Direct Use of Solar Energy

by Bill Duesing

First broadcast on WSHU/WSUF-FM, May 14, 1999

We can't live without energy. We need it to do the work of pumping our blood, growing our food, and building our shelters. For most of the hundred thousand or so years we've been on this planet, humans have used the sun's energy to do the work that needed to be done. The stored solar energy in the plants and animals eaten by our ancestors provided the energy to gather or grow that food, as well as to keep their communities functioning. Stored solar energy from plants and animals is still an absolute necessity for us to live.

Because the sun was the energy source they knew, people figured out ingenious ways to tap into its energy flow. They captured the sun-driven wind with sails on boats and on grist mills. They used the power of gravity's pull on solar-evaporated water to saw lumber and to irrigate fields. Stored energy in wood provided warmth and fuel for cooking food. Centuries ago, the natives of the Southwest created elegant cities heated by the sun in winter and cool in the summer by intelligent design.

Using just the sun's energy, the Egyptians built the Pyramids, the Chinese erected the Great Wall, the Greeks created Athens and the Native Americans built the great cities on the plains.

Only in the last several hundred years has anything other than current solar energy been used. The discovery of fossil fuels: coal, oil and natural gas, changed everything. With the possible exception of some natural gas remaining from the Earth's creation, fossil fuels contain ancient sunlight, captured by plants eons ago.

The solar energy in fossil fuels is very concentrated. The Earth's mineral reserves contain hundreds of millions of years worth of captured sunlight. We're on schedule to use up most of that in just a few hundred years. Once the extraction of these fuels began, our energy use increased dramatically. Since 1950, although the world's population has just about doubled, it uses six times as much energy. Several studies indicate that within a decade, we will have extracted about half the fossil oil that humans will ever use, that new oil will take more energy to produce than it contains, and that much of the remaining oil will be in the politically volitile Middle East.

Americans expect energy to be plentiful and inexpensive. They frequently complain about its expense even though we pay some of the lowest prices in the world.

How about some perspective, here. Let's see how much energy it takes to run a human being for 24 hours. The 2,000 to 3,000 calories each of us needs every day are equivalent to the energy in about one cup of gasoline. Our bodies use as much energy as a 150 watt light bulb uses running all the time - about three and a half kilowatt hours per day. That means that the energy to run an average person costs roughly 15 cents if we could get it from gasoline or 35 cents if we used our region's supposedly expensive electricity. (There's a lot of energy wasted in making electricity from fossil or nuclear fuels, so it's more expensive.)

Of course, the price we pay for energy doesn't even begin to cover its true costs. We pay more with our taxes to defend the Persian Gulf than the energy companies pay to buy oil there. Our excessive energy use causes expensive environmental problems: air, water and soil pollution, urban sprawl and acid rain to name just a few. The costs of recovery from global climate change-related floods, storms, and droughts are rising quickly.

And, we still haven't figured what it will cost to safely run the four, now-closed nuclear plants in Connecticut, much less the exorbitant expense of dealing with their very-long-lived poisonous wastes.

But, because individuals and businesses don't pay for these costs when they buy energy, kilowatts and gallons are so cheap that they've become the major ingredient in almost everything we touch, use, eat or drink. It could take most of a day to tally all the many ways energy is embodied in the teenagers driving the new cars out of the fast food joints with meals to go. Their bodies run on the energy in corn, wheat and potatoes, but this fast food meal and its delivery system consumes enormous quantities of fossil and nuclear energy.

It's time to go on a very serious energy diet and relearn how to sustain ourselves using solar energy. There are just too many warning signs of the hidden costs and the dangers of our increasing dependence on limited supplies of polluting fuels to continue down the high-energy-use road.

This is Bill Duesing, Living on the Earth


This page and its contents are copyright © 1999 by WSHU-FM, Fairfield, CT, and by Bill Duesing.