Replacing
the Edison lightbulb with solid-state light-emitting devices (LEDs)
made sense considering that many lighting developers thought it would
reduce electrical usage worldwide. However, a new study argues that
increased lighting efficiency will not
cause a decline in electricity production because people
will just use more of it, keeping the amount of electrical usage
steady.
It
is often thought that a decrease in electrical usage worldwide would
add to the "green" cause by reducing the number of power
plants. But according to Jeff Tsao, the leader of the study and
an LED researcher from Sandia
National Laboratories, people will only use more electricity when
presented with cheaper lighting. He also noted that this has been a
pattern over recent centuries, dating as far back as A.D. 1700 as
humanity moved from candle to oil to gas to electricity. The study
claims that light use has remained "a constant fraction of per
capita gross domestic product" as different, newer types of
lighting came about.
"Over
the past three centuries, according to well-accepted studies from a
range of sources, the world has spent about 0.72 percent of the
world's per capita gross domestic product on artificial
lighting," said Tsao. This is so for England in 1700, in the
underdeveloped world not on the grid and in the developed world using
the most advanced lighting technologies. There may be little reason
to expect a different future response from our species."
According
to Tsao, there is a good side to this. With better artificial
illumination, Tsao says it will increase human productivity because
light in the workspace, especially in the shorter days of winter,
increases creativity and awareness. Also, better lighting helps aid
those who have vision loss.
"More
fuel-efficient cars don't necessarily mean we drive less; we may
drive more," said Jerry Simmons, coauthor of the paper and also
a researcher from Sandia National Laboratories. "It's a tension
between supply and demand. So, improvements in light-efficient
technologies may not be enough to affect energy shortages and climate
change. Enlightened policy decisions may be necessary to partner
with the technologies to have big impacts."
On
the other hand, there are concerns with light pollution from too much
light. But Tsao mentioned that the new solid-state lighting is
digitally controlled more precisely in space and time, and would
allow humans to preserve darkness when necessary.
The
study was published in the Journal
of Physics D just
this month. Other contributing authors of the paper include Harry
Saunders of Decision Processes Inc., Randy Creighton and Mike
Coltrin, both from Sandia National Laboratories.