ECO WARRIOR
LEDs – from cradle to grave

The manufacture of LEDs and their disposal comes under the Eco warrior’s steely gaze. By Kevan Shaw, design director at KSLD

A couple of interesting things have crossed my desk this week. The first is a paper by Seong-Rin Lim et al on the potential environmental impact of LEDs. The other is Nigel Harvey’s article in Lux discussing the sourcing of rare earth metals.

The paper is a basic look at the potential waste toxicity of LEDs at end-of-life disposal. This is the first paper I have seen on this subject, but it does have its limitations. The study looks at 5mm indicator-type LEDs rather than the higher power lighting devices. It also discounts the impact of the encapsulating medium that forms the bulk by weight and volume of these devices. Nor does it take into account the effect of this packaging in preventing materials entering the biosphere.

Obviously this leaves a big field open for further research looking at lighting LEDs in large high power packages and SMD devices that do not have the encapsulation of a 5mm device. The conclusions are that there is very little impact from well-known pollutants such as lead, copper, gold, silver and arsenic – all of which are present in other light source technologies.

Joining the waste stream

Given the methods used to ‘recycle’ waste electrical and electronic equipment – and that includes lighting equipment – the opportunities to separate out the LED elements are generally non-existent. This paper suggests that there really is no purpose to be served in separating the elements on grounds of contaminating other parts of the waste stream.

I would, however, question how we should be dealing with LED lighting equipment that will in many – if not most – cases not be end-of-life when we come across it during refurbishment projects in the next several years. Of course, the newer available technology will be more energy efficient, but will the overall environmental impact, including embodied energy and use of resources, have been amortised during the period between installation and removal?

The article by Nigel Harvey flags up the issue of rare earth metal supply, particularly for phosphors. Currently the majority of this material is won in China. Never a country to miss an opportunity to establish its place in the market, China has now restricted export of these materials, but not on the export of finished or semi-finished products that use these materials. So guess where the majority of white LEDs are going to be made?

This is going to have a significant impact on other Asian countries such as Korea, Malaysia and Taiwan that have made big strides in LED manufacturing in the past decade. Now companies are being forced to move their entire manufacturing or packaging to China. Cree has just announced its first LED factory in mainland China, hot on the heels of various Taiwanese and Korean companies. Meanwhile sales of the reactors (non-nuclear) used to coat the LED material onto the disks of substrate have gone through the roof to new Chinese start-ups jumping on the LED bandwagon.

It seems China is set to corner the LED market in the same way that it has become the world’s dominant supplier of compact fluorescent lamps.

www.ksld.com

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