July 2004

Solar-Cell Rollout

Breakthroughs in nanotech are making it possible to churn out cheap, flexible solar cells by the meter. Soon your cell phone may be powered by the sun.

By Peter Fairley

On the test benches of Konarka Technologies in Lowell, MA, a new kind of solar cell is being put through its paces. Strips of flexible plastic all but indistinguishable from photographic film bask under high-intensity lights. These strips, about 10 centimeters long and five centimeters wide, are converting the light into electricity. Wire a few of them together, and they generate enough power to run a small fan.

Solar cells, of course, are nothing new. But until now, solar power has required expensive silicon-based panels that have relegated it, largely, to niche applications like satellites and high-end homes. What's remarkable about Konarka's power-producing films is that they are cheap and easy to make, using a production line of coating machines and rollers. The process is more akin to the quick-and-dirty workings of a modern printing press than to the arcane rituals performed in the clean rooms of silicon solar-panel manufacturing. The company literally has rolls of the stuff; its engineers plan to cut off usable sheets as if it were saran wrap.

Konarka's technology is just one example of a new type of printable solar cell, or photovoltaic, that promises to go almost anywhere, paving the way for affordable and ubiquitous solar power. Not only are the cells inexpensive to produce-less than half the cost of conventional panels, for the same amount of power-but they're also lightweight and flexible, so they can be built into all sorts of surfaces. Flexible films laminated onto laptops and cell phones could provide a steady trickle of electricity, reducing the need to plug in for power. Solar cells mixed into automotive paint could allow the sun to charge the batteries of hybrid cars, reducing their need for fuel. Eventually, such solar cells could even cover buildings, providing power for the electricity grid.