The smart light bulbs of the future are supposed to light up more quickly, reduce energy usage and, ultimately, save you money.
But according to a study by scientists at the University of Wisconsin-Madison, it’s not so simple.
A report published online in the journal Energy Policy and Management by a team of researchers at the UW-Madison and the University at Buffalo found that while the smart bulb industry has been improving the efficiency of its products, the bulbs that are supposed by law to light more quickly are actually getting worse.
“The bulb has to be really light, because light does not flow in the same way as it does for a regular light bulb,” says Robert Pender, a UW-Milwaukee physicist who co-authored the study.
“So what you have is a bulb that is very inefficient, because the amount of energy it consumes is much higher than the amount that it uses.”
“The bulbs have to be very light, for light to flow in” the same sense as it flows for a normal light bulb.
The light bulbs used in smart lighting are made from two types of materials: silicon and carbon nanotubes.
But the UW’s study suggests that while these materials are “very light”, the silicon and the carbon nanomaterials are actually less efficient than the materials used in traditional light bulbs.
“They’re not as light-dense, they’re not very light-efficient, they don’t generate much heat,” Pender says.
“It’s a big question mark.
The technology has advanced so quickly that we don’t know what it will look like when we get to the consumer.”
So how are smart lights actually making it through the energy-consuming life of a light bulb?
According to the study, the smart lightbulb industry has developed a new material that is less energy-efficient than silicon and more energy-intensive than carbon nanorods.
It’s called PTFE, for PTF-free carbon-nanotube alloy.
PTF is used in a variety of products including smart bulbs, video-game consoles, light fixtures and the solar panels on solar panels.
“This is a new class of material,” says Pender.
“PTFE is a material that’s very light because of the high amount of carbon it contains.
So the amount you can use in a lightbulbs is very small.”
The study showed that the energy consumed by a light bulbs made from PTFEs is significantly less than that of an equivalent product made from silicon and then coated with carbon nanodiamonds.
“You’re looking at a difference of about 10 per cent,” Penders co-author Peter K. Ritter, professor of materials science and engineering at the university, says.
The result is that PTFe is actually 20 per cent less efficient at converting light into electricity than silicon.
But in reality, it actually only represents 10 per per cent of the light emitted by a standard smart light, which has a bulb made from a mix of silicon and PTF.
“When you think about the energy efficiency of a standard bulb, it looks like the energy consumption of a typical bulb is about 80 per cent, but in reality it’s a little less than 20 per in a standard LED bulb,” Pinder says.
Pender is not the only one to question the reliability of PTFs.
The UW researchers tested a variety types of smart light and found that PBF is not only less efficient, but it has a number of additional problems.
One problem is that it can be very brittle and not easily replaced.
“What happens when it breaks?
That’s the big one,” Pnder says.
Another issue is that its structure can degrade over time.
The researchers tested different PTF compounds and found they all had different fracture-rate characteristics.
The best ones, such as PTF E200, are not only stronger than PTF, but they also have higher fracture-rates than PBF.
These factors combined make PTF a material which is not suitable for high-efficiency LED lighting.
“If we look at the future, the most energy-effective LED light bulbs will be those that use PTF for light efficiency, because we have this problem of a high fracture-recovery ratio,” Pinner says.
According to Pender and Ritter’s paper, the new PTF alloy is not going to replace the silicon bulb market, but rather, it may even be used in light bulbs for use in high-energy-efficiency lighting, which will be an important market for the smart-light industry.
Pinder is hopeful that future smart bulbs will replace silicon bulbs, but admits that there is a lot of work to be done before the next generation of smart bulbs are available.
“We’re looking forward to the day that we can say, ‘Oh, well, this technology has been around for a long time,'” he says.