Living "off the grid" can conjure fantasies of Swiss Family Robinson-style ingenuity in paradise. Or, for those with less love of roughing it, it can simply remind them of the hardscrabble self-reliance throughout much of the developing world, where millions cook over fires, bathe in streams, and consider the glow of a bare light bulb a luxury.

In the United States, off-the-grid living – without relying on government entities or utility companies to provide electricity, heat, gas, and water – often is associated with gritting it out on the survivalist fringe.

But an increasing range of Americans are leading a snug, even smug, lifestyle totally or mostly unhitched from public utilities. Using nature – the sun, wind, water, and the earth itself – they cheaply warm and cool their homes and power everything from a blender to a giant flat-screen TV to a raging hot tub. And with the constant concern about global warming and messy dependence on fossil fuels, it's natural that growing numbers of Americans – "the foot soldiers" of energy independence, as one expert calls them – would begin taking steps to untether themselves from the grid.

For Wayah Hall, going off the grid in a cabin 26 miles from downtown Asheville, N.C., was a way to live in harmony with nature and avoid reliance on electricity that comes from the region's coal-burning power plant that pumps smog into the famous Blue Ridge Mountains haze.

Mr. Hall, an outdoor-skills instructor, and his wife, Alicia Bliss Hall, a natural healer, live in a kind of off-the-grid neighborhood with another young couple: Jason Brake, a professional muralist, and his wife, Diana Styffeler, a mountain bike excursion leader. Their two cabins, nestled in temperate rain forest, are powered with electricity that comes exclusively from solar panels mounted on a wagon that they wheel around the property to catch the best rays. Their water comes from a swiftly flowing stream; wood-burning stoves heat the cabins and even an outdoor hot tub; and indoor, waterless composting toilets built decoratively out of tree stumps mean they don't need a sewer system. They're installing a hydropower system in the stream that will add to the solar power.

Their existence appears quite rustic – and the "sustainable" lifestyle depends a whole lot on them to sustain it with such work as wood chopping and wagon pulling. But they say they have all the creature comforts they need, and – if February's record snowstorm is any gauge – some their neighbors need, too. When public power outages left on-the-grid neighbors in dark and chilly homes, a dozen of them congregated in the Halls' self-sufficient glow: a lighted cabin, where they cozied up to the wood stove, recharged their cellphones, and even enjoyed a soak in the hot tub.

"We didn't even realize the power had gone out until our friends started coming over looking for refuge," says Ms. Hall.

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Off-the-grid living for Paula and William Cirone has a more suburban look and feel, as well as a different motive. In 2001, the Texas natives moved to central Illinois, where Mr. Cirone was taking over a family company. Their hearts were set on buying and building on woodland near Farmington that he had hunted and fished two decades before. But an issue over easements meant the utility company could not extend lines to connect to their new home. Going off the grid was the only way to realize their dream.

Ms. Cirone was initially nervous, not wanting to give up her comfortable lifestyle – being able to throw in a load of laundry, or flip on the TV or microwave, whenever she felt like it. But the Cirones built a comfortable, spacious home powered entirely by wind and solar energy, with a geothermal system for heating and cooling.

"It was a little scary at first, wondering if this was all going to work," says Ms. Cirone. "But we didn't have to make any sacrifices or concessions, and we are doing something that benefits the environment. It's kind of exciting to realize that you are on the cutting edge. It's really kind of neat."

While investment in the technology added $100,000 to the cost of building their home, they admit a certain satisfaction in just the fact that they're generating their own clean energy.

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There are about 750,000 off-the-grid households nationwide, estimates Nick Rosen, author of "Off the Grid: Inside the Movement for More Space, Less Government, and True Independence in Modern America."

Improving technology means that – while still not cheap – living off the grid is more realistic and comfortable than ever before. In an age of extreme economic insecurity plus concern about the effects of using fossil fuels – witness the BP oil spill and a host of recent coal-mining disasters – living off the grid gives people a feeling of structural, financial, and emotional independence. It lets them plan and control their energy use, with no fear of sudden blackouts. It liberates them from the grip of government regulators and utility companies – not to mention reducing their utility costs, after the initial investment is paid off. And it hints at the potential of a different energy future, free of the environmental and social costs of using fossil fuels.

Mr. Rosen estimates that the number of people living off the grid in the US is growing by about 10 percent per year. His website www.off-grid.net features an interactive map that shows where people are living off the grid and helps them connect to share ideas.

"There's much more competition for the amount of fossil fuel available: Prices will go up, availability will go down. So it's right to prepare for that era," Rosen explains. "Going off the grid is like insuring yourself against a time the lights may go out. In the 1970s you had a lot of old-style hermitlike survivalists. But these people are different. This isn't the Stone Age anymore; you can live a quite comfortable life."

For some, going off the grid means demonstrating that clean energy can fuel a lifestyle comparable to those lived on the grid. For others, going off the grid is an intentional part of "downscaling to a simpler existence," as Rosen puts it.

Most clean-energy experts don't see off-grid living as the solution to the nation's energy crisis. They say large- and medium-scale renewable-energy systems are the way to go. Think: a geothermal setup heating and cooling 200 homes. Or a few wind turbines providing electricity for a suburb. Or off-the-grid ecovillages like those near Taos, N.M., and Big Bend, Texas, where houses are built with cutting-edge sustainable design and materials and share renewable-energy resources.

Most renewable-energy policy and technology experts advocate that people generating their own electricity also stay connected to the grid, when possible, so they can send clean energy back to the grid when they're making more than they can use.

Even if generating your own electricity for a single home – as the Cirones do – isn't the most efficient choice, these do-it-yourself energy pioneers may be the vanguard of the energy future, the dreamers and doers who show that it is possible to bypass mainstream commercial utilities and fossil fuels and still live comfortably and productively.

"If we are going to move toward an age of energy independence, these are the foot soldiers, the people who show us what we have to do," says Rosen.

• • •

Living off the grid typically requires a significant investment. Hall figures that once the hydropower system is finished on his property, he will have invested about $15,000 on energy systems. Most North Carolinians spend several hundred dollars a month for electricity, water, and heat. So the Halls will have paid off their investment in a decade.

Cirone says he doesn't expect to see a financial payoff anytime soon on his $100,000 investment in higher-end, higher-capacity systems, but the nonmonetary benefits are many. Their two sons, an electrical engineer and a doctoral student with an energy focus, are so enthused about the potential of off-the-grid living that they are launching a renewable-energy consulting company.

"There's a lot more return on investment than just money," Cirone says. "I believe inside our own basic spirit is the fact we want to do what's correct for the environment and, ultimately, the universe. We hope this proves to anyone who even considers [going off the grid] that if you don't want to give up anything in your lifestyle, you can use alternative energy and still have all the amenities you want."

• • •

Solar energy is the most popular and fastest-growing way to generate your own power. Improving technology, a glut of solar panels on the world market caused, in part, by the end of European subsidies that had driven production, and American government incentives mean solar power is an increasingly affordable option. San Diego, like some other cities, has started a program to lend money to home-owners for the purchase of solar panels, with loan payments added to the property tax over 20 years.

Though the Southwest and South are solar hot spots, studies show it is a viable option in seemingly gloomy locales like the upper Midwest and the Northeast. (See story on page 30.)

Residential solar power increased by about a third in 2009, with roughly 40,000 new installations, says Seth Masia, of the nonprofit American Solar Energy Society. Such a system – usually four kilowatts – might cost about $10,000 to purchase and install. If the savings on electric utility bills is, say, $80 a month, the investment should pay off in about a decade.

Through the national program One Block Off the Grid, homeowners band together in groups of 100 to negotiate with solar panel suppliers for bargain deals.

Many households augment solar panels with wind power – a good combination since wind tends to pick up when the sun goes down or is obscured by storm clouds. Homes typically use "small wind" power – with turbines that generate less than 10 kilowatts. But "small wind" is not a new concept – wind power has been harnessed for hundreds, if not thousands of years, for such things as transportation, milling, and pumping water. But in recent years it has become increasingly popular. The "small wind" market grew 15 percent in 2009 despite the recession, says Ron Stimmel, small systems manager for the American Wind Energy Association.

The five-kilowatt turbines needed to power an average home range from 30 to 140 feet tall and cost about $30,000. Turbines that produce less than one kilowatt – to supplement solar panels or electricity from the grid – can cost less than $10,000.

Wind turbines aren't as easily suited to a wide range of buildings and geographic locations as solar panels, because they usually require up to an acre of space, unobstructed by tall buildings, hillsides, or trees. Wind turbines can be mounted on roofs or parapets – as in the Bronx apartment complex featured on page 29 – but only if the structure is strong enough. Zoning restrictions can make it difficult to install wind turbines, so proponents are pushing for wind-friendly codes.

And generating one's own electricity isn't the only way to bypass or reduce dependence on commercial utilities. In many homes, a large amount of electricity is used to run air conditioners, and electricity, natural gas, or oil is used for heating. But harnessing natural sources eliminates or reduces this consumption. The simplest way is through architecture that naturally keeps the home at a stable temperature, as John Sagebiel's home near Reno, Nev., featured on page 30, demonstrates.

"Passive solar" means a home is designed so that the sun's heat is captured and stored naturally. Windows are placed to maximize sunshine exposure when desired, and thick concrete floors and walls hold heat. Recently developed "smart" windows and drywall even react to the temperature outside by keeping heat out or drawing heat in.

Geothermal energy is a high-tech, relatively expensive way to heat and cool a home. But from densely packed Manhattan to the plains of the Midwest, it is increasingly common for households to plumb deep in the earth to heat and cool.

Commercial geothermal plants take volcanic heat deep in the earth to create steam to turn a turbine and generate electricity. But for individual homes, geothermal cooling and heating systems pump water through underground pipes that heat or cool the water to the constant temperature of approximately 55 degrees F. near the Earth's surface. "You are using water as the vehicle for moving the latent temperature of the Earth," says Martin Orio, general manager of the company Northeast Geo, a New Hampshire company. There are different models, but all essentially rely on fluid circulated through tubing that can be installed up to about 200 feet deep vertically, or horizontally about 10 feet deep and roughly as wide as the property. In winter, the fluid is warmed below the earth, then heats air using a compressor and standard technology known as the refrigeration cycle. In summer, the cycle is reversed so heat is essentially extracted from the home and sunk back into the earth.

In relatively soft or sandy soil, pipes for a geothermal system can be run horizontally or in a variety of loops. On top of hard bedrock, one must drill down – a more expensive proposition – to create a "standing column" system where fluid is circulated through a vertical cylinder with a "riser pipe" in the middle. Water moves up the center, then flows back down the outer ring of the cylinder.

Geothermal systems are typically built with the home; retrofitting is expensive and difficult, though technological innovations may soon change that. As it has become more economically practical, geothermal systems also have gained "cachet" as a status symbol, says Andrew Collins of the New York City firm P.A. Collins P.E. Consulting Engineers. The firm has designed geothermal systems at the new Liberty Island Retail Pavilion and for upscale homes in Tribeca, the Upper East Side, and on Long Island.

Meanwhile, on or off the grid, experts say the cleanest, cheapest energy is the energy not generated at all. Weatherizing a home is the best thing for the environment and the wallet.

"It's great to have geothermal or photovoltaic [solar], but we like to stress you don't need those technologies to have a real energy-efficient home," says Nate Kredich of the US Green Building Council. "You need a tight envelope – good insulation, tight windows, everything air-sealed. That goes an awful long way."

And new types of solar, wind, and geothermal systems and energy-efficiency innovations are being developed all the time.

"People just start looking to see what resources are around them, attempting to tap anything and everything that makes sense," says Steve Brauneis, senior consultant at the Rocky Mountain Institute, a national leader in renewable-energy research. "We'll see all sorts of things sprout up. That's the human spirit."

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