Most people will admit that from time to time they'd like to have a slave or two around the house to help with the business of living. Running a busy life takes a lot of personal energy, and an extra pair of legs can really take a load off! Are you aware that as a 21st century American you already have quite a few "energy slaves" to do your bidding?

That's right, "energy slaves." Let's compute how many of these you have working for you, unseen and maybe even unappreciated. The average sustained power output of a human being is about one-tenth to one-twentieth of a horsepower (depending on how fit and well-fed you are). Let's say you're pretty strong, and you can sustain an output of one-tenth of a horsepower.

Last year, the 296 million people in the USA used 97 quadrillion BTUs of energy (the BTU, or British Thermal Unit, is a measure of energy equivalent to a kitchen match which allows us to compare different energy sources). To put that huge number into perspective, each of us used about 328 million BTUs during the year, the equivalent of 96,000 Kilowatt hours of electricity. A Kilowatt-hour is about 1/3 more work than a horsepower-hour, so we used about 128,640 horsepower-hours, or the equivalent of 147 energy slaves working for each of us 24/7, all year long.

Now think about your energy slaves as you go about your day. Every time you leave a 75 Watt light bulb burning, one of these very strong energy slaves is pedaling away as hard as he can to keep it going for you. If that 25 mpg car has a 100 horsepower motor, it's the equivalent of 1000 strong people. If you add up all the power we Americans use, on average, to light and heat our homes, transport us, etc. and convert it to the human energy equivalent, it's an unimaginable opulence by the standards of all the humans who came before us. It is as if our well-being were measured by the number of energy slaves we have learned to command.

What powers our energy slaves? Nuclear provides 8%. Hydro, the image of electricity in the northwest, provides only 3% of total US energy, and other renewables like solar, wind, wood waste and biomass only about 4% combined. By far the most comes from the fossil fuel trio of petroleum (39%), natural gas (23%) and coal (23%). Fossil fuels won't last forever. Oil, in particular, will be depleted within decades - i.e., within the lifetimes of our children - and will be subject to shortages much sooner than that. When fossil fuels are gone, they will be gone forever.

According to "Consuming Power: A Social History of American Energies" by David Nye, the United States has the highest per capita energy use in the world: 40% more than Germany, twice as much as Sweden, three times that of Italy or Japan. Although Americans represent only 5% of the world's population, we use over 25% of the world's oil. If you'd like to explore your options for producing renewable energy or using energy more efficiently, check out the US Department of Energy's Energy Efficiency and Renewable Energy website at www.eere.energy.gov/.

Jennifer Barker is the director of Eastern Oregon Renewable Energies Non-profit, the organization that sponsors SolWest Fair (www.solwest.org). She is a certified Energy Auditor.