U.S. Energy Secretary Steven Chu announced offers of conditional loan guarantees of up to a combined $4.5 billion to support three advanced solar power facilities in California.
"Together the projects will power hundreds of thousands of homes with clean, renewable power and increase our global competitiveness in the clean energy economy," Chu said in a statement.
Combined, the three facilities would produce enough power to meet the yearly energy demands of more than 225,000 homes and avoid more than 1.8 million tons of carbon dioxide emissions.
The loans are for AV Solar Ranch, Desert Sunlight and Topaz Solar Farm.
The so-called SunShot program by the U.S. federal government aims to spur American innovations to reduce the costs of solar energy.
In his State of the Union address in January, President Barack Obama laid out a clean-energy target of meeting 80 percent of U.S. energy needs with clean sources by 2035.
The Energy Department has spent more than $1 billion on solar energy research in the past decade.