Washington ? The Obama administration ignored repeated warnings about a clean-energy loan program that has become an embarrassment for the White House amid the collapse of a California solar energy company that received more than $500 million in federal loans.

At least three reports by federal watchdogs over the past two years warned that the Energy Department had not fully developed the controls needed to manage the multibillion-dollar loan program that provided more than $528 million to Solyndra Inc., a now-bankrupt solar panel manufacturer.

The Silicon Valley company was the first renewable-energy company to receive a loan guarantee under the 2009 stimulus law, and the Obama administration frequently touted Solyndra as a model for its clean energy program. President Barack Obama visited the company’s Fremont, Calif., headquarters last year.

Even as Obama praised the company’s plans to hire more than 1,000 workers, warning signs were being sent from within the government and from outside analysts who questioned Solyndra’s viability as a “going concern.”

Emails obtained by The Associated Press show that a White House official dismissed reports about Solyndra’s gloomy future. An email from Greg Nelson, a White House official who had been involved in the planning of Obama’s May 2010 trip to Solyndra’s headquarters, to a Solyndra executive downplayed a July 2010 news story in a trade publication that criticized the company’s financial health.

“Seems B.S.,” Nelson wrote.

A 2009 report by the Energy Department’s inspector general warned that the DOE lacked the necessary quality control for the loan guarantee program, which was created in 2005 to support clean-energy projects that could not obtain conventional bank loans due to high risks.

In July 2010, the Government Accountability Office said the Energy Department had bypassed required steps for funding awards to five of 10 applicants that received conditional loan guarantees.

The report did not publicly identify the companies that were not properly vetted, but congressional investigators say one of them was Solyndra. The company was the first to receive a loan guarantee after the program was expanded under the 2009 stimulus law.