Thursday, January 24, 2013

Low Energy Light Bulbs Not So "Green" After All?

Making choices about the kind of light bulbs we should be using, on the simple basis of energy consumption, and hence carbon emissions, may be a little short-sighted. Thus, the old fashioned incandescent bulbs are no longer commonly on sale, though there is something of a black market in them, due to the poorer quality of light given out by their alternatives - low-power CFLs (compact fluorescent light bulbs) and LEDs (light emitting diodes).

The first incandescent (filament) bulb was invented by Joseph Swan, who gave the first public demonstration of the device at a lecture in Newcastle upon Tyne, in the north east of England, on 18 December 1878. Swan later illuminated his house, in neighbouring Gateshead, by means of the technology. Credit for the incandescent bulb is often, but incorrectly, given to Thomas Edison, who invented it independently, but later than Swan. In 1881, the Savoy Theatre in London was lit by Swan incandescent light bulbs; the first theatre and the first public building in the world to be lit entirely by electrical power. The basic principle of the incandescent bulb has changed little in the past 135 years, of which the main criticism is that most of the energy consumed by the bulb is discarded as heat, rather than providing useful light.

Despite the wide, and almost exclusive, adoption of CFLs and LEDs in place of the original design, a life-cycle analysis has shown that there may be an environmental legacy, beyond carbon emissions, or their reduction, in the form of toxic metals, especially copper, lead, mercury and zinc, with smaller amounts of arsenic and antimony, which needs to be given greater consideration. The analysis accounts both for the metals that are present and their expected lifetimes in the environment, and concludes that both CFLs and LEDs should be classified as hazardous waste, in particular because of their lead content, which can be leached at 132 and 44 mg/l, respectively, and well above the accepted threshold of 5mg/l.. The amount of copper is also at issue, being 111,000 and 31,600 mg/kg respectively, in comparison with the accepted limit of 2500 mg/kg.

In their favour, both devices last far longer and consume considerably less power than do incandescent bulbs; nonetheless, the presence of heavy metals is concluded to impart some 3 -- 26 times the environmental burden for CFLs, while LEDs are deemed to be worse overall by a factor of 2 -- 3 than their more established counterpart. It is concluded that not only must energy consumption be taken into account, but that a reduction in the levels of toxic materials incurred in the manufacture of such "green" technology should be factored in to the design.

These results represent an alternative reality, in terms of our use of materials, since they tacitly illustrate the point that the final disposal/reuse of materials used in the manufacture of all appliances and devices must be designed-in to the processes through which they are created. The supply of various elements is at issue, and efficient means for recycling them is the only way to avoid running out of, e.g. indium, helium, and many other vital materials within only a decade or so The notion of the circular economy is the overarching example of this line of thinking, which follows the patterns of Nature, in which there is no such thing as "waste". Everything in the natural world is recycled, e.g. though such agencies as the soil food web, where energy and materials are exchanged among an holistically interacting community of organisms, which may number in their billions, in a single teaspoonful of soil

In principle, we can reuse materials to fabricate new and replacement technology, so long as we have sufficient available energy to do this. It is the loss of cheap energy, particularly in the form of liquid fuels refined from petroleum, that will set an ultimate limit to the extent by which human civilization is underpinned by technology. When this begins to fail, we may nonetheless draw from the design models of nature, in adopting lower energy, intermediate technology paradigms, such as are found in the principles of permaculture Hence the environmental problems accorded from low energy light bulbs, and carbon emissions, will no longer be a feature for us, once we have become reconnected with the natural world.


Karen Blakeman said...

Recycling of CFL/LEDs is a major issue here. The local council do not offer local collection points so many of its residents are expected to drive out of town to their recycling centre to dispose of the bulbs. Hardly environmentally friendly.

The alternative for us is four bus rides(expensive) or a 3 hour round trip on foot along roads with heavy traffic belching out god knows what.

The council dodges the issue by giving links on its web site to Recolight/CoBRA ( The site helps you find one of their local collection points. The nearest for us is a DIY store about a mile away but when I asked in store where to hand in my CFLs they knew nothing about it!

I asked my neighbours what they did with theirs. "Put them in the rubbish bins" was the answer.

It's a disaster in the making and about time there was some joined up thinking (hate the phrase but sums it up) about dealing with the disposal of CFL/LED bulbs

Professor Chris Rhodes said...

The entire strategy seems to be mostly about a knee-jerk reaction and paying lip-service to "appearing green". It is ironic that even when there is somewhere to dispose of your light bulbs etc., and for recycling in general, often this is at some out-of-town depot, that you necessarily incur carbon emissions in getting to.

The quality of the light is another issue and so many people just buy a more intense bulb, above and beyond the power output that it is supposed to be "equivalent to". Of course the wavelengths are different between an incandescent filament and an electronic device.

As I note, the whole paradigm of manufacture and reuse of materials and components needs to be integrated in the original design,rather than ending up with "waste" that needs costly disposal. Underpinning all of these things, naturally, is how much energy we have available to maintain our technology.

Meanwhile, your local council ought to make some provision for collecting low energy bulbs, computers, and many other things that cause pollution (and resource wastage) in this country, or get shipped off to the far East, where they end up shortening the lives of those who earn very little for getting out the gold etc., using very primitive and unsafe means.

Humanity needs to find better, and regenerative designs, rather then the "once-though" approach that is exhausting our precious resources and engineering the environment in perilous ways.