Chu said the decision to give the federal loan to the troubled Northern California solar company was not politically motivated.
"I want to be clear: Over the course of Solyndra's loan guarantee, I did not make any decision based on political considerations," he said.
The Fremont-based company went belly-up after getting the loan from the government.
Chu admitted he was unaware of dozens of key details that led to the debacle over Solyndra, but he declined several opportunities to apologize.
"Certainly knowing what I know now, we'd say `no,"' Chu said during a daylong hearing before the energy panel's subcommittee on investigations. "But you don't make decisions fast-forwarding two years in the future and then go back. I wish I could do that."
Chu took responsibility for the disastrous 2009 loan and said he was not aware that Solyndra was facing severe cash-flow problems.
"I am aware of it now," he said at least five times.
He blamed the company's demise on "totally unexpected" market changes - including an influx of cheap imports from China and the collapse of the European market for solar panels - that led to a steep decline in the price of Solyndra's product.
Solyndra was the first renewable-energy company to receive a loan guarantee under a 2009 stimulus law.
The Associated Press contributed to this report.