solar cells in the 1990s, and has reported on them in ACS journals and at ACS national
meetings.
Dye-sensitized cells are already being produced commercially, and the technology can
create energy from a broad spectrum of light, both indoors and outdoors. Because they are
relatively inexpensive and easy to produce, the cells are widely expected to become competitive in price with fossil fuels in the long term.
Compared to standard solar cells, the new cells work more like plants in the way they
convert sunlight to energy. If they use a dye that is structurally similar to chlorophyll, they
become green in color. They also are easier and less expensive to produce. Dye-sensitized
cells also have a longer working life than amorphous silicon-based solar cells, which have a 6
percent light conversion efficiency.
The revolutionary discoveries — the “eureka!” moments — that Dr. Orbach mentioned
earlier sometimes do happen suddenly, almost overnight. More often, however, the revolutions rise out of one-small-step advances, scientific discoveries that quietly build one atop
the other until we reach a tipping point.
Chemists, chemical engineers, and other scientists made many other advances toward
harnessing artificial photosynthesis in 2008. ACS’s 34 peer-reviewed scientific journals were
among the showcases.
Clean Energy Solutions
Artificial photosynthesis is based on solar energy, and solar is among the energy technologies that experts view as likely permanent solutions to global climate change. The others
already are in use and making contributions to reducing carbon dioxide emissions today.
Clean hydroelectric power, for instance, now supplies an estimated 20 percent of the world’s
electricity. Another 16 percent comes from nuclear power. What lies ahead for nuclear
power, which is available right now and releases no carbon dioxide? Dr. Jerald L. Schnoor,
editor of ACS’s Environmental Science & Technology, and a professor at the University of
Iowa, has these thoughts:
“Nuclear may become a bigger part. My students don’t like it when I say it, but I don’t
think we can rule out nuclear of the energy mix in the future for the simple reason that
we have to come to terms with how to dispose of the waste anyway. We have nuclear
