Fast Company staff writer John Brownlee takes a closer look at a new, MIT-developed incandescent bulb that claims to be as efficient as an LED equivalent by bouncing heat back at its filament. This keeps the filament hotter while simultaneously using less electricity.
The innovation aims to appease consumers that are hesitate to switch to LEDs, preferring the warm and homey—albeit less energy-efficient—glow of an incandescent. Though it's not quite ready for release yet, MIT's design uses photonic crystals to reflect infrared light back at its filament, tripling the efficiency of a standard incandescent bulb.
Incandescent bulbs work by using electricity to heat up a thin tungsten filament—that little hair of metal you see inside every bulb—to more than 5,000 degrees Fahrenheit. The problem with this approach is that most of that electricity is wasted as heat, which is why a 60 watt incandescent light bulb emits the same amount of light as a 12 watt LED... So how do you make an incandescent bulb as efficient as an LED? Basically, you bounce the wasted heat back at the filament, so it stays hotter with less electricity.