PHOENIX, Ariz. — A Spanish company is planning to take 3 square miles of desert southwest of Phoenix and turn them into one of the largest solar power plants in the world both in size and capacity, Arizona and Spanish officials announced Thursday.

PHOENIX, Ariz. — A Spanish company is planning to take 3 square miles of desert southwest of Phoenix and turn them into one of the largest solar power plants in the world both in size and capacity, Arizona and Spanish officials announced Thursday.

Abengoa Solar, which has plants in Spain, northern Africa and other parts of the U.S., could begin construction as early as next year on the 280-megawatt plant in Gila Bend — a small, dusty town 50 miles southeast of Phoenix. It could be producing solar energy by 2011.

Abengoa would build, own and operate the $1 billion plant, known as the Solana Generating Station.

Arizona Public Service, the state's largest utility, would pay the company $4 billion over 30 years for the energy produced, estimated to be enough to supply up to 70,000 homes at full capacity.

APS President Don Brandt said the plant will make Arizona the solar capital of the world.

"In Arizona, the sun and the heat practically define our way of life, especially during the summer," he said. "Throughout the state, one hears the phrase, 'Boy, it's hot.' But soon that radiant heat will become an energy source that powers homes, businesses and lives."

APS filed for approval of the plant with the Arizona Corporation Commission on Thursday. The plant also hinges on an extension of the federal solar investment tax credit, which APS and Abengoa said they're confident will happen.

If approved, the plant will triple the amount of renewable energy APS produces. Now, about 11/2; percent of the utility's energy comes from renewable sources.

The Arizona Corporation Commission, the state's regulator of public utilities, is requiring utilities to get 15 percent of their electricity from renewable sources by 2025, with annual increases of roughly 1 percent.

The Solana plant will bring APS to around 5 percent in 2011, said Don Robinson, senior vice president of planning and administration at APS.

Unlike most solar energy, Solana will use the sun's heat, not its light, to produce power. Gila Bend can get as hot as 120 degrees in the summer.

Abengoa CEO Santiago Seage said the plant will use thousands of giant mirrors to harness the sun's heat. That will heat up liquids, which will spin turbines — just like coal or other power plants but without the pollution.

He said using heat will allow the plant to produce power even after the sun has gone down.

"We receive the heat from the sun and we use a fluid that becomes very hot. And we can keep it hot for a long time and release that heat for a long time," he said. "It's like coffee. You can make it hot, keep it hot for a few hours and drink it anytime you want."

On the Net: Abengoa Solar:www.abengoasolar.com/sites/solar/en/ Arizona Public Service:www.aps.com/