the evolution of the light bulb

The humble light bulb has been around so long that it feels a bit strange to discuss it in the realm of eco-tech. We forget that the light bulb, now found in virtually every single home in America, was once a groundbreaking innovation. Light! At the flick of a switch! Prior to this invention, candles or lanterns were the only way to see after the sun went down. Both posed serious fire hazards and illuminated only the small area around them. Light bulbs changed everything.

‘Just’ one little light bulb

sketch of light bulb
Invented by Edison in 1879, the incandescent light bulb could instantly transform any space with light as bright as day. Image Credit: THPStock / Shutterstock

Invented by Edison in 1879, the incandescent light bulb could instantly transform any space with light as bright as day. This simple invention has been credited (and blamed) for stretching the length of work days, tampering with our circadian rhythms and, within the last few years, wasting an incredible amount of energy.

The issue behind the wasted energy can be found in Edison’s simple design. An incandescent bulb works by using electricity to heat up a thin wire inside the bulb to a temperature hot enough that it begins to glow and emit light. This is how the bulb creates light, but it also creates a ton of excess heat – in fact, 95% of the energy used by the bulb is wasted, mostly by creating this heat, not the light we’re looking for.

That’s so 2000

CFL bulbs gained popularity in the early 2000’s and quickly replaced the old standby incandescent bulb. They cost more to purchase but one CFL bulb typically saves consumers over $30 in energy costs during its use. More recently, LED bulbs have increased in use because they offer virtually identical energy savings as CFL bulbs, but without the small amounts of mercury. Although the mercury in CFL bulbs remains sealed within the bulb while in use, it can become exposed if the bulb breaks.

For a while the lowly incandescent bulb seemed destined to follow in the footsteps of the rotary phone or dial-up internet – an archaic form of tech designed for museums and those too stubborn to change. A recent innovation by MIT researchers may just put the incandescent bulb at the forefront of eco-tech, back in the running for energy efficient lighting – and back on store shelves, too.

A cool idea, seriously!

The key to transforming this energy-wasting light bulb into incredibly efficient eco-tech lies in developing a way to capture all of that heat generated (and lost) by heating the wire. A report in Science Daily describes the groundbreaking design of the incandescent light bulb 2.0 :

“The researchers create a structure that surrounds the filament. This structure, made from a form of photonic crystal, captures the excess radiation produced by the wire and reflects it back to the filament, where it becomes re-absorbed and re-emitted as visible light.”

Being able to capture this wasted heat energy and feed it back into the filament means that the bulb is able to recycle its own waste product to generate light. The goal is creating as close to a closed loop system as possible, wasting little to no energy.

Nanophotonic interference

The challenge for researchers in creating this bulb was finding a material that would be able to capture the energy but also be able to allow the light from the filament to pass through it. They achieved this by creating a nanophotonic interference system, which is exactly as Star Trek-ish as it sounds. The result is a bulb that looks like the old familiar incandescent (with it’s warm, pleasant glow) but with energy efficiency rapidly approaching that of CFL and LED bulbs. With continued development, researchers hope that this new bulb could one day triple the energy efficiency of our most eco-friendly bulbs today.

The new incandescent bulb isn’t available for purchase yet. Researchers are still working to get efficiency levels to meet those high targets, and ensure that this new reboot of an old favorite gives consumers an added energy savings over the “energy efficient” CFL and LED bulbs found so commonly now.  But in addition to the energy savings, I think we all have another big reason to look forward to this newest development in eco-tech.

You’re glowing

CFL light bulb
The CFL light bulb, like other lighting, has its share of critics and champions. Image Credit: Looker_Studio / Shutterstock

The focus of much of the excitement about this energy efficient incandescent bulb is the amount of energy used, and the innovative technology that helped reduce that energy use to a fraction of what it once was. But I can’t be the only one who is desperately looking forward to ditching those cold, stark CFL bulbs for something a little warmer. Every so often I find a “soft white” CFL bulb that actually lives up to its name and casts a warm glow instead of lighting up my living room like a hospital cafeteria, but the bulbs last so darn long that I inevitably forget which one is the good kind when it comes time to replace it.

Purchasing the wrong kind of CFL bulb means suffering through years of cold light that reveals every little spot of redness, wrinkle or imperfection. This sort of terrible lighting could really take its toll on the fragile ego of a neurotic writer as she rapidly approaches the aesthetic quagmire of her mid-thirties! Um…hypothetically speaking, for example.

So keep your eyes out for the new-old incandescents. Offering energy savings, increased efficiency over CFL and LED bulbs, and a gorgeous warm glow that lights up a room like candlelight, they’re a fresh new spin on old eco-tech. And when they hit stores I can guarantee you I’ll be the first in line. Because of the efficiency, of course.

Feature image credit: Vladimir Gjorgiev / Shutterstock

By Madeleine Somerville

Madeleine Somerville is the author of All You Need Is Less: An Eco-Friendly Guide to Guilt-Free Green Living and Stress-Free Simplicity. She is a writer, wannabe hippie and lover of soft cheeses. She lives in Edmonton, Canada, with her daughter. You can also find Madeleine at her blog, Sweet Madeleine.