Sunday, August 9, 2015

See-Through Solar

Little piece at National Geographic on the coming technology of transparent solar cells. These are thin organic coatings applied to glass windows that capture mainly ultraviolet and infrared light, so they appear clear. The best efficiencies achieved so far are in the range of 10 percent, compared to 22% for an off-the-shelf solar cell right now, and 33% in the coming generation of hi-tech cells. But the manufacturing process is much cheaper, and when you consider how many square miles of windows we have in the developed world, the potential to deploy this technology is vast. One idea is to coat the glass of smart phones this way, so they would trickle charge whenever exposed to light.

But the real gain would come from coating the windows of skyscrapers -- ten percent of the solar energy that falls on a building like this is a lot.

One thing I wonder about is how long these films last -- it would not be difficult to install coated glass panels when a building is first constructed, but if they have to be replaced every five or seven years that would be a big problem.

1 comment:

G. Verloren said...

The fact that these coatings are organic might very well require them to be replaced regularly, just as you fear.

I can't speak with any authority on the matter whatsoever, but based off my quite limited knowledge of these sorts of things, my intuition would lead me to compare this technology to that of organic LEDs, which have historically been plagued with lifespan issues.

An actual electrical engineer would of course have a real clue - I could be way off base here, after all. But as I understand it, typically organic compounds are a lot less stable than synthetic ones, and suffer more from chemical breakdown and degredation as use is prolonged.

This is ultimately a problem with many kinds of plastics, however, including fully synthetic ones. For example, exposure to ultraviolet light is why old retro computer keyboards that started out clean and white end up yellowed or gray. Many window films already suffer from this kind of problem, clouding over time or starting to peel off, et cetera.

Replacement is always a concern. So the real question is can this film offset the cost of installation over the lifespan of a single coating, and if so, by how much?