Energy in
the U.S.
Per-capita use in 1800s |
In the mid-1800s, U.S. citizens
who had the money to travel did so by using trains, but most people simply
stayed home. Electricity was not available. Lighting was
by tallow candles or whale-oil lamps. Homes were heated by wood,
primarily.
Let us ignore the energy expended by horses, mules, and oxen, and ignore the wind energy that drove the ships at sea (often whaling vessels), and ignore the energy from farm windmills and small hydro-powered grist mills and factories. Then the annual per-capita energy used by U.S. citizens of the era amounted to 110 gigajoules. On a year-round average, this amounts to 3400 joules per second, or 3.4 kilowatts. [Note: the watt is a measure of power --- energy divided by time --- whether that power be electrical or not.] In the late 1990s, the picture is much different. We scurry around in automobiles, reheat our coffee in microwave ovens, live in centrally heated homes, and have air-conditioned homes, offices, and cars. We fly around the country in jet planes, sitting next to passengers using lap-top computers. We send merchandise all around the country in trucks. Our present per-capita consumption of energy is 360 gigajoules per year, amounting to an around-the-year average consumption of 11,400 joules per second, of 11.4 kilowatts. What's that? We only use 3.3 times as much energy per capita per year as our forbears of the 1800s? That is correct.
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