Despite plenty of technical advances, incandescent lightbulbs still rule when it comes to color and quality of light. The trouble is, they don’t always last so long, and they waste almost all of their energy, emitting it as heat.
But what if you could have the color of incandescents, with the efficiency of an LED? That’s the promise of new research out of MIT. The new bulb works by arraying nano-mirrors around a regular incandescent element, reflecting the wasted heat back into the element. This brings incandescents into the efficiency range of LED and fluorescent bulbs.
Incandescent bulbs look so good because they emit all colors of light, whereas LEDs and other more efficient light sources only manage a subset of all the colors of visible light. If you look at the color-range emitted by some energy-saving bulbs, chinks of the spectrum are missing. Our eye adjusts, but like digitized music compared to tape or vinyl, the brain may still subconsciously notice those gaps. This “full-spectrum” light also means incandescents are better than anything else at rendering colored objects faithfully. They’re like tiny little suns, only yellower (although the yellow tint has nothing to do with the “full-spectrum” aspect).
Published this week in Nature, the paper details the method. The bulb’s element is surrounded by a “cold-side nano-photonic interference system,” essentially a mirror which lets visible light pass but reflects infrared heat. This heat is then reabsorbed by the element, causing it to emit more light. It’s a clever trick, and in principle very simple. To make the lamp, the tungsten element itself was modified too–the MIT bulb uses a ribbon instead of a strand, which is better for soaking up that reflected heat.
The experiment, carried out by physicists Ognjen Ilic, Marin Soljačić, and John Joannopoulos, managed to triple the efficiency of an incandescent bulb to 6.6%. The team thinks it could refine the setup to reach 40% efficiency, which is at the upper limit possible for any light source. An LED maxes out at 15% efficiency.
If the process of layering up the nano-mirrors can itself be made efficient enough for cheap manufacture, we could be back in business. You will be able to relax in your home, listening to your analog vinyl records and enjoying the prints made from your film camera in the full-spectrum, perfectly color-rendered light of an incandescent bulb, all without destroying the planet. It sounds like hipster heaven.
Can you still buy incandescent light bulbs?
The short answer is yes.
In spite of some bad reporting a few years back, the government did not ban light bulbs using incandescent lighting technology.
The reality is manufacturers had to stop making any lamp that failed to meet the energy standards outlined by EISA. Those lamps were, for the most part, tungsten-filament incandescent bulbs.
An FAQs document put out by Energy Star in 2011 explained the new light bulb manufacturing restrictions in this way:
“The standards are technology neutral, which means any type of bulb can be sold as long as it meets the efficiency requirements. Common household light bulbs that traditionally use between 40 and 100 watts will use at least 27% less energy by 2014.”
Manufacturers stepped up to the challenge. Today’s incandescent light bulbs are, on average, doubly as efficient as they were when EISA was signed into law. Some of this is thanks to advancement in halogen technology — part of the incandescent family.
That brings us to today. We know the next round of restrictions outlined in EISA will not happen in 2020, but that doesn’t stop them from going into effect at some point.
State and municipalities are also starting to implement their own restrictions. For example, California moved forward with the proposed 2020 EISA restrictions in 2018. As we mentioned, the state will also move ahead with further restrictions starting January 1, 2020.
In the meantime, most light bulbs are well beyond minimum energy efficiency requirements, especially CFLs (compact fluorescent lamps) and LEDs.
What incandescent bulbs are still available?
If you visit the incandescent section of our online store, we have more than 600 incandescent light bulbs for sale. Obviously, there is no shortage.
Here is the difference: the incandescent light bulbs available for purchase today have wattages reduced by about 30 percent, but with a similar light output (lumens in technical lighting terms).
For example, the equivalent of an old 60-watt A19 incandescent uses 43 watts, on average. The equivalent of a 100-watt A19 incandescent, meanwhile, uses 72 watts for the same lumen output.
There are a couple of caveats that should be noted here. For one, some aren’t happy with the light color (or color temperature) of modern-day halogen-based incandescent bulbs, as halogen tends to emit cooler colors. Pre-EISA incandescent bulbs might have had a Kelvin temperature of 2400K or 2700K while today’s incandescent bulbs will often have a color of 3000+ K.
Secondly, as mentioned above, there are a few exceptions, or loopholes, in the EISA-standard incandescent bulbs. Light bulbs for certain applications — like heat lamps, for example — do not need to meet the new standards.
Incandescent bulbs vs. CFLs
Compact fluorescent lamps (CFLs) were the first lamps to really barge into the market and gain a foothold against incandescent light bulbs. They’ve always been much more energy efficient but have a handful of cons that most businesses and consumers like to weigh into their decision-making process.
- CFLs contain mercury – a toxic metal which is bad for the environment and people. This means they must be recycled properly.
- A lot of CFLs don’t dim, making them incompatible with dimmable fixtures you might have in your building or home.
- When compared with an incandescent, the color rendering index (CRI) of a CFL is quite limited.
- Many CFLs come in a spiral shape, causing a lot of people to opt for a traditional bulb-shaped lamp to preserve certain aesthetics.
Comparing average household lamps – Incandescent vs. CFL
|Old incandescent||New (halogen) incandescent||CFL|
|Lumens (light output)||780||780||780|
|Wattage (energy usage)||60||42||10|
|Lumens per watt||13||18.5||78|
Incandescent bulbs vs. LEDs
LEDs continue to carve out a bigger territory in the lighting world. A significant part of that trend is tied to the technology’s drop in price, making them immensely more competitive. The other part of that? Energy efficiency, of course. The long lifespans of LEDs combined with their incredibly low energy usage rate give them a corner on the energy efficient lighting market. There is simply no comparison to LEDs in terms of energy efficiency alone.
But if you’re familiar with the calling card of LEDs — energy efficiency — you’re probably equally as familiar with their Achilles heel: cost. LEDs used to cost as much as 40 times more than modern incandescent light bulbs. But, as mentioned above, they’ve come down in price big time.
Today’s LEDs are maybe five or seven times more expensive than a comparably bright incandescent. But the flip-side of this is the massive energy savings. In most cases, LED light bulbs pay for themselves in a matter of months when replacing LEDs.
Comparing average household lamps – Incandescent vs. LED
|Old incandescent||New (halogen) incandescent||LED|
|Lumens (light output)||780||780||780|
|Wattage (energy usage)||60||42||5|
|Lumens per watt||13||18.5||156|
*LEDs greatly vary in price and features. The above price reflects a middle-of-the-road 60 W-equivalent LED lamp.
Questions about incandescent light bulbs
There you have it – all the facts.
Were all incandescent bulbs strictly banned by the federal government? No, they were made dramatically more energy efficient (unless you live in California).
Are incandescent bulbs on the verge of being pushed out of the market? It depends on the next set of regulations.