as we often would like for them to change. In the case of hydrogen, many things must change, and some of the changes — technical, institutional and cultural — must be profound, for hydrogen to become a major actor in the world’s energy economy. I hope that day comes far sooner than I frankly expect it will.