Catching Some Sun

In their initial applications-such as powering cell phones and laptops, as Konarka envisions-printed solar cells won't need to produce that much power or run for decades at a time. But scaling them up from personal electronics to rooftops is a whole other story.

Unlike the crystalline silicon in conventional solar panels, the polymers and dyes employed in printable solar cells are exquisitely sensitive to oxygen. Protecting these materials from blowing sand, intense sunlight, extreme temperature shifts, and the myriad other forms of abuse that nature heaps on solar panels will require hermetic seals. But Brian Gregg, a solar expert at the U.S. Department of Energy's National Renewable Energy Laboratory, predicts that materials scientists will soon develop workable seals that will protect the delicate devices over the long term. "There's no reason to believe that we can't make [printed] solar cells that will last for 30 years," says Gregg.

Indeed, the recent advances in printable solar cells-and the growing possibilities presented by nanotechnology-leave many experts more optimistic than ever that the technology is nearly ready to tackle one of the world's most troubling problems: how to create a ready and renewable supply of energy. Nanotech pioneer Richard Smalley, for one, is convinced that a solar-powered grid is not just possible but also inevitable-and indispensable. Nanotech could help solve the energy problem, Smalley contends, by providing new tools and materials that make widespread use of solar cells economically viable. But he believes it will take billions of dollars in funding and the focused efforts of the world's top chemists and physicists to make that happen. So for the past two years, he has been crisscrossing the United States, evangelizing for nothing short of a modern-day Manhattan Project to use nanotech to deliver a sustainable energy system.

That's the long-term vision. In the meantime, the Konarkas and Siemenses of the world are taking some critical first steps toward changing how we think about harvesting energy from the sun, and how we use electricity in our lives. It may not yet be the Manhattan Project urged by Smalley, but it's a fast-growing effort that could quickly reach critical mass.