Myth: We put a man on the moon, didn't we? We ought to be able to grow papayas in the Himalayas.

Not all policy-makers and not all citizens appreciate the limits imposed by the laws of thermodynamics. Some folks show blissful optimism. 

"What's wrong with an electric car?" they ask. 

Start with a particular number of gallons of crude. Pump it out of the ground and ship it to the refinery. Crack it down to heating oil. Transport it again, this time to the electric power plant. The parcel of crude we started with has already shrunk quite a lot in the refinery, and some was used up, indirectly, to supply the energy for its own processing and transportation. 

Next, burn up the refined oil to get heat to boil water to make steam to spin a turbine to drive a generator to produce electric power. There are heavy losses in all these steps, especially those resulting from the thermodynamic inefficiencies of that turbine. 

Now, put the electric power through a transformer to produce high voltage. More losses. Distribute it along wires. More losses. Transform it down to household level. More losses still. 

Finally, rectify the current and charge the bank of batteries in your little electric car of the future. There are losses to account for here, too. 

In the morning, unplug the thing and drive off quietly to work. You have enough electric charge to get you there and back again at moderate speed. 

Consider for a moment what the outcome would be if you refined the same amount of crude into gasoline and drove a conventional compact car to work with it. You would have enough fuel to get there and back again at moderate speed. The same distance, it turns out. 

"Yes, but," policy-makers and citizens ask, "can't the electric car be powered by nuclear-generated electricity?" 

Yes, but...

What we call progress is often marked by rediscovery. Thus, the renewed interest in the lighter-than-air craft, the bicycle, and the rediscovery of the versatility of coal as an energy resource. 

Coal was the first of the fossil fuels to become important. It is the world's most abundant fossil resource. There may be as much as a 600 year supply on reserve. But coal is unsuitable as a direct replacement for petroleum, particularly for internal combustion engines. 

Long ago, it was learned that clean fuels of many types can be made from coal. "Coal oil" is still the common name used in the rural U.S. for kerosene. It was produced from coal in the mid-19th century. "Town gas" or "water gas" has been produced from coal for use in urban lighting and cooking for a period of time extending well into the 20th century. 

During WWII, Germany demonstrated the technical feasibility of a large-scale coal conversion technology. Under price controls, cheap oil and gas returned to the marketplace after WWII, which led again to a general decline in the importance of "King Coal." 

Awareness that the petroleum age is coming to an end provides new impetus to develop a technology for producing low cost gases and liquid fuels from coal. Here we find that public expectations may be somewhat unrealistic. 

Synthetic fuel from coal is unfortunately distinguished from other rediscoveries. The technology is not economically superior to its predecessor, petroleum. Based on intrinsic costs, synthetic fuels are 50 times more expensive than crude oil. 

The requisite capital investment in technology development, plant, and equipment for coal processing is measured in billions of dollars. The only basis for revenue parity, though, is predatory pricing by a cartel. With the mere stroke of a pen, OPEC has been known to reduce prices, unthinkable as that once was. How then will the massive investments ever be repaid'? 

Would you like to sell your bike to buy some stock?

In the post-petroleum age, we'll have to find a way to run vehicles on water. Here's how. 

Coal is almost entirely carbon. Synthetic fuels must be hydrocarbons, molecules made of hydrogen and carbon. The basic requirement, therefore, is to add hydrogen to the carbon atoms in coal. 

In addition, heat must be supplied to the process. This heat subtracts from the total energy released by the synthetic fuels. In general, the reliance on coal-based "syn-fuels" will lower the efficiency with which we use our primary resources by a factor of three. Keep that in mind. 

Hydrogen is usually provided by reacting coal with steam. Water vapor. The most serious problem faced by synthetic fuels plants is their need for water. Not only is water one of the raw materials, but it is also needed for cooling. It takes two tons of water for each ton of coal processed, about twice the needs of an electric power plant of the same energy output. 

By the way, only open-pit coal is economical enough for synthetic fuels processing. In the U.S. the most promising plant sites are either in the arid Southwest, in the Four Comers area, or in the equally arid North Central region of the Dakotas, Montana, and Wyoming, where agriculture and industry compete for water. 

Bicyclists need water, too. Not very much, though.

Just before noon one day in late 1973, a certain bicyclist walked uninvited into the office of a distinguished econometrician and sat down. 

"What do you think of yellowcake?" asked the bicyclist. 

"It is nearly time for a luncheon appointment," replied the man of numbers. "You are not invited. Happy birthday, just the same." 

"Yellowcake has nothing to do with birthdays." 

"Of course not," the economist-turned-statistician said. He tapped his pipe into an ash tray on the desk beside his computer terminal. "Yellowcake is uranium ore, am I correct?" 

The bicyclist nodded. "When was the last time you analyzed what is happening with yellowcake?" 

The gifted econometrician took off his reading glasses and shrugged. He ran his fingers through his graying forelocks and smiled patiently at the bicyclist. "When was the last time you drove a car?" 

"But you do know about uranium pricing." 

"You'll have to excuse me, but I do have to get a move on or I'll be late. Maybe we can talk about the price of yellowcake later." 

"The price has been going up sharply the past few months," declared the bicyclist. 

"The prices of many things have gone up lately," said the man who had been deservedly acclaimed for predicting as much. 

"It's because of the energy crisis," said the bicyclist. 

"Good work, oh man of the wheel," said the econometrician, always generous with his praise. "And do you remember the rest of what you've been taught about supply and demand?" 

"This may be a little different." 

"Different?" The expert's analytic eyes sparkled with conviction. "With petroleum shortages worldwide, one might expect the price of uranium ore to go up. It is an alternative energy source, is it not?" The econometrician stood up and strode confidently to his private coat closet, one of the perquisites of his station. 

"What's different," said the bicyclist, "is that the costs for enrichment vary inversely with the quality of the ore mined, not just with increased demand. The quality of uranium ore has been steadily getting worse and the processing costs have gone from something like $5.00 per pound to nearly $7.00 per pound. 

The econometrician returned from the closet with his arm in one sleeve of his overcoat. The bicyclist stood respectfully and assisted him with the other sleeve. "Thank you," said the older, more knowledgeable man. "The unit price of petroleum has gone up by those kinds of percentages, and uranium enrichment is a petroleum-intensive process. Again, what differentiates the cost increases for yellowcake from... any other 'cake'?" 

"Along with the unit price increases, there are also more units of petroleum being consumed in the refining process due to the lower quality of yellowcake now being mined." 

"Look, I don't really have time to give you a long lesson today. Suffice it to say, when the yellowcake gets to some level, $10.00 per pound, say, the cost of nuclear-generated electric power will reach an uneconomic level, and the unseen economic hand will cause a shift away from nuclear power until the operating costs of fossil-fueled generating plants catch up. Given the conditions in the Middle East, that won't be long either." 

"You're undoubtedly right, but there's just this one other thing." 

"Better make it fast.” 

"Ok," said the bicyclist. "When you consider the energy content of the enriched uranium, not just the dollars -- " 

"Energy content?" asked the econometrician. 

"Yes, for grades of yellowcake requiring as much as $12.00 per pound of processing costs, the energy consumed to do the enrichment exceeds the energy eventually obtainable from the uranium!" 

The older man looked at his watch and grimaced. "I must leave at once. You go ahead and think about these problems. I have no doubt that you'll figure out how the law of supply and demand will prevail and bring the world's mix of energy sources into equilibrium. Life is full of economic trade-offs." And, with a wave of his hand, the econometrician dashed off down the corridor, calling back over his shoulder. "Goodbye for now!"
 
 

That same afternoon, the bicyclist was surprised to look up from his own desk and to see the venerable econometrician bounding through the doorway in shirtsleeves, eyes animated by some intense challenge to his powerful mind. 

"There is something different going on here," he exclaimed. 

"With the yellowcake?" asked the bicyclist. 

"Yes. of course. This business about energy content has me stumped. It is energy yield we have to be concerned about from here on. But that's physics, not economics." 

"As you suggested” said the bicyclist, "I have been thinking. In physics, even a small difference in degree can produce a difference in kind." 

"Can you be more concrete?" asked the econometrician. 

The bicyclist cleared his throat and groped for the precise words. 

"A body," he said, "with a specific gravity of 0.99 differs in density from a body with a specific gravity of 1.01 by a very small amount." 

"By only two percent," said the econometrician. "So?" 

"One of them floats."

The worst menace to our cities has to be the LMFBR, an unconventional nuclear power plant with an awkward name, Liquid Metal Fast Breeder Reactor. 

Uranium comes in two forms, isotopes. One is useful, the other is unuseful but abundant. Actually, just less scarce. Even the useful uranium must be enriched before it can be used as fuel inside a nuclear reactor. There, through fission, uranium makes heat, then through a turbine-driven generator, electricity. 

The useful uranium, of course, gets used up. Yet, nuclear fission should not be confused with burning, although the machine that uses up the uranium is often called a burner reactor, probably to distinguish it from the breeder reactor. 

You've doubtless heard some good things about the breeder reactor. "It will produce more fuel than it uses," enthusiasts proclaim. Seems almost like a miracle, a free thermodynamic lunch. Bicyclists and others have learned to be skeptical of such Utopian rhapsodies. 

The breeder reactor does use useful uranium for fuel just as the burner reactor does, except that the breeder also takes some of the unuseful uranium and breeds it into a useful fuel. Plutonium. 

You've doubtless heard some bad things about plutonium. "It's so radioactive, only a few pounds could kill every living thing on earth," detractors proclaim. "Plutonium doesn't decay for hundreds of thousands of years," they cry. "And you can make atomic bombs out of the stuff, too!" 

Nevertheless, the breeder reactor is regarded by many policy-makers as a promising energy alternative precisely because it does produce plutonium. Later on, some of the plutonium gets used up in the same reactor to make heat, then electricity. 

It takes quite a long time, decades, in fact, for a breeder reactor to breed enough plutonium for its own use. Even a fast breeder. All the while, the breeder acts like a conventional burner, using up useful uranium. Since there's about ninety times as much unuseful uranium in nature as there is useful uranium, the wait seems worthwhile. But, if we ever intend to use breeders, we'd better hurry. 

We don't want to burn up all the useful uranium as nuclear kindling before we can light up the plutonium "fires" in breeders. 

Enthusiasts are being somewhat generous, therefore, in representing the breeder reactor as actually producing more fuel than it uses. It merely salvages some of the unuseful uranium tailings. 

You're probably wondering about the LMFBR. Dystopia! The thing must eventually be abandoned. But not just because of plutonium or some worrisome nuclear incident. There is also an old-fashioned chemical problem in the LMFBR. 

Circulating deep within all nuclear reactors is a fluid called a coolant. Don't be misled by the term. It's anything but cool in there. And, unless you've been living in a cave, you already know what might happen if a nuclear reactor loses its coolant. 

A burner reactor like Three Mile Island uses water as a coolant.  A fast breeder reactor uses a liquid metal, the LM in LMFBR. In particular, sodium. 

It's hard to find a more chemically reactive element than sodium. A speck of it, dropped in a beaker of water, causes a minor explosion. Except in a chemical lab or a fire-works factory, you've probably never even seen pure sodium. Yet, for technical reasons, liquid sodium is the coolant of choice in the LMFBR. Moreover, unlike water, the stuff freezes at high temperatures, clogging pipes and hopelessly jamming pumps. 

Perhaps you can imagine how perilous future LMFBR projects will be for our cities.
 
 

In the post-petroleum age, some people expect fusion reactors to produce gigantic amounts of "safe" heat. 

It'll probably be safe enough. The problem seems to be getting the things going, not shutting them off. Fusion reactors should have no propensity for "melt-down," and they'll produce no radioactive wastes. 

The high temperatures in a fusion reactor, tens of millions of degrees, make possible the most thermodynamically efficient heat engines ever built. 

And talk about recycling! Using the waste heat from a fusion reactor, you can reduce any kind of trash to a plasma of pure chemical elements. 

Fusion reactors are like pieces of the sun installed on the surface of the earth. Accordingly, some experts say they'll raise the temperature of the biosphere. The main concern isn't that, however. It's fuel. 

The sun uses plain hydrogen for fuel. That won't work on earth for technical reasons having to do with our low gravity field. Fusion reactors here must use both heavy isotopes of hydrogen, deuterium and tritium. 

Deuterium is abundant in nature. One water molecule out of 5,000 has a deuterium atom in it. Enough in the oceans for countless millenia, except that for each deuterium atom, the fusion reactor must have one tritium atom. Tritium is radioactive, with a half-life of about twelve years, and thus is all but absent in nature. 

Tritium is best produced by breeding a particular metallic isotope; lithium six. The next question is, how much lithium six is there? 

Some estimates put it this way: If all the known lithium six were bred into tritium and consumed in fusion reactors, the amount of energy produced would correspond to that of our total worldwide petroleum reserves. 

The "fusion age," then, might last about as long as the petroleum age. Not indefinitely. The bicycle age wouldn't begin for another century or so. 

But first a fusion reactor has to be made to work.

Fusion might be the ultimate energy technology. Certainly the mightiest. Conceptually, fusion has many advantages over fission. Just what we'll need in the post-petroleum age. 

Fusion happens when atomic nuclei are held together with sufficient force to cause them to, well, fuse. It produces unimaginable amounts of energy. 

Thus shines the sun from ninety-three million miles away. Here on earth... the hydrogen bomb. 

To harness this ferocious energy source for peaceful uses, technologists must find a way to sustain controlled thermo-nuclear reactions. High operating temperatures make containment a seemingly intractable problem. At 50 million degrees, all known materials vaporize. Out of what do you build a reaction chamber? 

One of the leading ideas is called a "magnetic bottle." Another concept uses giant lasers. Both present horrendous technical difficulties. 

Despite hundreds of millions spent on research worldwide, even the initial goal of achieving a positive-yield fusion reaction continues to slip further into the future, often by as much as a decade per year. At that rate, by the end of this century, success will be projected beyond the end of the next. 

Not much for wishful thinkers to hang their hopes on.