Friday, August 25, 2006

Microprocessors - a Fragile Commodity - post "Peak Oil".

In July, I posted two articles about solar energy, and I estimated the amount of silicon that would be required to implement this technology on a scale to significantly supplant other (e.g. fossil fuel fired and nuclear) forms of electricity generation. If solar cells of ca 300 microns thickness were to be used, this amounts to 54 million tonnes of pure silicon, which may be compared with the 30,000 tonnes currently manufactured annually. Hence, a scale-up to around 100 times the present production capacity would be required to meet that demand over a 20 year period! Neither does the market auger well, since the existing and relatively minor increase in demand for silicon for photovoltaic technology has caused a bottleneck in supply, with the result that there is now a hike in the price of silicon. Placed in context, there is likely to be a rise in silicon contracts of around 50% to £31,000 per tonne this year over last. Spot prices are far greater, which some analysts put at around £130,000 per tonne. Ouch!!
I did note, however, that the quantity of silicon needed for significant production of electricity worldwide using photovoltaics could be dramatically reduced using "thin-film" silicon cells, otherwise I don't foresee its use on the wide scale, though it will remain important for niche applications. There is, however, pressure on other elements such as indium, in terms of the likely demand which could well exceed the available world resource of some of them.
Of course, a major use of ultra high purity silicon is in the fabrication of microprocessors "silicon chips" in computers. Where would the modern world be without them? I wouldn't be typing this here, and would need some other publication medium instead. A thin slice "a wafer" in accord with its extreme thinness, is first cut from a silicon crystal. The crystal does indeed consist of "silicon", since all traces of other materials are as far as possible removed, leaving silicon of 99.9999999% purity. A single atom of impurity in the wrong place can cause the silicon-based devices to "leak", and hence they are made under ultra-clean conditions, using ultra-high purity liquids and gases. The normal world of our experience, our bodies, water and air are too dirty to be admitted to any process involving chip manufacture. Mechanical dislocations on a minute scale are also enough to cause a chip to fail, hence they must also be engineered with inordinate precision.
John Hamaker wrote a book called "The Survival of Civilization" in the early 1980's in which he focussed principally on what factors might cause civilization to collapse. Hamaker was concerned particularly with the quality of soil, believing that it had become demineralized, but that if "rock dust" were deliberately ploughed into it, soil became far more fertile, and greater crop yields were obtained from it, of plants that were "healthier" since they too imparted minerals, into human and animal diets. He thought too, that "Remineralizing the Earth" (there is a group and web-site with that name) hold-back rising CO2 levels and allay global warming through helping the soil microbiota (bacterial and fungi etc.) to "fix" (absorb) CO2 from the atmosphere. Failure to do this, in his opinion, meant the collapse of civilization.
Surely civilization will collapse in the tailing availability of post-"Peak Oil", as it has become almost entirely reliant on cheap energy - much of that supplied in the form of oil, gas and coal, and from nuclear power, which requires the former primary fuels to extract its own uranium fuel. A strong case, as I have perhaps laboured in these articles to manoeuvre to a more localised social system, based around small largely self-sustaining communities.
A further factor is the matter of adaptation and knowledge. It is difficult for a complex society to adapt to such changes as I have just mentioned. Computers are by now absolutely central to the "global" economy upon which the modern world is based, for communication, and increasingly paper gives-way to electronic forms of data manipulation and storage. Most advanced machines, providing life-support in hospitals for example, require computers. How will we function if it is no longer possible to extract silicon and all the other raw materials, in order to fabricate computers, and luxuriate sufficient electricity to run them? How will we get hold of the "older" knowledge desperately needed by communities in the crisis that will inevitably follow Peak Oil?
We must begin to inaugurate a new infrastructure to cope in the "new world order" of things, which most likely will not involve computers. Sitting here typing this, such a world seems unthinkable, but we must think of it, and plan for sustainable existence within its scope.

No comments: