DEZHOU, CHINA -- Uprooting the last traces of rural life on the edge of this northern Chinese city, laborers with chain saws spent a recent morning cutting down trees to make way for a hulking factory. A big red banner trumpeted the future for what used to be farmland: "The Biggest Solar Energy Production Base in the Whole World."

Across China, villages are being turned into pollution-belching industrial zones, but nature's retreat on the outskirts of Dezhou boasts a paradoxical purpose -- protecting nature.

"This is an experiment. It is a big laboratory," said Huang Ming, an oil industry engineer turned solar energy tycoon, who is driving one of China's boldest efforts to promote, and profit from, green technology.

At the center of his outsize ambitions is Solar Valley, a massive exercise in social, economic and ecological engineering. As part of the project, tens of thousands of farmers have been moved into concrete apartment blocks and their land is being converted into what Huang and Dezhou's planners hope will be China's clean-technology answer to California's Silicon Valley.

The $740 million plan has attracted about 100 companies and spawned factories, a research center and wide boulevards illuminated by solar-powered lights. It highlights the promise -- as well as the limits -- of China's efforts to reconcile breakneck economic development with environmental concerns.

Short of a calamitous economic collapse or a game-changing technological breakthrough, China's chances look slim: Its mostly coal- and oil-fueled economy is growing so fast that its real but relatively modest green gains simply can't keep up.

In Dezhou last year, municipal authorities spent more than $10 million to install solar lighting along miles of road. They also put up posters cheering low-carbon living on billboards once devoted to political slogans. During that period, though, residents bought 60,000 new cars, an increase of 114 percent over 2008.

All the same, a mix of raw capitalism and socialist planning is giving companies such as Huang's Himin Solar Energy Group a shot at making a difference -- and at boosting their bottom lines.

Huang's company is the world's biggest producer of solar water heaters, as well as a pioneer in niche products such as sun-warmed toilet seats and solar-powered Tibetan prayer wheels. Now it has opened a low-carbon five-star hotel and is building Utopia Garden, a gigantic, eco-friendly luxury apartment complex -- both with solar-heated pools.

"Renewable energy doesn't mean people have to be uncomfortable," Huang said in an interview at his Dezhou corporate headquarters, the Sun-Moon Mansion, a fanlike structure studded with photovoltaic cells and sun-collecting vacuum tubes.

Huang is known in these parts as the "sun king," but he said, "I prefer to be called solar madman."

Dezhou, a gritty city of 600,000 with a surrounding suburban sprawl housing 5 million people, used to be known mainly as a producer of braised chicken. Today, it touts itself as China Solar City, a hub for clean-tech manufacturing.