In a 1951 report for the Atomic Energy Commission, Palmer C. Putnam, inventor of the one of the world’s largest wind turbines and the DUKW amphibious transport vehicle, made some seemingly reasonable predictions about the the world energy system.

He noted the world’s “illiterate subsistence-farming populations” were “in demographic transition” to urbanized, higher-energy lifestyles. Meanwhile, “everything we know suggests that world population will double and may treble,” he wrote. (Perhaps you’ve heard similar sentiment now about a certain country in the Far East?)

More people with more more money meant that humanity would be using more energy, he reasoned. A lot more energy. The outcome of his thinking was the series of curves at the top of the post. Using different population estimates and energy demand growth rates, he came up with what he called the maximum plausible energy usage for from 1950 to 2000. The growth rates for energy demand he used don’t sound big — 3 to 5 percent per year — but what comes out of these accelerating scenarios is just astonishing.

Palmer Putnam predicted that in the year 2000, the maximum plausible energy usage for the world was 45,000 exajoules (or 43 x 10¹⁸ BTU). The curve predicting the lowest energy usage in 2000 showed that people would be using 32,000 exajoules (or 30 x 10¹⁸ BTU) of energy per year.

In reality, human energy consumption in the year 2000 totaled a mere 500 exajoules.

That is to say, to meet Putnam’s estimates, we’d have to rebuild every bit of our energy system 60 times over to meet his “minimum maximum.” Not only that, he underpredicted world population substantially, so his per capita energy demand was incredibly overblown.

What’s fascinating about energy demand scenarios like Putnam’s is that they seemed quite reasonable and buttoned up even. They seemed downright hard-headedly realistic. Except that they were totally crazy.

No fossil or renewable sources of energy could ever meet such a demand. Even taking the sunniest estimates, Putnam’s imaginary world energy system would burn through America’s coal reserves every few months! To make any kind of sense, Putnam needed not only massive amounts of nuclear power plants, but breeder reactors or fusion plants, which wouldn’t need limited uranium stocks. Never mind that finding enough metal and other materials to build such a fleet of plants would probably be impossible. Even assuming all materials could be found, the sheer scale of energy deployment required by Putnam’s energy estimates is astonishing.

“Perhaps it would be less costly, for example, to modify the pattern of the energy system so that nuclear fuels might bear half to three-fourths of the load,” he wrote. “Blanket electrification would be one way. Could we electrify most of the railroads and much of industry? Could we run overhead power lines along main toll roads and redsign trucks, buses, and cars for electric operation, relying on batteries for off-highway travel?”

Luckily, what Putnam saw coming never came to pass, but it’s important to remember that he and his estimates helped created the context in which energy planners and engineers worked. If this is where they thought the world was going, they would naturally favor huge power sources, not efficiency and renewable energy.

Steve Cohn has called this tendency the “technological aesthetics of mega-builders.” And Putnam was one of the great artists, his curves a masterpiece of the form.