WASHINGTON — Energy Secretary Steven Chu said today that no one from the White House ever contacted him to make a political decision on a half-billion-dollar loan to a California solar company that later went bankrupt.

Testifying under oath on a widening controversy, Chu said he was unaware of his staff predictions in 2009 that Solyndra was likely to face severe cash-flow problems. He said that market changes which led to a steep decline in the price of solar panels were “totally unexpected.”

Solyndra went belly-up after getting the $528 million loan from the government, and Chu told the House Energy and Commerce Committee that he made all decisions involving the loan to the solar-panel manufacturer.

Chu also said he doesn’t expect taxpayers will recover much of the money lost in the transaction.

The secretary’s position before the committee was that politics played no role in the decisions on the loan, despite e-mails and other documents released by the panel that revealed some pressure from the administration on Solyndra to delay an early round of layoffs until after the 2010 elections.

Other documents showed that campaign donor George Kaiser was involved in discussions about the loan program.