Plastic Solar - Threshold of Revolution

While we were going all ga-ga over nanotech based solar photovoltaics, a major comeback of sorts has been achieved from a less celebrated source - plastic solar cells.

Researchers at a Danish group Risø claimed they have built plastic solar cells that cost less than 2% of silicon cells. So where one square meter of silicon cells would cost $800, plastic solar would cost only $15. Of course the revolution is still not on us, and here is why.

Plastic cells are not new and have been around for a while. But while earlier they only had a life span of a few days, the researchers at Risø claim their cells last two and a half years. So that is still workable. The problem remains the efficiency. While silicon cells manage 12% to 15% efficiency (in labs they have managed 50%), the plastic cells only manage 0.2% to 5%.

But come to think of it, even at 0.2% 5% efficiency with a life span of just 2.5 years, at $15 a sq m, it is still close to being competitive. As Jamais Cascio comments on his own post, "Assuming 50 watts power for a pessimistic average of 2 usable hours/day x 200 usable days/year, for 2.5 years and $15, the result is (by my calculations) thirty cents/kilowatt-hour. A place with better sunlight patterns would be close to competitive (e.g., 5 usable hours x 300 days/year, otherwise the same, equals 8 cents/kwh)."

A lot of places in India would fall in the "place with better sunlight patterns" category. 8 cents/kwh translates to about Rs 3.5 per unit. So even if the average efficiency is increased from 0.2% (the lower limit) to 0.4% (still very far from the current upper limit) 5% to 10%, we get power at Rs 1.75 per unit, which is less that say the Rs 2.25 that MSEB will pay Dabhol. And Rs 2.25 is almost considered a steal at current world gas prices.

Some years from now, will you remember that you read about it here first (or at least at all!)? :)