Sustainability of LED production?

Question

Not all LEDs are the same. Standard LEDs use various combinations of indium, gallium, arsenic, silicon, phosphorus, zinc, selenium, and a couple other elements. Most of these need to be mined from the earth. Organic LEDs sound at first like they might be better, but they are only organic in the sense of "organic chemistry," not "grown without pesticides." However, in addition to organic compounds they also use indium, tin, barium, calcium, and aluminum so mining is still necessary.

Are there any LED technologies that avoid depleting limited mineral resources either by using only abundant materials or by being fully recyclable? Failing that, are there any LED technologies that are clearly more sustainable to produce than the others in terms of resources and environmental impact? Or do all LEDs effectively have equal impact and only differ in performance?

Answer 1

I think this is a great example of how sustainability really is multi-faceted. LED lighting may be great from an energy consumption standpoint, and not as good with respect to finite material usage.

Energy Use vs Material Supply

I think it's important, however, to apply some weighting to the different factors. I don't believe we're yet at a critical point with respect to rare earth material supply, but I believe we are already at a critical point with respect to climate change (primarily, that we have already passed the 350 ppm CO₂ threshold that many climate scientists believe is necessary to preserve the climate that humans have flourished in). So, in my opinion, it would be poor strategy to pass up energy-saving technologies in favor of technologies that save raw materials that we aren't running out of yet.

Light bulbs are unique devices, because they're small, but use lots of energy over their lifetimes. Their relative material footprint isn't that big, compared to their energy footprint. LED lights are expensive to produce, and use much more scarce material than incandescent bulbs, but they last for years (or decades).

LED lights are already the most energy efficient lighting solution available for most residential applications, and there is good reason to think they'll soon pass compact fluorescents by a significant margin.

Short Term Supply Constraints

Here is a report on GE's website about rare earth supply constraints. It's important to note, however, that current price spikes in these materials are largely an economic phenomenon. 95% of these materials are currently supplied by China, because China's policy is heavily influenced by engineers who saw this trend coming. China is also imposing export quotas. There are significant rare earth material reserves in the US (e.g. Nevada) and Australia, but the higher cost of labor here/there hasn't yet convinced those countries' companies or governments to ramp up production. It also takes years to bring new mines online. So, I would expect in the future, as climate problems worsen, and China's economy surpasses that of the US, this supply limitation will ease. Whether it will ease enough to satisfy increased demand requires a crystal ball (also a rare earth material).

Recycling

Another issue sometimes brought up is recylability. It's important not to assume that because a material isn't currently recycled, it's not recyclable. This assumption is made repeatedly with electric car batteries. Until products like LED lights are getting disposed of in large numbers, economic factors limit the opportunities for recycling them. That's not a long-term problem though, if LED lights (and other rare earth applications) catch on.

Long Term

Keep in mind that the theoretical potential for renewable energy is enormous. Just between solar and wind power, there is thousands of times more energy hitting the earth than we need (and even the harvestable potential is much more than we need). We're just not harvesting much of it now, in favor of consuming ten million year old sunlight stored in fossil fuels. But, in the long term future, we may be able to (once again) use technologies that use more energy, if the energy is renewable. At that point, we may decide to reduce, or reinvent LED lighting. But for now, I think the large energy saving potential of LED lighting makes it a good medium term (0 - 50 years) sustainability choice.

Answer 2

Its been many years since this question was asked, technology has developed, newer LEDs are far more efficient than LEDs from a decade ago. The control technology powering LEDs has also become far more efficient.

This introduces complications in estimating the sustainability of LED lighting. If you take a snapshot of LED technology in 2010, and asked how long can we go on like this, manufacturing the same LEDs in the same quantities, you might get an answer like fifty years.

But if you took a snapshot of 2019 LED technology and asked how long can we go on make the same quantities as 2010, you might get an answer like two hundred years.

But additionally as LEDs have become more efficient, they're also cheaper and so demand for them has increased, so you might only have the resources to build 2019 technology LEDs for a hundred years.

Since the efficiency, price and size of LEDs keeps improving and becoming broadly more sustainable, then the question is perhaps about limits.

In 1997 the UK reached 'Peak light bulb', since then the amount of energy required for lighting has reduced as consumers changed from incandescent lighting to more efficient technologies. In this respect lighting is now generally sustainable.

The old-fashioned incandescent light bulb was in production for over 150 years, the great leaps in efficiency were mostly in the first few decades of production, and by 1997, it couldn't be manufactured any more efficiently, it had reached its technological optimum.

LED lighting is still making leaps in efficiency and sustainability and will continue to for a few more decades. At each leap it is more sustainable than it ever has been, using smaller quantities of the limited mineral materials.