Long-time friend of the blog, and occasional corrector of the editor’s attempts at incorporating French into the proceedings, Colin Rush sent this link to a story about photonics in the Christian Science Monitor. “Wires 1/10,000th the diameter of a human hair can absorb more of the sun’s power than previously thought possible, a new study in Nature Photonics suggests,” writes David Unger, an energy correspondent for the Monitor. Unger’s lead paragraphs pushed your editor to look up several related terms and look further into the researchers’ own writing. “Although still years away from production, nanowire solar cells could push the conversion efficiency of the sun’s energy past the so-called Shockley-Queisser limit, which for decades has served as a fixed ceiling in solar energy research. “Such a breakthrough would be significant because the sun’s power is wildly abundant, but diffuse, and difficult to harvest. Even increasing the limit by a few percent would go a long way in making solar a more viable alternative to …
Solar Cells – All That Glitters Need Not Be Gold
The search for less expensive solar cells drives many lines of research these days, with trends toward smaller collectors and less expensive materials leading the way. Many solar cells use gold and other pricey metals to provide junctions within the cell structure. Gold closed Friday at $1,204.00 per troy ounce on the London Metal Exchange, and nickel at $10.01 per pound. That would make gold worth $17,558 per avoirdupois pound (14.583 troy ounces per pound), or 1,754 times more expensive than nickel. According to Gizmag, University of Toronto investigators found that substituting nickel for the previously used gold as collection contacts in their colloidal quantum dot solar cells provided equal performance, at a 40 to 80-percent drop in solar cell prices. Following that math, current pricing of solar cells such as Ascent’s thin film units at $6.00 per Watt could drop to $2.40 to $1.20 per Watt; near the $1.00 per Watt goal many cell makers have long sought. …