UPDATE 1-US grants $1.4 bln loan guarantee to BrightSource

* BrightSource loan guarantee to help build 3 solar plants

* This is sixth DOE loan guarantee for a renewable project

* White House touts green energy as way to help economy

By Ayesha Rascoe

WASHINGTON, Feb 22 (Reuters) - The U.S. Energy Department on Monday said it granted has BrightSource Energy Inc $1.37 billion in conditional loan guarantees, the largest federal loan commitment offered to a renewable company so far.

The conditional loan guarantees are supposed to help BrightSource build three utility-scale solar power plants for its Ivanpah Solar Complex, which will be located on federally-owned land in the Mojave Desert in southeastern California.

The proposed plants are expected to generate about 400 megawatts of electricity and power about 140,000 California homes.

This is the sixth conditional loan guarantee offered to renewable energy companies by the Obama administration, which has touted green energy investments as a way to create jobs and increase international economic competitiveness.

"We're not going to sit on the sidelines while other countries capture the jobs of the future -- we're committed to becoming the global leader in the clean energy economy," Energy Secretary Steven Chu said in a statement.

Construction on the first plant in BrightSource's solar complex is expected to begin during the second half of this year, with commercial operations beginning in 2012. All three plants are expected be on line by 2014, a company spokeswoman said. (Additional reporting by Tom Doggett; Editing by Marguerita Choy)