Solar energy conversion offers a solution to help mitigate
global warming
(Download printable, PDF version.)
ARGONNE, Ill. (Mar. 6, 2007) — Solar energy has the power to reduce greenhouse
gases and provide increased energy efficiency, says a scientist at the U.S.
Department of Energy's Argonne National Laboratory, in a report (view
it online)
published in the March issue of Physics
Today.
Last month, the Intergovernmental
Panel on Climate Change (IPCC) of
the United Nations released a report confirming global warming is upon us and
attributing the growing threat to the man-made burning of fossil fuels.
Opportunities to increase solar energy conversion as an alternative to fossil
fuels are addressed in the Physics Today article, co-authored by George
Crabtree, senior scientist and director of Argonne's Materials
Science Division,
and Nathan Lewis, professor of Chemistry at Caltech and director of its Molecular
Materials Research Center.
Currently, between 80 percent and 85 percent of our energy comes from fossil
fuels. However, fossil fuel resources are of finite extent and are distributed
unevenly beneath Earth's surface. When fossil fuel is turned into useful energy
through combustion, it often produces environmental pollutants that are harmful
to human health and greenhouse gases that threaten the global climate. In contrast,
solar resources are widely available and have a benign effect on the environment
and climate, making it an appealing alternative energy source.
“Sunlight is not only the most plentiful energy resource on earth, it is also
one of the most versatile, converting readily to electricity, fuel and heat,” said
Crabtree. “The challenge is to raise its conversion efficiency by factors of
five or ten. That requires understanding the fundamental conversion phenomena
at the nanoscale. We are just scratching the surface of this rich research
field.”
Argonne carries out forefront basic research on all three solar conversion
routes. The laboratory is creating next-generation nanostructured solar cells
using sophisticated atomic layer deposition techniques that replace expensive
silicon with inexpensive titanium dioxide and chemical dyes. Its artificial
photosynthesis program imitates nature using simple chemical components to
convert sunlight, water and carbon dioxide directly into fuels like hydrogen,
methane and ethanol. Its program on thermoelectric materials takes heat from
the sun and converts it directly to electricity.
The Physics Today article is based on the conclusions contained in
the report of the Basic Energy Sciences Workshop on Solar Energy Utilization
sponsored by the U.S. Department of Energy. Crabtree and Lewis served as co-chairs
of the workshop and principal editors of the report. The key conclusions of
the report identified opportunities for higher solar energy efficiencies in
the areas of:
- Electricity – important research developments lie in the development of
new, less expensive materials for solar cells, including organics, thin films,
dyes and shuttle ions, and in understanding the dynamics of charge transfer
across nanostructured interfaces.
- Fuel – solar photons can be converted into chemical fuel more resourcefully
by breeding or genetically engineering designer plants, connecting natural
photosynthetic pathways in novel configurations and using artificial bio-inspired
nanoscale systems.
- Heat – controlling the size, density and distribution of nanodot inclusions
during bulk synthesis could enhance thermoelectric performance and achieve
more reliable and inexpensive electricity production from the sun's heat.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology.
The nation's first national laboratory, Argonne conducts leading-edge basic
and applied scientific research in virtually every scientific discipline. Argonne
researchers work closely with researchers from hundreds of companies, universities,
and federal, state and municipal agencies to help them solve their specific
problems, advance America 's scientific leadership and prepare the nation for
a better future. With employees from more than 60 nations, Argonne is managed
by UChicago
Argonne, LLC for
the U.S.
Department of Energy's Office
of Science.
For more information, please
contact Steve McGregor (630/252-5580 or media@anl.gov)
at Argonne.
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