Tuesday, October 26, 2010
Organic photovoltaics: cheap? efficient?
Unlike traditional semiconductors (silicon, for example), organic PV employ carbon-based plastics, dyes, and nanostructures, and can be manufactured via a printing process: much cheaper than high temperature processing that is needed by inorganics.
Organic solar panels are also lighter, more flexible, and therefore promising for an extremely wide class of applications, from covering entire buildings to textile, to vehicles, etc.
The efficiency of organic PV is not as high as the silicon one, though. In April 2008 scientists announced a 6.1 percent energy conversion efficiency. At that time, the best organic PV was just a 4.8 percent efficiency one. A big step, then!
After the summer of the same year, in Santa Barbara, California, they claimed an efficiency of 6.5 percent. Consider that 7 percent efficiency is considered a threshold: above that, organic PV would be an effective choice for rooftops, for example. Not because they are more efficient than silicon (inorganic PV now reach an efficiency of 10 to 20 percent), but because of their low manufacturing cost.
Unfortunately there are scientists that are doubting these results. Because of measurement errors, and because this race to the best performance has strong economic incentives, we may face some cases of research groups "overestimating" their results.
It not only a matter of fairness: the main concern is that somebody starts investing money on a false claim and loses a lot of money, therefore shattering confidence in the field, organic solar panels.
When talking about new energy sources, it is extremely important that investments follow scientific, rigorous, and reasonable directions. Research activities in this field are expensive, we cannot afford to loose money on false myths and we cannot afford to loose credibility in front of the public.