"In houses with a south aspect, the sun's rays penetrate into the porticoes in the winter, but in summer the path of the sun is right over head and above the roof, so there is shade. We should build the south side loftier to get the winter sun and the north side lower to keep out the cold winds."

This quote comes not from Bob Veela of This Old House, nor from some Carter administration Department of Energy hack.

The quote belongs to Socrates, who lived in a 5th century energy crisis. After cutting down their own forests for fuel, the ancient Greeks were forced to import shipfulls of timber from Thrace and Macedonia.

The Romans deforested much of Italy to fire their public baths, which consumed whole trunks at a time. They eventually built their homes to take full advantage of the sun's rays, and, being Romans, made laws to protect access to sunlight. Builders could not raise a structure that would cast shade on their neighbor without a special permit and a dispensation from the courts.

American colonists located farmsteads on south-facing slopes and planted windbreaks on the northern side of their homes. Residents of Cape Cod, contending with massive deforestation of their peninsula, built tidy homes with south facing windows and roofs that sloped to cast off the north wind.

True, this was common sense. But fashion has always been a more urgent mistress, especially when fashion comes cheap. The 19th century ushered in an era of cheap coal delivered by train. According to Orchard Professor of History in Landscape Development John Stilgoe, this inexpensive fuel and inventions such as tar paper, which could seal out the wind, led Americans away from energy-conserving design practices.

New houses faced the road, not south. Instead of turning a cold shoulder to winter winds, the north side had windows to admit light and a view. The 20th century brought cheap oil and labor-saving furnaces, and Americans neglected energy conservation until the 1973 oil embargo reawakened interest in some old fashioned ideas.

"We'll always be grid-connected," Aaron said. Joel, a carpenter from Somerville, disagreed. "We will be as long as we let the big corporations control us. But there is no reason, no reason whatsoever, that we can't be energy independent. The technology is out there, they are just keeping it from us."

Joel went on like this for a while. "The big corporations don't care about people, they don't give a damn, all they are interested in is money. Don't let anyone tell you different. It's all about profit."

Aaron was the realist in the car. Jenny, his friend, sat silent in the front seat and rolled her eyes as Joel presented one conspiracy theory after another. I took notes.

An architect who lives near Harvard Square, Aaron arranged this outing to visit three solar-heated homes in suburbs of Boston. A dozen others would join us at the first stop out in Lexington.

The solar movement attracts all types, but it attracts some types more than others. Supporters of Jerry Brown, for example. There must be some high school physics teachers and corporate executives wedded to the technology, but I haven't met any. Solar energy represents, for one thing, freedom from the grid. Solar heating? Good-bye ConGas. Solar car? Adios Texaco. Photovoltaics? Nice knowing you, Northeast Utilities.

That, anyway, is Joel's dream.

Utility companies don't seem to bother Aaron, but needless waste does. "Solar heating is just so obvious. We know how to build a home that consumes less energy, but it is so hard to change the system. You are fighting against this big inertia of contractors who keep on building houses they way they have been building them since World War II."

Some MIT professors in the 1950s started studying energy efficient home designs, sharing their research with anyone who would listen. The federal government didn't do much listening until the oil crisis in the 70s, and then started listening very carefully. The Carter Administration offered now-notorious tax breaks for new homes fitted with solar devices.

"There wasn't much knowledge out there and a lot of people rushed in and called themselves solar experts," Aaron told me. "A lot of them didn't know anything about solar energy and many people installed solar heating just to get the tax break.

"But a good deal did get accomplished and a real industry started to form, then the Reagan Administration came in and swept away all of the tax incentives for alternative energy sources. That just killed the movement. Of course, they kept all the tax breaks for the oil and coal industries, they even increased them."

Solar energy is also clean and safe. "Cleanandsafe," as solar advocates will tell you. They imply, or may even tell you outright, that nuclear energy is dirty and dangerous. In elementary school, those were fighting words for me, since my father designs nuclear fuel. I viewed any attack on nuclear power as an insult which could be settled only with a fistfight at recess.

Discussions about energy policy, even among friends, can quickly become emotionally charged since the issue involves fundamental values. Solar advocates believe in walking to work, eating organically grown foods, and living simply, like Thoreau. Proponents of nuclear energy believe in General Electric, General Motors, and General Foods.

Our first stop was in Lexington, at Doug Holmes's place. Doug Holmes is a consulting engineer and makes his living giving practical advice. He has waged a lifelong battle against inefficiency and sloppy design.

Not so long ago Doug helped design a sewage treatment plant that forgoes modern technology for more traditional means. "People aren't the only ones with sewage to treat," he told us. "Every animal out there makes some, and Nature takes care of it." Modeled on a wetlands, his plant is a series of tanks open to sunlight. The sewage flows through so slowly you can't see it move. At the front end, there are only bacteria. Farther down you can find worms, shrimp, and then fish. "When we wanted to start the plant running, we needed all the little beasties you find in nature, so we went to a few ditches around Providence and collected a bucket of slop, then poured that mess into our tank."

When we all arrived Doug led us down to the greenhouse on the south side of his house. When the house was built in 1979, he purchased the greenhouse armature from a garden store that was going out of business. "If you are ever going to build a greenhouse, use sliding-door glass. Sliding door replacements are the cheapest double-glazed glass on the market."

The floor of the greenhouse is a right triangle with the legs, 15 feet long, pointing south-east and south-west. In the winter, when the sun is low in the sky, the greenhouse receives light throughout the day. In summer, the house walls shade the greenhouse in the morning and evening so that sunlight enters for only four or five hours.

In winter, the sun heats the greenhouse air which then flows up a vent at the top of the greenhouse, through the attic, and down a space in the northern wall. A blanket of heat envelopes the whole house.

The greenhouse cost $10,000, but Doug figures that he has saved that much, easy. "Some people say you have to be a little crazy to build a house in New England without a furnace, but once you make that leap of faith, you need no blower, no ducts, no radiators. You start 5000 dollars ahead."

Under the south-facing windows pigmented concrete floor absorbs heat during the day and radiates at night. "We call that poor man's Italian tile. The concrete costs 50 cents a square foot, tile would do the same job but costs ten times as much," Doug said.

The coldest the house gets is 55 degrees Fahrenheit. Doug spends 50 dollars a year to heat his home on a half-cord of wood that is burned on the coldest winter days. Two-thirds of the heating is done by the sun, ten percent from the two pot-bellied stoves. The rest comes from "heat of occupancy": the oven, the refrigerator, light-bulbs, and people. Doug looked at the 15 of us in his living room. "Right now, all of you are giving me 100 watts," he said.

Someone asked, "What about air management?" Doug replied, "We quit having colds in the winter when we moved into this house. It is the moisture from the plants. Everybody else gets all dried out. Our air management consists of opening the windows for ten minutes on a warm winter day if the humidity gets too high."

As Doug talked about his house, the phrase "design criteria" came up again and again. There are, he said, "no flourishes, no filials, no shades, no shutters." But that doesn't mean the house lacks elegance, just that everything has a purpose. "One thing that always bugged me about houses was that you can't get at anything, so everything here is accessible," Doug said. "You open a panel in the wall to get at the wiring and plumbing."

"We used to keep a book for visitors to sign, but got tired of it. We've had over 3000 people come and see the house, but as far as I know no one has built another house like it."

Few people could afford to. The tax assessor, who Doug said "didn't really know what to do with this place," finally guessed it was worth $380,000, three times what it cost to build ten years ago.

At the next stop on our morning tour, Jim Serdy pointed to the roof of a house which is completely covered in solar panels. "This started as an attic renovation, and sort of evolved."

Jim is a solar professional; he installs solar heating systems in houses. Jim spoke to us in the technical language of solar contracting. He spoke of structural attachment points, insulated thermal blinds, weather surfaces, triple glazed window systems, release temperature, mean-radiant temperature, stick-framing, R-factors, maintenance-free super-insulated maximum-efficiency collectors, and unstratified heat.

We went into the basement and saw a 2000-gallon water drum that Jim had made out of copper. Water heats in the solar panels up on the roof, and flows down to this thermal bank. An industrial computer listens to thermometers throughout the house and controls a pump which sends hot water to cool places. The water flows through a rubber tube under the strips of metal that Jim called "radiant." The water warms the radiant, and the radiant warms the room.

"It all seems sort of complicated. How hard is it to run this equipment," a woman in the group asked Jim. Jim said, "Well, it helps if you have an engineering degree or some technical background, but it isn't necessary by any means."

Someone else asked how much the system costs to operate.

Jim said, "Our data logging has not been vigorous." We weren't sure what he meant.

On the ride to our final stop, I asked Aaron if that solar system was saving the owners money or not. He said, "Well, the economics are tough. You have to really want to go solar. If all the parts were mass-produced it would be a lot cheaper, but Jim has to make all of that equipment custom."

"Lost Farm" is painted on the mailbox at Will Hapgood's place in Bolton, Mass. and if you aren't trying to reach his property you may well be lost. The road is not a main thoroughfare in town. When we parked and walked towards the house, a short, wizard-like figure dressed in blue jeans, hiking boots and a T-shirt hailed us from where he was working in the garage. "Y'all come in your Volkswagens?" he shouted. That was Will.

Will recently quit work and sold the rights to his artificial intelligence expert system called First Class. Now he is "unemployed," although one gathers that the proceeds from the sale are enough to support him. Nailing rafters in the garage, he looked as comfortable with a hammer as he probably does with a keyboard.

The house itself is an American mini-castle--half Aspen lodge, half Newport mansion. The solar heating in this house is a mere incidental, just one of Will's many idiosynchrosies. When Will had the house built a year ago, price was not an issue. Down stairs, there is one of those indoor swimming pools where you swim in one place and the water gets pumped by you. Sort of like walking on a treadmill, but more trendy.

Jim was with us again; he had done the solar work here as well. By this point I had had about enough lecturing on solar power for one day. There was the same copper tank in the basement and the same talk about thermal efficiency, floor radiant and sweat equity.

Will and his house were more interesting than the discussion of direct gain and thermal performance. The whole first floor of the house was one open living area, from bedroom to kitchen, and a fireplace rises from the center of the room. The fireplace and chimney are a twisting, trunk-like work of masonry, made of brick with veins of rocks cutting through. Picture an old gnarled oak tree, substitute brick and stone for the wood, and you have an idea what the fireplace looks like.

"We wanted to get an artist from Provincetown to do the job," Will said, "But the trip was too big for him and it didn't work out. So we got a local artisan to do it. It took him two weeks, and it would have taken the artist a year. Kind of makes you wonder about the meaning of art, doesn't it?"

A tower about 12 feet square stands one story higher than the house, and on the third floor there is a room bare of furniture, with windows on all four walls. What is the function of this place, I wondered. Will told me, "Oh, I go there to sit and think."

A 1966 graduate of Harvard, he seems to know how to live well. Now that he is unemployed, he will putter around the house while he works on his next project, which he speaks about guardedly. His wife is president of MassChoice, manages some businesses, and does some science writing on the side.

One of the group said. "I've passed by this place before, but you can't see it from the road."

Will replied, "That's the idea."