• The world has been shifting away from wasteful incandescent and harmful fluorescent lights and increasingly adopting light-emitting diode (LED) technology, which promises to reduce carbon emissions.
• Yet despite widespread adoption of the technology, virtually no LEDs are currently recycled or reused for their parts.
• To counter this problem, researchers are exploring ways in which LEDs can be designed for reuse and repair, as well as improving the efficiency of recycling.

The past decade has seen a paradigm shift in the way the world looks at lighting. Homes, offices and streets have turned off wasteful incandescent lights and fluorescent ones that exposed users and the environment to toxic contamination.

In their place, climate scientists and governments have promoted light-emitting diode (LED) bulbs to tackle ballooning electricity consumption, of which about 20% is from lighting, making up 6% of global carbon emissions. Without the adoption of LEDs, global energy consumption for lighting could swell 60%  by 2030.

Thanks to the use of the material gallium nitride, which produces blue light and won its inventors the Nobel Prize in Physics, LEDs use roughly 75% less electricity and last 25 times longer than previous forms of lighting.

“Blue LEDs are fantastically efficient,” says Rachel Oliver, a professor of materials science at the University of Cambridge. In 2017, analysts at IHS Markit, a climate information service, said the switch to LEDs was responsible for a reduction in emissions of half a billion tons of CO₂ that year — equivalent to shutting down 162 coal-fired power plants.

Thanks to the use of the material gallium nitride, which produces blue light, LEDs use roughly 75% less electricity and last 25 times longer than previous forms of lighting. Image by Bill Bradford via Flickr (CC BY 2.0).

LEDs constitute over half of light sales around the world, according to the International Energy Agency, which puts lighting on track for hitting its net-zero scenarios by 2030. That also leaves a lot of room for growth. On top of that, people and businesses are using more lighting than ever before, so the technology chosen to illuminate society will likely need to be rolled out in much greater numbers than what currently exists. Speed is also important, as the IEA estimates that a net-zero scenario depends on LEDs accounting for all lighting sales by 2025.

Despite widespread adoption of the technology, around the world, virtually no LEDs are recycled or reused for their parts. Most of the development of LED lights takes place behind closed doors and researchers have been surprised to discover which materials end up in the lights they buy.

The road ahead for the LEDs will be shaped by the ability to engineer lights that are suitable for recycling, to make them last as long as possible and to reduce the harmful effects that light pollution has on human health and ecosystems. Finding the materials necessary to produce them could make companies rethink both mine waste and post-consumer waste.

“Gallium nitride is a very good material for making very efficient lights, and we want very efficient lights because that is a good way of reducing carbon costs,” says Oliver, who also directs the Cambridge Centre for Gallium Nitride. “So how do we make them live longer so we don’t have to use as many? And how do we make them so that they are designed for recyclability from the start?”

People and businesses are using more lighting than ever before, so the technology chosen to illuminate society will likely …….

Source: https://news.google.com/__i/rss/rd/articles/CBMiW2h0dHBzOi8vbmV3cy5tb25nYWJheS5jb20vMjAyMi8xMS9sZWQtbGlnaHRzLWNvdWxkLWNvbnRyaWJ1dGUtdG8tbWFzc2l2ZS1jYXJib24tcmVkdWN0aW9ucy_SAQA?oc=5