Three researchers at MIT have invented an incandescent light bulb with an energy efficiency performance very close to the LEDs bulbs thanks to the nanotechnology implementation. They developed a so called light recycling approach. It’s basically a two-stage process: first step we have a conventional heated metal filament, with all its attendant losses. But instead of allowing the waste heat to dissipate in the form of infrared radiation, secondary structures surrounding the filament capture this radiation and reflect it back to the filament to be re-absorbed and re-emitted as visible light. These structures, a form of photonic crystal, are made of Earth-abundant elements and can be made using conventional material-deposition technology.
The final performance assessment points out that the new two-stage incandescents could reach luminous efficiencies as high as 40 percent, while a conventional incandescent light bulb scores between 2 and 3 percent, CFLs devices score between 7 and 15 percent, and most commercial LEDs have a 5 to 20 percent efficiency.
The market pays attention to the news that could really reshape the current situation. Despite the fact that incandescent bulbs are considered obsolete by most observers, many consumers remain quite oriented to this kind of product because of the warm light spectrum they produce. It’s due to the waste of energy used to produce infrared emissions and thermal effect, but it’s still a concrete difference while considering the different products available on sale. The global real value of sales for the light sources increased by +13% in the last five years with an overall value of aprox USD 20 billion, and a quick fall (-68%) for the incandescent bulbs market being phased out by CFL and LED products now dominating the sales.
MIT professors point out that the materials needed for their prototype are relatively abundant in nature and cheap, so the manufacturing process is scalable and could lead to a market ready device very soon. Despite that we wouldn’t expect any revolution in the market, because the new products would be unlikely slowing the decline of incandescent lamps. The cost of producing nanomaterials remains very high, and it’s not expected to be cut in the next 5-10 years. It’s already a sufficient mid term period to allow CFL and LED products to finally win the battle on the incandescent bulbs, even on those customers still fond on the traditional products.