On Thursday the House Energy and Commerce Committee ramped up its ongoing investigation of the federal government’s $535 million loan to Solyndra, a solar energy company that recently announced it will file for bankruptcy.

In a letter to the White House, committee Chairman Fred Upton and Oversight and Investigations Subcommittee Chairman Cliff Stearns requested a scheduled briefing on the matter by no later than September 12 and asked for all documents related to the loan guarantee between Solyndra and the White House.

In 2009, Solyndra was the recipient of a half-billion-dollar loan through the Department of Energy, funded by stimulus monies. The company was touted as a model of President Obama’s green energy initiative. But despite heavy backing by the federal government, the company struggled to meet expectations, falling fall short of the 4,000 or so jobs it was projected to create.

In November of 2010, the company announced it was postponing a planned expansion and laying off several hundred employees. In February of this year, the Department of Energy was forced to restructure the terms of its loan with Solyndra. Two days ago it announced it was filing for Chapter 11 bankruptcy and was laying off some 1,100 workers.

The House Energy and Commerce Committee has been investigating the details of the loan since February. It has subpoenaed the Office of Management and Budget for documents, and the committee says it has found evidence of White House involvement in Solyndra’s loan application.

“We have learned from our investigation that White House officials monitored Solyndra’s application, and communicated with DOE and Office of Management and Budget (OMB) officials during the course of their review in 2009 and when those officials were restructuring the Solyndra deal this year,” Upton and Stearns wrote. “Documents received by the Committee also show that DOE and OMB officials were aware of the White House’s interest in the Solyndra loan guarantee. In addition, we are also aware that a major investor in Solyndra, George Kaiser, was a bundler for President Obama’s 2008 campaign.”

Kaiser in fact raised somewhere between $50,000 and $100,000 for Obama’s campaign. He also personally donated $53,500. Many other Solyndra executives and board members donated to Obama as well.

For its part, the White House insists the aims — and outcomes — of its green energy initiative are still good.

“While we are disappointed by this particular outcome, we continue to believe the clean-energy jobs race is one that America can, must and will win,” White House spokesman Eric Schultz said today in an emailed statement.