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Scientists Build a Better Incandescent Light Bulb… Six Years After Last US Factory Closes

Barbara Hollingsworth
By Barbara Hollingsworth | April 22, 2016 | 10:50 AM EDT

Protoytpe of a new energy efficient incandescent light bulb. (Massachusetts Institute of Technology)

Six years after the last incandescent light bulb factory in the U.S. shut down due to strict new federal energy conservation standards, scientists at the Massachusetts Institute of Technology (MIT) have come up with a technological breakthrough that could make incandescent bulbs twice as energy-efficient as their replacements.

MIT researchers discovered that by wrapping the filament of an incandescent bulb with a “photonic crystal,” they could “recycle” the energy that was typically lost as heat to create more light.

The new technique “makes a dramatic difference in how efficiently the system converts electricity into light,” said the research team led by MIT professors Marin Soljačić, John Joannopoulos and Gang Chen.  

Their results were published online in the January edition of the journal Nature Nanotechnology.

“The heat just keeps bouncing back in toward the filament until it finally ends up as visible light,” MIT post-doctoral researcher Ognjen Ilic explained. “It reduces the energy that would otherwise be wasted.”

In 2007, Congress passed the Energy Independence and Security Act, which set new energy conservation standards for lighting fixtures and other products by 2014 in order to reduce energy use and greenhouse gas emissions.

The “new light bulb law”, as it was called, required “25 percent greater efficiency for household light bulbs that have traditionally used between 40 and 100 watts of electricity,” according to the Environmental Protection Agency (EPA).

The stringent new standards effectively prohibited the manufacture of most ordinary incandescent light bulbs in the U.S. As a result, GE shuttered the last domestic incandescent light bulb factory in the nation in 2010, laying off 200 workers in Winchester, Virginia.

Since then, incandescent bulbs have been largely replaced with more energy-efficient compact fluorescent lights (CFLs) and light-emitting diode (LED) lamps. In February, GE announced that due to poor sales, it would no longer make or sell CFLs – which contain mercury - in the U.S., and will focus on the more expensive, but longer lasting LEDs instead.

But a new generation of incandescent bulbs could be twice as energy efficient as LEDs without the drawbacks, including higher initial cost and “inconsistent” white light.

“Whereas the luminous efficiency of conventional incandescent lights is between 2 and 3 percent, that of fluorescents (including CFLs) is between 7 and 15 percent, and that of most commercial LEDs between 5 and 20 percent, the new two-stage incandescents could reach efficiencies as high as 40 percent,” according to a press release from MIT.

The MIT researchers noted that the greater increase in energy efficiency also comes with “exceptional reproduction of colours and scalable power.”

In February, Rep. Michael Burgess (R-TX) introduced the Energy Efficiency Free Market Act of 2016 (HR 4504), which would prohibit states and federal agencies from adopting “any requirement to comply with a standard for energy conservation or water efficiency with respect to a product.”

“This legislation eliminates the overreaching arm of the federal government that continues to force itself into the household of the American consumer,” Burgess said. “When the market drives the standard, there’s no limit to how rapidly manufacturers can respond when consumers demand more efficient and better-made products.”

According to the Energy Information Administration (EIA), commercial and residential users in the U.S. used 412 billion kilowatthours of electricity for lighting in 2014. Lighting accounted for 15 percent of their total electricity use.

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