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The Environment and microchips

October 5, 2004

A public radio commentary

Last night, as I put together a PC, I examined the computer's memory chip - in technical parlance a 32 MB DRAM chip.

It seems innocuous: It has no moving parts and yet, because its part of the electronic revolution, will change the world. So revolutionary is the chip, that we've listened to a decade of jabbering about the "new economy."

The implication is that the microchip leaves behind the industrial world of manufacturing - the days of grimy work putting together things like washing machines or cars. No doubt, the microchip is revolutionary, but make no mistake, it is very much part of the old industry, as much as the new - in fact by some measure even more so. Its just hidden from us.

A key measure of the environmental impact of manufacturing something is the weight of fossil fuel required to produce it, relative to the product's weight.

For example, in building a car you need steel, plastics, paint, and so on. So, if you add up all the fuel used to make these parts, and then add in the energy needed to make the car itself, you'll find that for every pound of car produced, it takes two pounds of fuel. Now, compare this to a microchip - in fact, that 32 MB memory chip I mentioned. This tiny, non-moving thing takes an astounding 630 times its own weight in fossil fuel to make. How could this be possible?

Purity is the answer.

A chip is made of silicon, the main ingredient of sand. To work its magic the silicon used must be extraordinarily pure. If you were to shrink to the size of an atom and wander through the silicon used to make this chip, you'd pass by a million silicon atoms before you'd find a single impurity. Any more than that and the chip wouldn't work. Now, to purify sand to that point takes a huge amount of energy - about a quarter of the total energy needed to produce the chip.

In addition, all this work must be done in a clean room. That is, a room which is many times tidier than a hospital operating room. The climate and ventilation of the room must be rigorously controlled. This takes about 50% of the energy used to make the chip.

So, the upshot is this: During its lifetime a microchip uses very little energy, but it takes a great deal to produce it.

For example, if you buy eight new computers over a period of ten years, the total energy used would equal that needed to produce a car.

So, this notion that the microchip makes for a brand new economy is only half right. It's very useful to keep our eye on that other half that is still the old, industrial manufacturing. It reminds us that there is no free lunch.

Copyright 2004 William S. Hammack Enterprises