Page 35 - Environmental Nanotechnology Applications and Impacts of Nanomaterials

Nanotechnology and Our Energy Challenge 21

In the May 2004 issue of Physical Review Letters, a team from Los
Alamos National Laboratory found that quantum dots produce as many
as three electrons from one high energy photon of sunlight. When today’s
photovoltaic solar cells absorb a photon of sunlight, the energy gets
converted to one electron, and the rest is lost as heat. This nanotech-
nology method could boost the efficiency from today’s solar cells of
20–30 percent to 65 percent.
Global electricity demand has been expanding at a rate of 3.0 percent
per year since 1980, resulting in an overall increase of 88 percent to
13,934 bkwh, up from 7,417 bkwh. World electricity demand is expected
to double by 2030, growing at an annual rate of about 2.4 percent, as
economic activity is enhanced in developing nations such as China and
India. U.S. electricity demand grew from 2,094 bkwh in 1980 to
3,602 bkwh in 2005, or an average annual rate of 2.6 percent. U.S. elec-
tricity demand is projected to increase by 1.9 percent per annum by 2020.
Still, much of the world’s population will remain without modern
energy services unless new, aggressive policies and emerging technolo-
gies are launched in the coming years. The global electricity sector will
require as much as $10 trillion in new investments over the next three
decades, according to the International Energy Agency (IEA). This is
close to three times higher in real terms than the investment made in
the sector over the past three decades. Substantial investment will go into
transmission and distribution networks. In the developing world alone,
$5 trillion in spending in new electricity infrastructure will be needed to
meet projected targets for economic growth and social development.
The advantages of developing a new, improved, and more efficient grid
system are tremendous. But there are clear technological and political
hurdles that must be overcome to achieve this target. New materials and
new technical approaches will need to be developed and an elaborative
plan must be sculpted to map a smooth transition into an electrically
digital society. Nanotechnology holds great promise for the electricity
sector through its ability to enhance the new grid by introducing post-
silicon power electronics and complex, iterative, adaptive controls.
By supplying electrical systems with nanosensors and nanosources as
well as nanochips able to apply concepts of distributed business, adap-
tive learning, simulation, micro-real options, and work-flows while per-
forming peer-to-peer assessment, major changes can occur in terms of
energy efficiency and energy supply.
A new national initiative is being pursued to produce solid-state
lighting—light emitting diodes (LEDs) and lasers—that promises to be
ten times more efficient and two times brighter than incandescent and
fluorescent lights, respectively. General lighting is responsible for 20 per-
cent of global energy consumption, and conventional light sources offer
very low energy efficiencies of 5 percent for incandescent and 25 percent