Engineers at GE’s NELA Park in East Cleveland, Ohio, have spent a century building better light bulbs. When NELA opened in 1911, it became the world’s first industrial park, a distinction that earned it a place on the National Register of Historic Places. But now a new kind of history is taking place at NELA, the kind that will soon dispatch the incandescent light bulb down the same road traveled by the LP and the VCR. “This is an evolution,” says Glenn Kuenzler, a lighting engineer at NELA. He and his team of researchers are making sure that the GE bulb, whose legacy stretches back to Edison, is fit to survive.
Kuenzler’s team has developed a new LED bulb that looks and shines like the 100-watt incandescent workhorse likely burning in your kitchen, but consumes less than one third of the power and lasts 25,000 hours, or over 22 years, if turned on 3 hours per day. “We first thought about it three years ago,” Kuenzler says. “But it was not technically achievable.”
Those are challenging words to any curious engineer. Kuenzler’s team spent a few years working out the hurdles and checking out available technology. In June 2011 they started on the new LED bulb.
Kuenzler’s chief nemesis was heat. Though LEDs need a fraction of the power consumed by the incandescent bulb, the 27 watts that run the new bulb still make the LEDs inside so hot they could boil a cup of tea. LEDs are made from silicon, just like the semi-conductor chips inside your computer. Without cooling, they will burn up.
Kuenzler and his team searched for the right device to keep the heat down. A tiny fan, perhaps? “We wanted to meet people’s expectations and make the bulb last 25,000 hours,” Kuenzler says. “That means that every component for the bulb has to last at least that long.” But the best fans are very expensive and fail after 15,000 hours.
Another device called synthetic jet, or synjet, looked promising. Developed by the ecomagination Challenge winner Nuventix, it works like a pair of tiny vibrating sub-woofer speakers mounted back to back. The vibrations push hot air away from the LEDs and the device lasts as long as 100,000 hours. There was one problem. “It was the size of a puck,” Kuenzler says. “There was no way it would fit inside the bulb. There wouldn’t be any room for anything else.”
The whole process was like building a ship inside a bottle, but they shrunk the synjet and moved on the next challenge: the light itself. Unlike tungsten filaments inside regular light bulbs which glow evenly in every direction, LEDs shine straight ahead. “We had to bend the light,” Kuenzler says. The team developed special optics that send light around the synjet and other components, and make it shine like a light bulb. “If the cooling blocks the light, you don’t have a bulb,” Kuenzler says.
The team went through seven designs in nine months before they had a winner in early spring 2012. The work fetched a number of patent applications. GE Lighting is planning to move the LED bulb to production early next year.
With the engineering work done, it’s now on to education. “The whole market has been conditioned to understand light from the perspective of watts,” Kuenzler says. “But people don’t really want to use 100 watts, they want 1,600 lumens of light,” he says, the light output of a standard 100-watt incandescent light bulb. The new LED is set to make strides in changing that old mindset.