New York Times

Two years ago, this gritty mining city hosted a brief 21st-century gold rush. Long famous for coal, Puertollano discovered another energy source it had overlooked: the relentless, scorching sun.

Armed with generous incentives from the Spanish government to jump-start a national solar energy industry, the city set out to replace its failing coal economy by attracting solar companies, with a campaign slogan: “The Sun Moves Us.”

Gherardo Corsini, director of electric vehicle implementation at General Motors’ Opel/Vauxhall unit, made his way Sunday to Geneva from Germany more quietly than most. He was at the wheel of a prototype of the Opel Ampera.

“Getting lots of curious looks at the rest area,” one of Mr. Corsini’s passengers, Dietmar Thate, manager of social media for Opel, tweeted after the car made a short stop Sunday.

It was primarily a symbolic gesture. Way back in 1979, in the midst of an energy crisis, Jimmy Carter had solar panels installed on the roof of the White House. They were used to heat water for some White House staffers.

“A generation from now,” said Mr. Carter, “this solar heater can either be a curiosity, a museum piece, an example of a road not taken, or it can be a small part of one of the greatest and most exciting adventures ever undertaken by the American people, harnessing the power of the sun to enrich our lives as we move away from our crippling dependence on foreign oil.”

If electric cars have any future in the United States, this may be the city where they arrive first.

The San Francisco building code will soon be revised to require that new structures be wired for car chargers. Across the street from City Hall, some drivers are already plugging converted hybrids into a row of charging stations.

Last year, when Jonathan Smith was still the president of Earth911.com, a Web site dedicated to recycling, he said he would often board a plane after a speaking engagement or a day of meetings with a dead cellphone in hand.

With limited recharging options available, “it was really frustrating,” he said. “Having access to a working port or finding an open plug during layovers at the airport was just too unpredictable.”

China vaulted past competitors in Denmark, Germany, Spain and the United States last year to become the world’s largest maker of wind turbines, and is poised to expand even further this year.

China has also leapfrogged the West in the last two years to emerge as the world’s largest manufacturer of solar panels. And the country is pushing equally hard to build nuclear reactors and the most efficient types of coal power plants.

Better Place, the closely watched start-up that hopes to create vast networks of charge spots to power electric cars, is set to receive a vote of confidence on Monday, in the form of $350 million in new venture capital.

Although Better Place will most likely require billions more in financing, this investment is an important step for the company and its chief, Shai Agassi, an Israeli-American software executive who founded the company in 2007.

Carlos Ghosn, the Renault chief executive, sought over the weekend to defuse an employment conflict with the French government, telling President Nicolas Sarkozy that the automaker would split production of its new Clio model between France and Turkey and would produce its new electric vehicle entirely in a plant near Paris.

After a disastrous year for the auto industry, carmakers are working hard to exude optimism and confidence at this year’s auto show.

On that score alone, the winner may be the Chinese company BYD Auto, which created a stir on Tuesday by announcing that it plans to start selling an electric car in California by the end of this year. That would make BYD the first company to sell Chinese-made vehicles in the United States.

As it moves rapidly to become the world’s leader in nuclear power, wind energy and photovoltaic solar panels, China is taking tentative steps to master another alternative energy industry: using mirrors to capture sunlight, produce steam and generate electricity.