Even though most traditional incandescent bulbs aren't being manufactured anymore, the lightbulb wars are far from over. If the comments on our last article about choosing a lightbulb are any indication, many people aren't thrilled with the CFL and LED alternatives on the market.
It is true that even with advances in CFL and LED technology, incandescent bulbs still strike the best balance of cost, light quality and longevity. Unfortunately, they have terrible energy efficiency, which is what the government is regulating. However, researchers at MIT have found a novel way to boost the efficiency of incandescent lightbulbs.
As you probably know, incandescent bulbs create light by heating a tungsten filament to temperatures of 2,700K or higher. According to MIT, this process uses only 2% to 3% of the electricity for light and the rest is wasted as heat. CFL bulbs can manage 7% to 15% efficiency and LEDs range from 5% to 20%.
In a novel approach, MIT figured out a method of "light recycling" to turn incandescent waste heat back into light. Specifically, it coats the bulb with finely tuned photonic crystals that let light pass through but not infrared radiation (heat). The heat is reflected back into the filament to help keep it at light-producing temperatures.
In the first tests, MIT managed to get the incandescent efficiency up to 6.6%, which matches low-end LEDs. However, it says that with more fine tuning it might bring the efficiency up to 40%, or double the most efficient LEDs.
The manufacturing process for these bulbs doesn't seem too tricky. It just remains to be seen if MIT really can improve the efficiency as much as it claims, and if lighting manufacturers want to jump on board.
Given that the government has another round of regulation scheduled in the coming years that will require bulbs to meet even higher efficiency standards, these ultra-efficient incandescent bulbs might be the future of lighting.