A proof-of-concept
device built by MIT researchers demonstrates the principle of
a two-stage
process to make incandescent bulbs more efficient. This device already
achieves
efficiency comparable to some compact fluorescent and LED bulbs.
Courtesy of the researchers
(January 11, 2016) Traditional
light bulbs, thought to be well on their way to oblivion, may receive a
reprieve thanks to a technological breakthrough.
Incandescent lighting and its warm, familiar glow is well
over a century old yet survives virtually unchanged in homes around the world.
That is changing fast, however, as regulations aimed at improving energy
efficiency are phasing out the old bulbs in favor of more efficient compact
fluorescent bulbs (CFLs) and newer light-emitting diode bulbs (LEDs).
Incandescent bulbs, commercially developed by Thomas Edison
(and still used by cartoonists as the symbol of inventive insight), work by
heating a thin tungsten wire to temperatures of around 2,700 degrees Celsius.
That hot wire emits what is known as black body radiation, a very broad
spectrum of light that provides a warm look and a faithful rendering of all
colors in a scene.
But these bulbs have always suffered from one major problem:
More than 95 percent of the energy that goes into them is wasted, most of it as
heat. That’s why country after country has banned or is phasing out the
inefficient technology. Now, researchers at MIT and Purdue University may have
found a way to change all that.
The new findings are reported in the journal Nature
Nanotechnology by three MIT professors — Marin Soljačić, professor of physics;
John Joannopoulos, the Francis Wright Davis Professor of physics; and Gang
Chen, the Carl Richard Soderberg Professor in Power Engineering — as well as
MIT principal research scientist Ivan Celanovic, postdoc Ognjen Ilic, and
Purdue physics professor (and MIT alumnus) Peter Bermel PhD ’07.