The Second Version

07/12/06

The Scale Issue

Another concept that does not easily sink in is scale. I already treated related arguments, but this subject deserves more exposition.

Things can be big or small, but often this makes sense only in relation to some other things. For example, take a rock that fits in your hand. It is smallish on a human scale, but it would be a whole world for bacteria living on it. Compared to an entire mountain, that rock is insignificantly tiny, tho.

In absolute terms, we can only state dimensions and weight of the rock. But even units of length and weight are pretty arbitrary (this does not mean they are useless, anyway).

The scale problem is of paramount importance in the energy field. There's a lot of nifty processes and devices out there to produce energy from renewable sources, and they do work; they're not scams. But they are suitable only on a small scale: 1 kW here, 5 kW there. This can be good for developing countries - rural China and Africa - where some energy would be better than nothing at all. With 1 kW you can run a fridge and some lights, or an electric cooker.

But in the developed world, where electrical consumption is measured in terawatts (TW, 1*1012 W) , those methods are insignificant.

Related case, a story reported by Tigerhawk: a Norwegian company plans to make biodiesel from liposuction waste fat. All well and good: it is definitely feasible from a technical standpoint, and saturated animal fats would probably make a better fuel than unsaturated vegetable oils, which can undergo unwanted polymerization and oxidation reactions.

But this company plans to produce 10 000 liters/week of biodiesel from the waste of one hospital in Florida. According to this reputable source, around 4 000 000 gallons of fuel oil were sold daily in the USA. This means 105 980 000 liters of fuel oil per week; 10 000 liters are barely 0.01% of the total. That is, insignificant.

Even if the scheme were extended to all liposuction centers in the USA and produced 100 times the biodiesel, it still would make up 1% of the total - without taking into consideration the energy costs of collecting waste fat, processing it and distributing the biodiesel.

Such a scheme would work better in the (unlikely) scenario of a smallish village built around an isolated liposuction center. Processing waste fat in situ, without need for transportation, would then satisfy a good part of the fuel needs of the village.

It's all about scale.

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