When looking at technology, it is easy to focus just on
the most bleeding-edge things – genetic medicine, nanotechnology, or quantum
computing. No question, it's amazing what we've accomplished. But these
things are happening in labs far removed from our everyday lives.
There is also change going on right at our fingertips
in an industry that touches billions of people every day, yet to which few of
them ever really give much thought. Despite that, hundreds of scientists in
many countries are continually at work, trying to reinvent this now
centuries-old "technology" using semiconductors, nano-scale engineering, even biology. All to improve the
seemingly simplest of devices – the light bulb.
Despite the dim (ahem) interest, lighting accounts for
more than 15% of global electricity usage, and is a $50-billion-per-year
industry. Today we look at a fundamental shift in lighting technology; away
from long-established market leaders, this is now being accelerated by policy
around the world.
In the Beginning
Of all human accomplishments, the control of fire ranks
near the top of the list in terms of importance. It was, along with creation
of crude stone tools, among the first technological breakthroughs – the
first times we manipulated nature to create tools for ourselves that would
improve quality (and length) of life in a dramatic way.
No one knows when fire was first harnessed by human
beings. A conservative guess would be about a half-million years ago,
although other estimates place it as far back as two million. In any event,
it probably came about after some prehistoric savant had an "Aha!"
moment and deduced that it was possible to preserve a few embers after a
lightning strike… and then, that they could be carried from place to
place, enabling a perpetual renewal of the flame. To be appointed keeper of
the fire was likely a great honor.
Fire bestows upon its users many gifts. It warms living
spaces, it can be used to cook food, and it is a weapon against predators.
But it is also a source of light, serving as a surrogate sun and prolonging
the possibility of human activity into the nighttime hours. Early humans were
freed to gather around the hearth after dark, to work, to socialize, and
– as language evolved – to tell each other stories.
Over time, humans have created light by burning just
about anything flammable, from wood to whale oil to gas. But using actual
fire as a light source has a lot of drawbacks. It's impractical: you need to
constantly maintain your fuel supply. It's inefficient: the great majority of
the energy is lost as heat. And it's dangerous, always a threat to spread if
In order to take the next step on the long road to Las
Vegas Boulevard, people needed something better. That thing happened to come
in the form of a vacuum-sealed glass chamber filled with electroluminescent
materials – the now-ubiquitous incandescent light bulb.
The invention of this bulb is most often – and
mistakenly – attributed to the Wizard of Menlo Park, Thomas Edison. In
truth, its antecedents date back to 1802, when the great British scientist
Sir Humphry Davy demonstrated incandescence for the
first time by passing an electric current through a thin strip of platinum,
chosen because of its high melting point. It didn't work very well, but the
principle was established.
After Davy set the stage, it was off to the races. Over
the ensuing decades, experimenters fiddled with many different combinations
of metal wires, carbon rods, and evacuated or semi-evacuated enclosures.
It wasn't until much later – in 1879 – that the 32-year-old Edison started coming close to a
commercially feasible version of the incandescent light, with a
carbon-filament lamp. In 1880, he created a carbonized bamboo filament with a
working life previously unimagined, of over 1,200 hours.
Carbon, however, was not destined to become the
standard for filaments. Tungsten – which lasted longer and gave a
brighter light – was. In 1906, the General Electric Company patented a
method of making filaments from sintered tungsten and, in 1911, used ductile
tungsten wire for incandescent light bulbs. Then, in 1913, GE's Irving
Langmuir found that filling a lamp with inert gas instead of a vacuum
resulted in twice the luminous efficacy and a reduction in bulb blackening.
Thus was born the incandescent lamp as we know it; it
has survived relatively unchanged for the past century.
- Outline of glass bulb
- Low-pressure inert gas (argon, neon, nitrogen)
- Tungsten filament
- Contact wire (goes out of stem)
- Contact ire (goes into stem)
- Contact wire (goes out of stem)
- Electrical contact
While technology progresses more rapidly in the Information
Age than it did in the preceding centuries, the incubation time from
invention to commercialization continues to be a defining trend for
technology. In a commodity industry such as lighting it is especially
important, as the economies of scale push down the commercially tolerable
price for mass adoption to incredibly low levels. There are, however, ways to
enter the market and expand over time. There is no better example than the
incandescent bulb's most effective competitor to
The modern incandescent gives off a light that's fairly
close to sunlight. People are used to it. They like it. However, the problem
with these bulbs has always been their inefficiency. Ninety percent or more
of the energy used to get the filament to glow is dissipated as heat…
not as bad as a fire, but still hardly a best in show.
This inefficiency and the associated large electrical
cost per lumen (the standard measurement of light, a photonic equivalent to a
gram or meter) left a big opening for competitive technologies. And, as
technologists tend to do with such an obvious problem, over the course of the
past century, numerous alternatives have been introduced, including: sodium
vapor, neon, xenon, carbon arc, and many others. Some of these specialized
lights are still in use today in niche applications. But, for one reason or
another – short lifespan, too many toxic chemicals, or simply too
expensive – none was suitable for everyday lighting.
Nearly from the beginning, the only real challenger has
been the fluorescent lamp.
Fluorescents are tubes containing pressurized mercury
vapor. When an electrical current is passed through them, the excited mercury
atoms produce short-wave ultraviolet light that then causes phosphors coating
the tube's interior to fluoresce, producing visible light.
Again, understanding of the principle goes back to the
mid-19th century; all the proper elements were available by the
1920s. But producing a workable model took even longer than with incandescents. The tubes may look simple, but they're
The main difficulty is that fluorescent lamps are "negative differential resistance" devices, which means
that as more current flows through them, electrical resistance drops,
allowing even more current to flow, and so on. So you can't connect one
directly to a constant-voltage power supply and walk away; pretty soon, it
would self-destruct under the buildup of current. To prevent this, you have
to have something in between – a ballast – to continually
regulate the current flow through the tube.
There were plenty of other problems, too. It wasn't
until 1934 that GE finally rolled out its prototype. As one industry
historian wrote of the event: "A great deal of experimentation had to be
done on lamp sizes and shapes, cathode construction, gas pressures of both
argon and mercury vapor, colors of fluorescent powders, methods of attaching
them to the inside of the tube, and other details of the lamp and its
auxiliaries before the new device was ready for the public."
With the cost savings they afforded, fluorescents were
quickly adopted by schools, businesses, municipal buildings, and such. By
1951, more light in the US was produced by them than by incandescents.
But because, for a long time, they could only be made
in long tubes (either straight or with several U-shaped bends), they failed to catch on in home lighting. And even if
they'd been initially adaptable, few would have chosen them. People hated the
cold, harsh light they gave off, that they required some warm-up time, and
that they had a tendency to flicker.
Still, there were enough researchers on the job to
ensure that eventually most problems would be resolved, and we would get a
fluorescent bulb that could screw into a standard socket. That happened in
1980, when Philips introduced a screw-in lamp with integral ballast, the
first compact fluorescent lamp (CFL). Osram
followed that in 1985 with the first CFL to include an electronic
ballast. These tube types remain the most popular in Europe, but in North
America, helical lamps , first released in 1995,
have become the favorites.
CFLs cost much more than standard incandescents
– and their price has shot up even more lately, due to their need for
rare-earth metals, whose cost has risen rapidly in recent years as they are
used in virtually every single type of electronic component. However, despite
cost struggles, they have a number of advantages. The primary one is energy
consumption. They convert far more electricity into light (measured in lumens
per watt), as you can see here:
In addition, CFLs have a life rated at some 10-20 times
longer than their rivals, at least when operated continuously, for several hours
at a time. Their light is more diffuse, reducing glare. And you can touch
them without getting burned.
Nevertheless, consumer response has been tepid, as
there are some major disadvantages. Many still don't like the light quality.
If there is frequent on/off switching, fluorescents age rapidly and their
life is severely shortened. The shape is not suitable for many lampshades.
They emit much more UV light than incandescent bulbs, which can affect
sensitive individuals and harm paintings. Some people may also be sensitive
to their flicker rate, and there's suspicion they can trigger migraines. They
can't be used with a dimmer switch. And the mercury they contain can be a
health hazard if they're broken.
It's this potential toxicity issue that has critics of
the conversion to fluorescents most up in arms.
The US government has mostly downplayed the mercury
risk. However, in Australia, they're considerably more cautious. Lengthy
guidelines for cleanup of a broken fluorescent include the following
windows and doors to allow the room to ventilate for 15 minutes; do not use a
vacuum cleaner or broom, instead scoop up broken material (e.g. using stiff
paper or cardboard), if possible into a glass container which can be sealed
with a metal lid; use disposable rubber gloves rather than bare hands; use a
disposable brush to carefully sweep up the pieces; and it is important to
emphasize that the transfer of the broken CFL and clean-up materials to an
outside rubbish bin (preferably sealed) as soon as possible is the most
effective way of reducing potential contamination of the indoor environment.
That's not even exhaustive and it’s already quite
Despite these differing viewpoints on the safety of
fluorescent bulbs, CFLs have to some extent become the battle flag of an
escalating political and economic war being waged against the incandescent
The Lighting Wars
It's doubtful that any of the pioneers of electric
lighting could have imagined their products becoming political footballs. But
never underestimate the capacity of the government to involve itself in every
possible aspect of life, including consumer choice.
Welcome to the lighting wars.
Governments around the world are moving to mandate the
demise of the incandescent bulb. Brazil and Venezuela started phasing them out in 2005. The European Union, Switzerland,
New Zealand, and Australia began their phase-outs in 2009, and others are on
track to do the same, including Argentina, Russia, India, and Canada this
The US government got into the act in December 2007,
with the passage of the Energy Independence and Security Act (EISA). Tucked
inside it was a requirement that all general-purpose light bulbs that produce
310–2,600 lumens be 30% more energy efficient than then-current
incandescent bulbs between 2012 and 2014, starting with standard 100-watt
bulbs and working down to 40-watt bulbs.
By 2020, a second tier of restrictions would become
effective, requiring all general-purpose bulbs to produce at least 45 lumens
per watt (similar to current CFLs). Exemptions from the Act include reflector
flood, three-way, candelabra, colored, appliance lamps, plant lights, stage
lighting, and other specialty bulbs.
Mostly, they want to force you to change the light
bulbs in your living room.
The near-term winner from all of this meddling thus far
has been the CFL. However, there are quite a few dark horses in the race to
fill the gap, and they're about to be thrust upon the market.
The Future of Light
The future is… well, bright.
What technology will ultimately come to dominate the
lighting market is still up for grabs, but in the near term, one possibility
is incandescents redux.
Once EISA was put in place, manufacturers of the traditional bulb tried any
number of ways to make it more efficient. The first bulb to emerge from this
push – Philips Lighting's Halogena Energy
Saver – uses a special chamber to reflect formerly wasted heat back to
the filament to provide additional lighting power. They're expensive, selling
for about $5 apiece. But they're cheaper than many fluorescents and are also
30% more efficient than standard bulbs, bringing them into EISA compliance.
Longer term, however, it's likely that both
fluorescents and incandescents will go the way of
One potential replacement is electron-stimulated
luminescence (ESL). It works through accelerated electrons hitting a phosphor
surface, making the bulb glow in a process known as "cathodoluminescence."
The process is similar to that employed by your old computer monitor's
cathode-ray tube (CRT). ESLs are mercury-free and have the same light quality
as incandescent lamps, but are about 70% more energy efficient, produce 50%
less heat, and are rated to last up to five times longer than incandescents.
The bulbs were developed by a small company, Vu1, and
are new to the market, so they're rather hard to find at the moment. If you
can locate one, a 65-watt equivalent will set you back about $20 – far
from a valid economic substitute for the few dollars a standard light bulb
will typically cost.
But the real challenger on the horizon is the LED
(light emitting diode). These little dots of light have become familiar to
many consumers because of their widespread use in automotive taillights and
more recently their appearance in flat screen TVs.
LEDs came out of electronics technology and are
semiconductor based. They stimulate electrons to release energy in the form
of photons, a process called "electroluminescence."
They have been around since the 1960s, so adapting them
to home lighting has taken some time. But the first commercial products are
on the way. They're also mercury-free, more energy efficient than incandescents, and dimmable. They don't degrade with
frequent on/off switching, and they're rated to last six times longer than
CFLs. Right now, they are just beginning to appear in the marketplace; their
main drawback is cost, about $20 apiece for a replacement bulb. Individual
LEDs are cheap, down to a few pennies apiece from hundreds of dollars in the
1970s. However, stringing together a set of them – with the wiring
required to make them work together and with a standard lighting socket
– still costs quite a few dollars. That seems likely to come down as
mass production sets in and the tech improves; thus many people have tabbed
them as the bulb of the future. And we have to say, the new Switch LED
bulb is nothing if not futuristic.
In truth, though, there's no telling what is going to
catch on in the end – after all, an LED bulb may be rated for 20 years
of life, but a lot of new innovation can happen over two decades. Something
better could easily come along even before the first LEDs start to burn out.
Holy Light Saber
Yes, it's just possible that one of those innovations
is going to be laser lighting.
The first step along that road, so to speak, has been
taken by BMW, which recently revealed that the company plans to outfit its
cars with laser headlights "within a few years."
If you're concerned about tooling down the highway and
suddenly getting blasted by a laser that burns your retinas, BMW says,
"Don't be." The bluish laser beam isn't emitted directly, but is
first converted by means of a fluorescent phosphor material inside the
headlight into a pure white light that is suitable for use in road traffic
and poses no risk to humans or animals. The emitted light would also be very
bright and white, making it more comfortable to the eye.
Because it is a "coherent" light source, BMW
says that laser lighting can produce a near-parallel beam with an intensity
that is a thousand times greater than LEDs. At the same time, it requires
only half the energy of LED headlights. Where LED lighting generates about
100 lumens per watt, the laser would generate around 170 lumens.
The diodes used in a laser light are also small, about
10 microns in length – far shorter than the one-millimeter-long,
square-shaped cells used in LED lighting. This means that BMW could radically
reduce the size of its headlights. The company says it has no plans to do so,
but this raises some intriguing possibilities.
One can envision the day when a home or office is
illuminated by a few tiny lights that consume almost no energy at all.
Now there's a prospect that should please both
consumers and meddlesome bureaucrats.
To profit from exciting 21st-century
breakthroughs like revolutionary new forms of lighting, you must avoid these three technology-investing myths.]