October 05, 2008
Thin Rollable Photovoltaics Developed
Imagine installing photovoltaics almost as easily as carpet.
Researchers led by John Rogers, a professor of materials science and engineering at the University of Illinois in Urbana-Champagne, used a combination of etching and transfer printing to create arrays of silicon cells that are one-tenth the thickness of conventional cells. They demonstrated multiple possible designs for solar panels incorporating the microcells, including dense arrays flexible enough to bend around a pencil. "You could roll them up like a carpet, transport them in a van, and unfurl them onto a rooftop," Rogers says.
The thinness ought to lower costs as compared to conventional silicon photovoltaics (PV).
A thin layer on architectural glass is lightweight enough to allow vertical installation.
"We can make it thin enough that we can put it on plastic to make a rollable system. You can make it gray in the form of a film that could be added to architectural glass," said John Rogers of the University of Illinois at Urbana-Champaign, who led the research.
"It opens up spaces on the fronts of buildings as opportunities for solar energy," Rogers said in a telephone interview.
After waiting for decades for PV to become cost efficient and flexible to use I think the 2010s will be when PV finally takes off on a massive scale and becomes ubiquitous.
This must be about number 50 among similar breakthroughs for solar films.
The flexible, ultra thin, and ultra cheap film has been promised for decades. I believe one could find announcements like this from 1995 and maybe 1985. And from several continents.
After a while one becomes cynical, but fight that tendency. Sooner or later one method will be a huge winner.
That 50 different ways to make solar film have seen the light of day so far says to me there's still lots of room for cheaper and better. The ones available today are lower cost than ever before, more new designs and manufacturing methods keep being suggested and developed (as previous ones ramp up production) and I agree with K that sooner or later a huge winner will emerge. Yes, but will some competitor follow up with even better, cheaper ones after that?
I suspect solar film will settle on a rather standard production method within the next few years. Technology consolidates that way and runs for decades before a far better design is made. Radio, TV, airplanes, automobiles, fountain pens, phonographs, light bulbs and many other products were wildly diverse for a decade or so, then standardized for a few decades. Most are now gone and others are rapidly changing again.
At first you might think there was no standardization for airplanes. But look again. From about 1910 onward the standard design had wings at the midpoint center of gravity, a stabilizer aft, a dorsal fin for turning at the rear, a tubular fuselage, and traction rather than push propulsion.
Yet, the Wright Brothers airplane design had almost none of those features.
I expect solar film will standardize on the cheapest durable film and on the best materials for the solar capture circuits. The latter must be durable, somewhat efficient, use rather common elements, and be easy to uniformly apply to the base film.
Cost is the flip side of durability. If film can be cheap enough then a short life will be acceptable. You could just replace every few years.
After standarization it is unlikely that some newer design will dramatically change the process for a long time. Probably a print process or a spray process (think ink jet) will prove to be the winning application method. But it could also be an etching process with the desired patterns being projected into or onto a reactive base film.
I think there'll be several "standard" forms of PV going forward. Why? Different needs.
1) Vertical PV needs to be lighter than horizontal or tilted PV.
2) PV in deserts for big industrial projects has cheap land. Conversion fficiency isn't as much of an issue.
3) PV on roofs has limited space and higher conversion efficiency offers greater advantages.
4) New sloped roofs will eventually work better with integral PV. PV as roofing material. But flat roofs will have tilted PV on it and therefore the material needs (less need for structural function) will be different.
5) The wild card is solar concentrator technology. What it does is make higher efficiency PV more cost competitive against lower efficiency thin films.
I look at all these different engineering and economic needs (and this list is not complete) and it makes me think multiple PV technologies will survive, each for a different range of applications.