Energy Secretary Steven Chu is stepping down.
The Energy Department said Friday Chu has offered his resignation to President Barack Obama. Chu won a Nobel Prize in physics but came under questioning for his handling of a solar energy loan.
Chu is a former director of the Lawrence Berkeley National Lab. He drew fire from Republicans who criticized his handling of a $528 million federal loan to solar panel maker Solyndra, which later went bankrupt, laying off its 1,100 workers.
In a farewell letter to Energy Department employees, Chu responded to his Republican critics writing, "While critics try hard to discredit the program, the truth is that only one percent of the companies we funded went bankrupt. That one percent has gotten more attention than the 99 percent that have not."
"The test for America's policy makers will be whether they are willing to accept a few failures in exchange for many successes," he continued.
The White House said Chu retained Obama's confidence, but Chu was widely expected to leave following Obama's re-election last fall.
"I would like to return to an academic life of teaching and research, but will still work to advance the missions that we have been working on together for the last four years," Chu said in his letter. He indicated he plans to stay on until the end of February and that he "may stay beyond that time so that I can leave the Department in the hands of the new Secretary."
In a written statement, President Obama said, "I want to thank Secretary Chu for his dedicated service on behalf of the American people.
"As a Nobel Prize winning scientist, Steve brought to the Energy Department a unique understanding of both the urgent challenge presented by climate change and the tremendous opportunity that clean energy represents for our economy," he continued. "And during his time as Secretary, Steve helped my Administration move America towards real energy independence."