Originally published in Outside's September 1987 issue

If character can't be quantified, maybe evangelical passion can. Amory Lovins traveled more than 200,000 miles last year, spreading the gospel of energy efficiency. His Honda CRX gets 60 miles to the gallon in the mountain air of Colorado; it's white, which saves about one-fourth of the cooling load on the air-conditioner. His third-generation Hewlett-Packard 15 C calculator rides in his shirt pocket like a sidekick, always ready to discombobulate foes with a fusillade of brilliance. Even friends sometimes find the heavy technical flow (of watts and joules and units of primary energy consumed per dollar of GNP) a little overwhelming.

"Talking to Amory is like trying to drink water from a fire hose," says his wife, Hunter, who serves as executive director of the Rocky Mountain Institute, the nonprofit educational and research foundation they started in 1982; she's also a member of the Basalt Volunteer Fire Department and a veteran of the Colorado rodeo circuit, and on Tuesdays she moon­lights as a bouncer at a cowboy bar. The Lovinses' house in Snowmass, at 7,100 feet, also serves as RMI headquarters and as a showroom of energy-saving technologies. It is one of the most innovative and efficient lairs in America by a factor of—well, what could make the point better than the banana tree growing under the argon-filled R-5 Heat Mirror windows in the greenhouse? Lovins claims the world's altitude record for passive-solar bananas and a household electric bill of $5 a month. More than 30,000 people have stopped by to see the low-flow shower heads (which use 1.5 gallons per minute, compared with the usual four to seven), and the Swedish Ifö toilet (which flushes with three liters of water instead of 20). The two iguanas in the bougainvillea, Iggy and Juana, are no more energy efficient than standard pet-store models, but they make an arresting sight, linking the Triassic Period of the dinosaurs with the Soft Path future of superefficient toilets.

Even at 27 pages Lovins's resume doesn't tell the whole story. He composed his first piano music when he was seven, received a patent on nuclear magnetic resonance technology when he was 17, and did work reported in the Journal of Chemical Physics (his first publication) long before he could vote. He has clients and contacts and friends in more than 30 countries. He's met with eight heads of state. He never graduated from college but has six honorary degrees. He can get around in a dozen languages. He earns $7,500 per speech; if the cause is congenial, he'll lecture for expenses, mixing esoteric technical terms with vivid analogies: Aircraft carriers get 17 feet per gallon, and the rain in the eastern United States can be as acidic as tomato juice. He's universally credited with the line that heating your house with electricity is like cutting butter with a chainsaw, but he didn't say it first, and every time he runs into Doug Kelbaugh, a professor at the University of Washington, he apologizes. Lovins did make what may have been the sharpest op-ed point of the Gulf War, succinctly asking, "Are we putting our kids in 0.56-mile-per-­gallon tanks because we didn't put them in 32-mile-per-gallon cars?"

In 20 years of number-crunching Lovins admits to making only a handful of mistakes—three, actually. The worst was on the day he testified on behalf of some clients at a hearing in Ontario, when he was wrong by a factor of 8,766. He was embarrassed, quickly traced the genesis of the boo-boo, and waived his fee. His prescience, debating skills, powers of synthesis, vast network of contacts, catholic curiosity, and ability to slice across intellectual boundaries are unrivaled in the energy field. He is a walking Whole Earth Catalog of technical resources, but he eats meat, reveres market forces, and sometimes wonders if he's a Republican. "If you had to list the top ten energy experts in the world," says his friend and fellow energy analyst Charles Komanoff, "Amory would have the first five spots."

In many ways the energy debate in America can be divided into two periods: Before Lovins and After Lovins. The moment of demarcation came 15 years ago when, at the age of 29, Lovins published an article in Foreign Affairs that changed the world.