ERIC ANDERSON'S house is a dazzling structure with oodles of windows that offer views of ocean and salt marshes in every direction. Bougainvillea grows like Jack's beanstalk from the first-floor greenhouse to the second floor. Spiral staircases snake upward to an outdoor widow's walk. There are four suites and a gourmet kitchen. Every appliance one might expect - dishwasher, TV, CD player, washer and dryer is present. But the unusual feature of this magnificent home is that it's powered by the sun, so Mr. Anderson doesn't get a utility bill.
The house is located on a sliver of peninsula in Plymouth, Mass., that is accessible only by four-wheel drive and requires a cheerful tolerance to several miles of bumps and craters. Ever since the power lines that sent electricity were downed in a 1938 hurricane, most of the small homes here have used generators for energy needs.
Anderson's home, which was built onto its existing 1724 structure in 1986, is one of about 100,000 homes in the United States that operate completely off the utility grid. The pioneers of this movement - the number of ``off-the-grid'' homes has doubled over the past five years - live in residences as diverse as their lifestyles. Their homes are powered by wind, sun, or water and range from small cabins to earthen dwellings to elegant abodes. But they all share one common denominator.
``The people living this way are making a very hopeful statement,'' says Michael Potts, who visited more than 100 independent homesteaders across the United States for his book ``The Independent Home'' (Chelsea Green Publishing Company). ``They're saying ... I'm willing to give a certain amount of my time and energy to arranging my life so that I'm not too weighty on the world.''
AS the supply of fossil fuels dwindles, people will be forced to learn how to depend on renewable energy sources, says Steven Strong, an architect who started Solar Design Associates in Harvard, Mass., one of the only firms in the country that designs solar-electric-powered buildings and engineers their energy-support systems.
``We have maybe three decades,'' Mr. Strong estimates. ``In 30 years, there will be a doubling of population and a doubling of energy demand. We don't have conventional fuels to support that.... The changes we need to make are significant.''
Strong, who designed Anderson's home, and other experts say solar is the most promising renewable for several reasons: The sun is available just about everywhere; the cost of producing the equipment has dropped dramatically as makers gain more experience; and better energy-efficient product design has made it possible to have a comfortable home with modern conveniences.
How does solar power work? The south side of a building is covered with rectangular panels that look like dark blue glass. These are called photovoltaic modules. Photovoltaic is a term that means converting light directly into electricity. The photovoltaic modules are made up of silicon cells treated with certain impurities that make them sensitive to light and capable of creating electrical currents.
The roof of Anderson's 5,000-square-foot house in Plymouth is outfitted with 18 of these photovoltaic modules. In the basement are 16 quart-sized batteries that store excess power from the sun for use at night or on cloudy days. Anderson's refrigerator and stove are powered by gas; he also has a backup generator, which he hasn't used since May. A wood stove in the living room supplements the sun's heat when winter temperatures dip to lower digits.
``It's trouble-free,'' Anderson says of the system. ``You monitor how much electricity you're using [via a wall panel], and if the batteries are low, you might wait until the next day'' to use the dishwasher or other appliances. He says, however, that he has enough power to accommodate several nieces who take two or more showers a day and use hair dryers simultaneously.
But while Anderson and many other individuals have unplugged completely from the utility grid, in many cases because of location, Strong says the fastest-growing market will be for solar-powered homes that work with the utility companies.
In a town near Boston, Genevieve Wyner's solar-electric house is an example of this kind of partnership. Called the Impact 2000 house, the structure was commissioned by Boston Edison Company and designed by Strong in 1983.
The 2,900-square-foot house is built into a small hillside that faces several acres of landscaped gardens. The south roof is covered with 24 photovoltaic modules, six thermal solar collectors that produce hot water, and three skylights. The house uses both solar and electric heat. Because it is already connected to a power grid - Boston Edison - Mrs. Wyner doesn't have batteries that store extra solar energy. Instead, a meter records a surplus or deficiency of electricity: ``If we're collecting more energy, our meter turns backward, which means we become a supplier to Edison,'' Wyner says. That usually occurs during the summer when sunshine is more abundant. For the utility company, summer is a peak season, so getting extra energy reduces its demand. When Wyner and her husband need that electricity, it is given back to them. Wyner estimates 25 percent of their energy comes from the sun.
``It's a symbiotic relationship that everyone benefits from,'' Strong says.
UTILITY companies are starting to see this benefit, he says. Sacramento Municipal Utility District in California is pioneering the way. It recently started a voluntary program that enables the utility to install solar-electric systems on homes in exchange for a 15 percent one-time rate hike. Hundreds of people subscribed to the program. ``Utilities must be proactive partners,'' Strong says. ``The transition can't happen without them.''
The cost of photovoltaic systems is one reason more people haven't switched to solar power. The modules are expensive. Still, the cost has decreased significantly since 1975. At that time, the cost was about $300 per peak watt; today it is $5. A peak watt is the amount of power a photovoltaic device produces at noon on a cold day under full sun. If a photovoltaic module generates 200 watts at $5, the module will cost $1,000.
How much does it cost to take a home off the grid?
``For $3,500 you could put together a system that would be like a cabin - an electrified cabin,'' Mr. Potts says. ``You ... could run a microwave and some of the other nice things of life. Your basic 2,000-square-foot home with washer, dryer, and refrigerator might cost $5,000 to $6,000, though you could easily spend $18,000 if you wanted.'' Strong says each system is individual, depending on different levels of power. Anderson's system, for instance, cost about $30,000, though Strong says it would cost 20 percent less today.
Strong emphasizes that the price is a one-time expense. ``You pay up front for equipment, but there's no maintenance, and your electricity is free for the life of your house.''
Solar ``prices are de-escalating rapidly, and utility rates seem to be increasing at about 10 percent a year,'' says John Schaeffer, president of Real Goods, a California company that has outfitted 20,000 homes with solar systems. ``The lines are poised at a point where they're about to cross. We're right on the verge of it really taking off.''
Strong adds: ``Hundreds of thousands of square miles of roof area is begging to be harvested with sunlight. It's free real estate.''