"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.