Addicted to cheap energy
Even three hundred years ago almost all of our motive energy came from our own muscles and from those of our draft animals. A significant proportion of a farm was required to produce food for the draft horses: perhaps a eighth of the farm (a single draft horse might need a hectare of land for its food). Farms were much smaller than at present and at least six horses fit for working were required at any one time; others were too young or too old to work. Our energy and the energy of our draft animals was valuable.
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Evolution of human energy useSo long as we could simply pump oil out of the ground, process it quickly and easily, and burn it for energy we had a plentiful supply that was much cheaper and more convenient than the energy of draft animals. We became addicted to it. A similar story could be told about the development of electric power. The main difference with this was that it was often (especially in Australia) generated by burning another fossil fuel: coal rather than oil. And the process fed off itself. Cheaper energy to power drilling rigs and mining machinery meant that we could drill new oil wells and mine coal more cheaply than ever before.
In the early twenty-first century we need to kick the cheap fossil fuel energy habit because climate change is going to destroy the world as we know it, but we can't.
The declining cost of energyAccording to Wikipedia a healthy, well fed, labourer can produce about 75W of power for 8 hours. The national minimum wage in Australia is $17.70 per hour; so $17.70 for 75 Watt-hours is a cost for human labour of (about) $0.24/Wh or $236/kWh or $236,000/MWh.The cost of the energy from draft animals would have been cheeper than the cost of human muscle energy, perhaps a tenth the cost, so say $20,000/MWh.
Relationship between cost and consumptionUnfortunately there is a quirk of human nature that encourages us to use wastefully anything that is cheap. So as energy became cheaper and cheaper we used more and more of it, leading to more and more emissions of greenhouse gasses and health-damaging smoke and smog. |
References and related pagesExternal sites...On this site...Australia's energy futureMilestones in the development of human society Offshore wind farms; especially relating to Australia South Australia's success in developing renewable energy Do we want cheap energy or do we want to protect the planet? |
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