Nanowire Forests Use Sunlight To Split Water 56
An anonymous reader sends this excerpt from IEEE Spectrum's Nanoclast blog:
"One of the fundamental problems with fuel cells has been the cost of producing hydrogen. While hydrogen is, of course, the most abundant element, it attaches itself to other elements like nitrogen or fluorine, and perhaps most ubiquitously to oxygen to create the water molecule. ... Now researchers at University of California, San Diego have developed a quite different approach to mimicking photosynthesis for splitting water molecules by using a 3D branched nanowire array that looks like a forest of trees. ... The nanowire forest [uses] the process of photoelectrochemical water-splitting to produce hydrogen gas. The method used by the researchers, which was published in the journal Nanoscale (abstract), found that the forest structure of the nanowires, which has a massive amount of surface area, not only captured more light than flat planar designs, but also produced more hydrogen gas."
Re:Abundant where? (Score:3, Informative)
Re:Efficiency? (Score:5, Informative)
At what point will the technology provide more useful energy output than is required to manufacture and maintain the system? Will it substantially reduce fossil fuel usage, or is it another ruse, like the wind farms?
Oh dear, a Slashdot poster has made what appears to be a false claim about the EROI of wind farms.
Time to google around a bit and see if there's anything to it [academia.edu]....
This analysis reviews and synthesizes the literature on net energy return for electric power generation by wind turbines. Energy return on investment (EROI) is the ratio of energy delivered to energy costs. [...] Our survey shows an average EROI for just the operational studies is 19.8 (n=60; std. dev=13.7) This places wind in a favorable position relative to fossil fuels, nuclear, and solar power generation technologies in terms of EROI."
So, to sum up the above summary -- parent poster is wrong. As a matter of historical record, the average wind farm produces about 20 times more much energy than it expends on construction and maintenance.