JØRGEN TRANBERG IS A GAP-TOOTHED dairy and pumpkin farmer. His latest crop is the one-megawatt turbine I climbed. When I first meet him, he's trying to U-turn a tractor carrying a huge bale of hay. "I'm not an environmentalist," he says, flicking ash off his cigarette. "It's a business venture." Down the driveway sits his new Drago Fiesta motorboat, so I'm not surprised when he tells me business is good.

Almost everyone on Samsø, in one way or another, makes money from wind. Turbines are owned by private investors like Tranberg, by the government, or by cooperatives of people who bought shares to finance their construction. The process is democratic in the way so many things are in Denmark; shares cost about $360 each.

Tranberg, for his part, took out a loan to buy his $1 million windmill six years ago,

Investors have seen returns of 8 percent a year, or roughly $100,000 per onshore turbine. Tranberg's is already paid off. "It's enough income for me that I don't have to work."

but the government guaranteed him an above-market price for his power. And the wind, which blows lustily here most days of the year, proved to be an even better friend than he and other islanders had hoped. Investors have seen returns of 8 percent or so a year, which works out to roughly $100,000 per onshore turbine. Tranberg's is already paid off. "It's enough income for me that I don't have to work, but I like to work," he says. Besides, he adds, talking tough for a man in clogs, "we can't put all that shit in the sky from coal. There's too much shit in the air."

The fairy tale of turning pumpkins into turbines is one told frequently on the isle, most notably in the Ecomuseum in the main town of Tranebjerg. There, among the Viking coins and the potato-shaped chocolate bonbons in the gift shop, are posters that explain the history of the Samsø experiment: how in 1997 the green-leaning government and the Danish Energy Agency launched a contest to select the island with the best plan to become energy-sustainable by 2008; how Samsø won and has since spent $70 million on the project; and how European grants also helped subsidize the effort.

The result has been fairly staggering. Between 1997 and 2005, Samsø is estimated to have reduced emissions of global-warming pollutants like carbon dioxide, sulfur dioxide, and nitrous oxide by 142, 71, and 41 percent, respectively. Today, 100 percent of islanders use green electricity, and 70 percent of residences are heated by wind, solar, or biomass systems, including huge, centrally located furnaces that burn straw. Straw is considered carbon neutral because it's a by-product of crops like alfalfa that help absorb CO2 from the atmosphere, just as trees do. The straw is burned in super-hot, super-efficient kilns. Plus the ash is collected and spread back on the fields to fertilize the next cycle. The cows eat the alfalfa, make some damn fine milk, and then the straw goes off to the furnace.

It's so Scandinavian.

I'm staying down the road a few miles with another dairy farmer, Erik Andersen, and his wife, Lise, in the tiny town of Besser. Now in their sixties, they live with their Border collie, Jacko, in a beautiful, simple stucco house. Andersen, who has milked cows all his life, caught the renewables bug in a big way after Samsø won the energy contest. He installed 18 square yards of solar paneling on his barn roof, supplying all his electricity and most of his heat and hot water from April to October. The rest of the year he chops scrap wood from his land to feed his biomass furnace. He's also taken to growing rapeseed, otherwise known as canola, for home-brewed biodiesel.

After serving me aeblekage, a baked apple cake with otherworldly good fresh cream, Andersen shows off his voltage meter. "I like to come out and watch the meter running backwards," he says. He is tall and lumbering and sports a gray buzz cut. Every day he wears overalls and irrigation boots, and he is not a man of many words. "It is interesting to make your own energy," he says.

Next he takes me out to the garage to see his prized new possession: a rapeseed press. The black, beady seeds funnel into the machine, which squeezes the bejeepers out of them. One spout kicks out a narrow cylindrical green mash, the by-product cake, while another spout pours a wan, yellowish oil. Andersen feeds the nutritious mash to his cows so he doesn't have to import soy-based feed. He then filters and pours the oil right into his two tractors and his red Volkswagen Passat. No refining, no cleaning, no mixing with lye or other chemicals.

"What are we going to do when the oil runs out? You need to prepare," he says. By not buying petrol, which costs $6.38 per gallon here, he figures he's satisfying his independent streak.

"Try it," he says, grinning. He wants me to eat his gasoline. Fine. I pour some onto my finger and take a taste. It's nice—light and bland, kind of like oil and salad at the same time.