Stare at Amory Lovins' domed forehead long enough and you get odd ideas: You could show movies on it, beat wet clothes against it, cover it with drywall. If his face were on Mount Rushmore, climbers would bivouac on an eyebrow for a week, despair of finding a route up the bulging expanse and humbly retreat down the nose.

This morning, the redoubtable brow is glowing in the Colorado mountain sun, as Lovins sips tea and looks out across the greenhouse that forms the center of his combined home and office. Nanuq, his bull terrier, is drinking out of the greenhouse's sunlit aquaculture tank, while five kinds of edible fish clump in fear on the opposite side. Overhead, a photovoltaic-powered fan spins lazily. It's a peaceful scene, but the subject at hand is the explosion of the Soviet reactor at Chernobyl, and the conclusions hatched by this formidable frontal lobe are worrisome:

"Until this happened, nobody thought a graphite reactor could blow up," Lovins says. "That one was not in the book. In fact, the consensus was that graphite reactors are inherently safer than American light water reactors, since we do know some ways light water reactors can blow up . . . "

"The American industry's assurances that Chernobyl had no containment were not true. It had a containment vessel about half as strong as our strongest and twice as strong as our weakest. The Soviets didn't call it a containment, they called it an airtight biological shield, but its function was that of a containment . . . "

"The deeper lessons are not technical, they are human. It is absolutely appropriate to draw comparisons between their system and ours, because what they had was a management failure, and we have them all over our system. The reason I call it an inevitability instead of an accident is that if you put megaton inventories of fallout inside bottles, sooner or later somebody will screw up enough to let it out."

The voice is calm, the speech precise, the thoughts vintage Lovins, a discourse on the limitations of nuclear power, without emotion. The man who over the past decade has established himself as the most persistent and scientifically literate burr under the nuclear industry's saddle may have the heart of an insurgent, but he has the mind of a scientist.

In Lovins' view, nuclear power is more a symptom than a disease -- the latest and most blatant example of America's skewed energy planning. He has spent the last 10 years urging Americans to understand that we are at a historic energy crossroads. We can continue down what he calls the "hard" energy path, which is based on huge, centralized energy plants that are unprofitable, wasteful, polluting, accident-prone and vulnerable to enemy attack; or we can veer onto the "soft" path of dispersed, cheap, efficient, safe, clean, and renewable technologies.

Specifically, Lovins has suggested we begin to step back with him and see the big picture: that we don't necessarily have to build giant power plants and strip and drain endless amounts of uranium and oil to keep society humming. The soft path he advocates is not a single prescription, but a careful matching of energy supplies to energy uses so that little is wasted, which saves money and -- almost incidentally -- the environment. This could mean wind power is right for Southern California, a small dam makes sense for rural Kentucky, utility-sponsored home-weatherization is the best choice for New York. As it turns out, says Lovins, this "end-use, least-cost" planning reveals that nuclear power doesn't make sense anywhere. It's not evil, it is impractical -- a far more damning flaw.

Although he says he was only trying to "save the utility executives from themselves" when he advanced his soft path concept in 1976, many power plant executives regarded him as anarchy incarnate, an activist and a rebel determined to undo a system of generating power they had spent decades building. These days, he finds it a "charming irony" that he and his wife Hunter have been invited into the board rooms of major utilities. There they quietly point out nuclear power's poor gigawatts-to-dollars ratio, and that practical, environmentally safe alternatives would lower costs and boost revenues. For this advice the Lovinses collect up to $5,000 a day. In recent years they have consulted with utilities in 13 states.

"I owe a lot to Amory," says Peter T. Johnson, administrator of the Pacific Northwest's Bonneville Power Administration. "I am a business person, and what he said to us made eminent sense . . . his insights have helped us to be vastly more healthy financially than we were three years ago."

"If Amory were just antinuclear, he would be one-eighth as effective," says Deborah Bleviss, director of energy and environmental studies for the Federation of American Scientists in Washington. "The weakness of the antinuclear movement has been its failure to point out alternatives."

As the sun arcs over the greenhouse and Lovins finishes his tea, the conversation drifts to dogs. Lovins scratches Nanuq's ears. He dotes on this dog. Soon he begins reciting technical specifications for bull terriers, including a bite that develops "2,700 psi pounds per square inch ." Lovins has what he calls a "loose-leaf mind," one that compulsively stores everything from statistics on Western European energy use to particulars of knee anatomy to facts about bull terriers. It is all important, he says, because "everything is related. The world isn't reductionist; it is a complex web of interconnections which go on working whether we perceive them or not."

This Lovinsism has a corollary that he often uses to describe nuclear power: "Problems are often caused by prior solutions."

S EVEN THOUSAND feet up, near the tiny town of Old Snowmass, Colo., Lovins' home grew straight out of his theories: The best way to ensure abundant supplies of energy is to use less in the first place.

A visitor's first obligation is a tour. From the greenhouse, which yields tomatoes, zucchini, yellow squash, oranges, lemons, chard, cucumbers, tangerines, bananas, grapes and papayas, the soft-tech wonders ripple out over the structure's 4,000 square feet: quadruple efficiency light fixtures, low-flow showers, toilets that flush with a scant gallon, a passive-solar water heater, even a superefficient photocopier. The walls are made of freon-filled polyurethane insulation sandwiched between two six-inch-thick courses of stone and mortar. The house is up near the tree line in the mountains, where last year the growing season outside was 28 days, yet inside there is no furnace: All heat comes from sunlight streaming through the windows -- two backup woodstoves have proved to be unnecessary, even when the temperature hit 47 below last winter. It is a pleasant, even luxurious, place, consistent with the Lovinses' belief that living lightly on the Earth need not involve sacrifices.

Lovins estimates the building uses 10 percent of the usual amount of electricity and half the normal amount of water. He says utility bills average $28 per month, two-thirds of that for office equipment. The house, completed in 1983, cost $500,000, financed through the Lovinses' savings, an intensified consulting schedule and several loans. Hunter Lovins says this expensive, spacious house was built to impress visiting corporate executives, but it could all work on a much more modest scale. Lovins estimates it could pay for itself in 40 years on energy savings alone.

Lovins's personal statistics are just as formidable: Harvard at 16, Oxford at 19, consulting experimental physicist and a visiting professor at five universities. He has briefed five heads of state, lectured on energy policy in 15 countries and was tagged by Newsweek as "one of the western world's most influential energy thinkers." He is 38.

He is self-effacing, often referring to himself as a "techno-twit." He looks the part -- black horn-rims, pocket stuffed with pens and slacks of an odd shade of blue that meets the nerd's fashion credo: a color not found in nature. Since moving west he has swapped his Wallabies for cowboy boots and he occasionally dons a ten-gallon hat, but he retains the pallor of a hard-core bookworm. "Your basic troglodyte," he says somewhat sheepishly.

Science was a natural obsession for the son of a scientific instrument-maker in Silver Spring. Born with a deficit of gamma globulin, he spend a pneumonia-wracked youth peering through "the largest optical microscope ever made" and playing the piano (he composed at age 7, but eventually abandoned a potential concert career as too narrow). As a high school student he eagerly embraced the sexiest technology of the early '60s, a shining wonder called nuclear power. At 16, he achieved the ultimate dream of the pocket-protector and slide-rule crowd: a national award for physics research presented by Glen Seaborg, Nobel Prize-winning codiscoverer of plutonium.

While a teen-ager, he was taking graduate courses in linguistics and applied mathematics at Harvard. At 21 he became the youngest Oxford don (a junior faculty position) in 400 years. Though Oxford had courted him by offering to let him "essentially do whatever I wanted for three years," his stated desire to study energy policy bothered the registrars. "This was two years before the oil embargo, so energy was not an academic subject yet -- they thought it was best left to the oil engineers. But I could see that it was a tangled mess that involved many disciplines, and no one was taking a broad view of it. It fascinated me."

Still, the brilliant scholar might have chosen a more respectable major and surrendered to the "seductive academic life" were it not for his first real-world environmental fight. To strengthen his congenitally weak knees, he had begun hiking in the hauntingly beautiful glades of Snowdonia National Park in northern Wales -- one of the last truly wild lands in Great Britain. When he discovered that a giant copper-mining company was pushing for mining rights in the center of it, he wrote a book for the environmental organization Friends of the Earth called Eryri, the Mountains of Longing. The imagery revealed a powerful love for nature beneath the mantle of the techno-twit:

. . . the light . . . pours molten across the ridge, level with the flowing sky, and it lives in each snowflake and frost-feather. It makes the ice smoke and the rocks rise up . . . I am here, drunk with light.

And when the mining company withdrew, he had learned something else: that the typewriter, wielded carefully, is mightier than the dredging shovel.

Along the way, his infatuation with nuclear power waned. "I started to realize how much they didn't know. I think I am one of a half-dozen people on Earth who have actually read all of the old records of the Atomic Energy Commission's hearings on emergency cooling systems. That experience really impressed me with how much they did not know about how safety systems would work. There were many assumptions with very little technical basis."

So, because Oxford was pushing him to specialize, and "I thought the world had enough specialists -- it needed people who could make connections that had not been made," he left Merton College with no degree (he has since been granted an MA by special resolution), a love for nature and a mind stuffed with physics, geology, biology, business and the myriad disciplines that meld in energy policy. He began a 10-year stint in England hammering out books and papers as energy specialist for Friends of the Earth. Each year he returned to the United States for at least three months.

By 1976, his analysis had ripened, and he wrote a seminal article in Foreign Affairs magazine called "Energy Strategy: The Road Not Taken?" A year later it appeared expanded in a book, Soft Energy Paths: Toward a Durable Peace.

He said American energy policy had been driven by one rule: make power, plenty of it. Through subsidies, government encouraged construction of huge plants in the belief that vast reserves of power were the lifeblood of modern civilization.

The result, he said, was an oversupply of electricity -- the most expensive form of energy -- and customers were encouraged to use it for tasks such as home heating, a wasteful mismatch he calls "cutting butter with a chain saw." Far better, he argued, to reserve electricity for those gadgets it runs best -- TV, computers and lights, for example -- and use natural gas, or better still, solar energy, to heat homes. Generally, he said energy supply should be tailored to fit energy needs -- planners should always ask "how much of what kind of energy will do each task in the cheapest way?"

Finally, he said the greatest untapped energy "resource" was efficiency. He likened American energy use to a leaky bathtub. "Since we can't keep the bathtub filled because hot water keeps running out," he wrote, "do we really . . . need a bigger water heater, or could we do better with a cheap, low-technology plug?"

In short, he said the goal should be the "least-cost mix of all ways to make and all ways to save energy." It was a powerful idea because it held promise for both the user and the supplier. Users could save by consuming less energy, while suppliers could save by not building new, expensive plants, or running existing, wasteful plants at a loss. "It's a win-win situation," says Lovins.

"I was dazzled by that article," says Raymond Watts, who in 1976 was general counsel to the Senate Select Committee on Small Business and set up a Senate hearing to pit Lovins against nuclear proponents.

*"Lovins won the debate absolutely hands down," says Watts. "I remember commenting to Senator Gaylord Nelson that he struck me as Galileo and Jefferson rolled into one."

From that December morning onward, Lovins has been in demand as a speaker, author and consultant, sometimes logging 150,000 air miles in a year. Colleagues say if he had a weakness, it was his tendency to use energy technospeak: Joules, load durational curves, even "enthalpic equivalents."

But this was resolved in 1979 by his marriage to Hunter, a California attorney and environmental activist who describes herself as a "rough-living, beer-drinking, country-music loving cowboy." She shares coauthor credit on the last five of Lovins' 12 books. Her mark is evident. His affection for reams of figures had make his earlier works heavy sledding, but the cowritten works are flowing and readable.

"Amory has a tendency to think that the technical arguments alone will persuade people," says Hunter, 36. "But I know that people also respond to style, to how something feels."

"It's a classic case of opposites attract," says Lovins. Hunter skins sheep, brands cattle, wrangles horses and spends Fridays swirling to cowboy swing music at the local bar. Lovins likes classical music and goes to bed early. Their differences are exemplified by their horses' names: Hunter's is nicknamed Demon, Lovins' is called Butterball.

Hunter is the executive director, and Lovins is director of research, of the Rocky Mountain Institute, a 19-person nonprofit think tank the Lovinses have assembled in this stone-and-glass edifice to apply their insights on energy policy to fields ranging from agriculture to water use to national security. The Lovinses don't seem to mind that their home is also a busy office, a demonstration facility (about 4,900 visitors have signed the guest book in three years) and a staff lunchroom where RMI's biologists, engineers and economists eat eggs from a solar-heated chicken coop and home-grown greenhouse vegetables.

At night, when only Amory and Hunter remain, a bright band of stars shines through the greenhouse glass overhead. Hunter is in the kitchen frying chops from a pig that she raised, killed and skinned. Nanuq is snoozing on a dining-room rug. Lovins plays the upright piano. Tonight, it is a rippling tune called "Waves," a light piece, like sun on the water, but unexpected minor chords provide weight and depth, giving it a complex, poignant undertow.

Lovins wrote it when he was 11.

Lovins is not given to gloating, but this is a sweet time for him. As he anticipated in the mid-'70s, nuclear power is in sharp decline, done in mostly by economic troubles.

On the positive side, the workability of his soft-path ideal has been demonstrated at utilities such as Southern California Edison, which uses more solar, wind, geothermal, and small hydro power than other utilities, and has an innovative conservation program that last year gave away 109,000 high-efficiency light bulbs to low-income customers. While other utilities flirt with bankruptcy, SCE's stock price has hit all-time highs for five consecutive years.

To a lesser extent, other utilities have followed suit. Utility loans to weatherize homes are now commonplace. Lovins says utilities have finally realized that "It is cheaper to save electricity than to make it -- even in existing plants."

Still, Lovins has no shortage of critics.

Perhaps the largest volume in RMI's vast library is what Hunter calls "the green paperweight." It is a two-volume, 2,000 page collection of Congressional hearing records and documents springing from Lovins' 1976 article. Lovins calls it "the Lovins Versus the World" debate. It has since been boiled to a 410-page popular book called The Energy Controversy: Soft Path Questions and Answers.

"I spent a year of my life responding to every challenge I came across," says Lovins, though in a rare display of pique he says he grew tired of making "tedious responses to fatuous critiques."

Some of the anti-Lovins statements, such as "the safety of reactors is unparalleled," have not aged well since 1977, but others persist. Frequently, he is accused of social engineering, using energy policy to create a Brave New World of decentralization and individual empowerment, and bending the truth to get there. Lovins responds that he "explicitly assumed no significant change in where we live, how we live or how we run our society," and that he "goes to a hell of a lot of trouble to make the phrasing accurate."

Bruce C. Netschert, an energy economist who testified against Lovins for several Wisconsin utilities, says Lovins is indiscriminate. "He is saying that each and every utility company should go the conservation route rather than looking at the possibility of increasing demand. He has a broad-brush approach."

"I have never said that," says Lovins. "I have said that a utility should try to increase demand only if that is the cheapest thing to do. I simply have not found a utility yet for which that is the cheapest thing to do."

Others claim he makes groundless assertions. Thomas Kuhn, executive vice president of Edison Electric Institute, a private utility association that has battled Lovins for a decade, says, "Amory's figures are often quite distorted. He is famous for making broad, sweeping statements that have not held up."

To a certain extent, his supporters agree that some of Lovins' contentions are difficult, or impossible, to back up to everyone's satisfaction. Dennis Hayes, former director of President Carter's Solar Energy Research Institute, says, "Amory has taken a huge body of information and has had to simplify it to make it fit -- it's a necessary and essential part of the process. He'll say, 'There are a million solar houses in America.' Well, you can pick that apart forever: Do large, south-facing windows make a solar house? Or is it based on some equation, degree days per square foot, or something like that?

L OVINS IS NOT GIVEN to gloating, but this is a sweet time for him. As he anticipated in the mid-'70s, nuclear power is in sharp decline, done in mostly by economic troubles.

On the positive side, the workability of his soft-path ideal has been demonstrated at utilities such as Southern California Edison, which uses more solar, wind, geothermal, and small hydropower than any other utility, and has an aggressive conservation program that last year gave away 109,000 high-efficiency light bulbs to low-income customers. While other utilities flirt with bankruptcy, SCE's stock price has hit all-time highs for five years.

To a lesser extent, other utilities have followed suit. Utility loans to weatherize homes are common. Lovins says utilities have finally realized that "It is cheaper to save electricity than to make it -- even in existing plants."

Still, Lovins has no shortage of critics.

The largest volume in RMI's vast library is a 2,000 page collection of Congressional hearing records and documents based on Lovins' 1976 article. Lovins calls it "the Lovins Versus the World" debate. "I spent a year of my life responding to every challenge I came across," says Lovins, though in a rare pique he says he grew tired of making "tedious responses to fatuous critiques."

Some of the anti-Lovins statements, such as "the safety of reactors is unparalleled," have not aged well since 1977, but others persist. Frequently, he is accused of social engineering, using energy policy to create an age of decentralization and individual power. Lovins responds he "explicitly assumed no significant change in where we live, how we live or how we run our society."

Bruce C. Netschert, an energy economist who has testified against Lovins, says Lovins is indiscriminate. "He is saying that each and every utility company should go the conservation route rather than looking at the possibility of increasing demand. He has a broad-brush approach."

"I have never said that," says Lovins. "I have said that a utility should try to increase demand only if that is the cheapest thing to do. I simply have not found a utility yet for which that is the cheapest thing to do."

Thomas Kuhn, executive vice president of Edison Electric Institute, a utility association that has battled Lovins for a decade, says, "Amory's figures are often quite distorted. He is famous for making broad, sweeping statements that have not held up."

To a certain extent, his supporters agree that some of Lovins' contentions are difficult to back up to everyone's satisfaction. Dennis Hayes, former director of President Carter's Solar Energy Research Institute, says, "Amory has taken a huge body of information and has had to simplify it to make it fit -- it's a necessary and essential part of the process. He'll say, 'There are a million solar houses in America.' Well, you can pick that apart forever: Do large, south-facing windows make a solar house? Or is it based on some equation, degree days per square foot, or something like that? But he is conveying a truth -- that we have seen a significant change in how America is building its buildings."

Some say the message has gotten through. Since 1973, total energy use per capita has declined. "I attribute a lot of what has happened in the way of leveling load growth to Amory Lovins," says Vic Reinemer, editor of Public Power magazine, who calls Lovins' supporting evidence "meticulous . . . He has opened the dialogue with literally hundreds of people."

"You must realize this," says Prof. Arthur Rosenfeld, program leader of the Department of Energy's building efficiency laboratory at the University of California at Berkeley. "In this country we spend $470 billion dollars on energy a year -- that's ahead of medicine at $400 billion, and ahead of the military at around $300. That's why what Amory is doing is so vital. He's an articulate, effective spokesman, and even if someone advances our understanding of the need for conservation only slightly, he is saving a vast amount of money."

Political pigeonholers have a tough time with the Lovinses. Praise has come from former members of the Joint Chiefs of Staff, the Daughters of the American Revolution and the editors of the Whole Earth Catalog.

"If anything, we're deeply conservative," says Amory, "although people who call themselves social liberals will like the outcomes." The spirit of Thomas Jefferson, of "governing best by governing least," is often invoked up here in the purple mountains. The premise is that the security of a nation lies not just in its weaponry, but in secure, resilient, economically viable communities.

That Jeffersonian ideal has found its newest expression in RMI's Economic Renewal Project. Run by Hunter and RMI's assistant director Michael Kinsley, the project takes as its model towns such as Osage, Iowa, population 3,800, where the municipal utility helped its customers use energy more efficiently. The Lovinses say this allowed the town to retire its debt, accumulate a $2 million surplus, and lower electricity prices by one-fourth.

Now, RMI is starting a program in nearby Carbondale, Colo. The idea is to develop a blueprint for renewal that can be used in thousands of economically depressed small towns. Hunter and Kinsley are encouraging local entrepreneurs to sell locally raised food, lend to local businesses and generally plug economic leaks. What they learn will go into a 600-page workbook, to be further refined at their next stop, three rural towns in North Carolina.

The photovoltaic fan spins, the pig in the pen outside snuffles, Nanuq sniffs through the greenhouse for her ball. The light, always changeable in these mountains, has gone soft and gray. One is struck by the Lovinses' mood: People in conflict with the status quo are generally insecure, angry or both, but they seem optimistic. "Our pat phrase," Lovins says, "is: We want to save the world and have fun." CAPTION: Picture 1, The self-styled "technotwit" with his wife hunter.; Picture 2, The Lovinses' $5000,000 home in Old Snowmass, Colo.; Picture 3, Hunter and Amory Lovins and their bull terrier Nanuq. The couple has collaborated on five books.