Photovoltaic Cells Get Up To 10 Percent Efficiency - Which Is A Start

An unfortunate downside to the energy debate is that, when politics get involved, science goes out the window. The same activist groups that insisted ethanol would be the savior of the environment for 20 years (and were horribly wrong) now insist solar energy is the perfect solution.



It isn't, but it is getting better. Researchers in China and Switzerland are reporting the highest efficiency ever for a promising new genre of solar cells, called dye-sensitized solar cells, which some think offer the best hope for making the sun a mainstay source of energy in the future. The photovoltaic cells, also called Gräztel cells after Michael Gräztel, inventor of the first dye-sensitized solar cell, could expand the use of solar energy for homes, businesses, and other practical applications, the scientists say. Their study is scheduled for the November 13 issue of Physical Chemistry C.



Gräztel cells are less expensive than standard silicon-based solar cells and can be made into flexible sheets or coatings but have had serious drawbacks. They have not been efficient enough at converting light into electricity. And their performance dropped after relatively short exposures to sunlight.



In the new study, researchers including Gräztel describe lab tests of solar cells made with a new type of ruthenium-based dye that helps boost the light-harvesting ability. The new cells showed efficiencies as high as 10 percent, a record for this type of solar cell. The new cells also showed greater stability at high temperatures than previous formulas, retaining more than 90 percent of their initial output after 1,000 hours in full sunlight.



It may take 15 years for solar energy to be viable but it will be worth it, so there's no need to rush. As we learned from ethanol, the one thing worse than doing nothing is implementing the wrong solution and being stuck with it.



Article: Dong Shi, Nuttapol Pootrakulchote, Renzhi Li, Jin Guo, Yuan Wang, Shaik M. Zakeeruddin, Michael Grätzel, and Peng Wang, 'New Efficiency Records for Stable Dye-Sensitized Solar Cells with Low-Volatility and Ionic Liquid Electrolytes', J. Phys. Chem. C, 112 (44), 17046–17050, 2008. 10.1021/jp808018h